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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

The role of RpoT;3 in chloroplast development and gene expression

Chandler, Aglaia 02 June 2009 (has links)
The real-time PCR assay method was used to quantify the RNA abundance of twenty-eight plastid genes in a range of tissues and developmental stages of Arabidopsis thaliana. Three groups of co-regulated genes were identified. Three trn genes (Cluster I) showed differential expression in siliques. Genes encoding components of the plastid transcription and translation apparatus, the energetic apparatus as well as two genes encoding components of the plastid protease and acetyl-CoA carboxylase, showed maximum transcript accumulation at the 2-day stage (Cluster IIA and IIB). Finally, the genes encoding components of the photosynthetic apparatus of Cluster III reached maximum transcript abundance in later stages of chloroplast development. This coordinated expression of plastid genes reflects the presence of regulatory mechanisms that modulate plastid gene expression in different plant tissues and developmental stages. We identified an Arabidopsis mutant, rpoZ191, in which a T-DNA is inserted in the RpoT;3 gene encoding the plastid-targeted phage-type NEP enzyme. The mutant displays a general reduction in growth, as well as a delay in greening and in chloroplast development. Real-time PCR analysis of plastid RNA accumulation showed that the RpoT;3 mutation caused a significant decrease in plastid transcript accumulation at the 2-day stage and a smaller inhibition at the 5-day stage. No major effects of the RpoT;3 mutation on the accumulation of plastid transcripts was observed in mature seeds and 5-day roots. Additionally, plastid transcript accumulation in mutant siliques was not significantly different from the wild-type, except for trnfM-CAU and trnW-CCA, which showed enhanced transcript levels. Taken together, these data indicate that the RpoT;3 NEP enzyme plays an important role in the overall transcription of plastid genes during the early phases of chloroplast and leaf differentiation. Furthermore, a functional RpoT;3 is required for the activation of selected nucleus-encoded plastid-localized proteins. However, the enhanced activity of RpoT;3 during the early stages of chloroplast differentiation is not due to an increase in RpoT;3 mRNA abundance. We suggest that post-transcriptional mechanisms (e.g. phosphorylation, specificity factors) activate the transcription of plastid RpoT;3 - transcribed genes during the early stages of plastid development.
2

The role of RpoT;3 in chloroplast development and gene expression

Chandler, Aglaia 02 June 2009 (has links)
The real-time PCR assay method was used to quantify the RNA abundance of twenty-eight plastid genes in a range of tissues and developmental stages of Arabidopsis thaliana. Three groups of co-regulated genes were identified. Three trn genes (Cluster I) showed differential expression in siliques. Genes encoding components of the plastid transcription and translation apparatus, the energetic apparatus as well as two genes encoding components of the plastid protease and acetyl-CoA carboxylase, showed maximum transcript accumulation at the 2-day stage (Cluster IIA and IIB). Finally, the genes encoding components of the photosynthetic apparatus of Cluster III reached maximum transcript abundance in later stages of chloroplast development. This coordinated expression of plastid genes reflects the presence of regulatory mechanisms that modulate plastid gene expression in different plant tissues and developmental stages. We identified an Arabidopsis mutant, rpoZ191, in which a T-DNA is inserted in the RpoT;3 gene encoding the plastid-targeted phage-type NEP enzyme. The mutant displays a general reduction in growth, as well as a delay in greening and in chloroplast development. Real-time PCR analysis of plastid RNA accumulation showed that the RpoT;3 mutation caused a significant decrease in plastid transcript accumulation at the 2-day stage and a smaller inhibition at the 5-day stage. No major effects of the RpoT;3 mutation on the accumulation of plastid transcripts was observed in mature seeds and 5-day roots. Additionally, plastid transcript accumulation in mutant siliques was not significantly different from the wild-type, except for trnfM-CAU and trnW-CCA, which showed enhanced transcript levels. Taken together, these data indicate that the RpoT;3 NEP enzyme plays an important role in the overall transcription of plastid genes during the early phases of chloroplast and leaf differentiation. Furthermore, a functional RpoT;3 is required for the activation of selected nucleus-encoded plastid-localized proteins. However, the enhanced activity of RpoT;3 during the early stages of chloroplast differentiation is not due to an increase in RpoT;3 mRNA abundance. We suggest that post-transcriptional mechanisms (e.g. phosphorylation, specificity factors) activate the transcription of plastid RpoT;3 - transcribed genes during the early stages of plastid development.
3

Un micro-bolomètre supraconducteur: de la conception à l'utilisation au laboratoire

Graveline, Jonathan January 2016 (has links)
Pour augmenter sa compréhension du monde qui l’entoure, le physicien moderne ne cesse de travailler au développement d’outils théoriques ou expérimentaux pour l’aider à répondre à ses questions fondamentales. Une partie de ces chercheurs tente de répondre à une question bien définie, mais simultanément très vague : qu’est-ce que le bruit électro- nique? Guidés par cette idée, certains étudient des dispositifs comme la jonction tunnel ou la jonction Josephson, alors que d’autres travaillent à l’amélioration des méthodes de détection du bruit. Le présent mémoire de maîtrise traite donc de la conception d’un outil de détection bien particulier, le micro-bolomètre supraconducteur de niobium-titane-niobium. La théorie derrière le fonctionnement d’un tel dispositif est expliquée à l’aide d’une comparaison entre un bolomètre conventionnel et un bolomètre supraconducteur. Des concepts comme la sensibilité d’un détecteur, la conductance thermique et la méthode d’utilisation sont présentés. Les étapes du procédé de fabrication sont ensuite explicitées dans les moindres détails. Finalement, les propriétés électroniques d’un tel micro-bolomètre sont analysées à l’aide de la courbe caractéristique courant-tension, de la courbe de transition supraconductrice en température et de dfférentes mesures en réflectométrie. La puissance équivalente de bruit (NEP) mesurée est de l’ordre de 10[indice supérieur −17] W/√Hz et le temps caractéristique de détection est de 1.43 μs. Le dispositif présenté dans ce mémoire a un avantage important par rapport aux bolomètres supraconducteurs généralement utilisés : il ne nécessite pas de courant de polarisation continu pour le mettre en fonctionnement. Ceci peut résulter en divers avantages technologiques.
4

The role of cell-surface neutral metalloendopeptidases in craniofacial development

Spencer-Dene, Bradley January 1995 (has links)
No description available.
5

Productivity of Montane Meadows in a Warming World: Evidence from an Elevation Gradient and a Warming Experiment

Henderson, Amanda, Henderson, Amanda January 2016 (has links)
Climate change is expected to disproportionately impact high elevation ecosystems by disrupting current temperature and precipitation regimes. The future carbon balance of these systems is uncertain, given the interplay between longer growing season length and the potential for increased drought. Currently, the most robust inferences about ecosystem responses to changing climate come from the integration of experimental and observational methods. In this thesis, I utilize evidence from a warming experiment and an elevational gradient to gain insights into how aspects of ecosystem productivity and community functional composition change in response to the abiotic environment. First, I show that ecosystem productivity was similar in the heated and ambient treatment groups of the warming experiment. Net ecosystem productivity (NEP) was similar between treatments with only slightly increased NEP in the early season in the heated treatment. Important leaf functional traits (leaf mass per area, LMA; leaf dry matter content, LDMC) shifted with heating in directions associated with higher productivity, both at the community level and within species. While these results are counterintuitive, potential insight was provided by a soil cooling effect found in the heated plots in the early season. Second, I investigate ecosystem productivity across spatial and temporal gradients using phenology cameras. I show strong relationships between greenness indices generated from camera images and on-the-ground measurements of gross primary productivity (GPP). I also used changes in greenness indices early season to infer green-up rates, and found a strong pattern of increasing green-up rate with increasing elevation. Together, these studies highlight the importance of comparing experimental and gradient methods to assess how different spatial and temporal scales influence our conclusions about the effect of climate change on ecosystems.
6

A critique of the Marxist theory of social evolution with particular reference to Erik Molnar's A Magyar nep ostortenete

Hamori-Torok, Charles January 1960 (has links)
This paper intends to show the application of the Marxist theory of social evolution to the reconstruction of Magyar proto-history and it examines critically this application. E. Molnar, a Hungarian Marxist proto-historian, published a book under the title A Magyar Nep Ostortenete (proto-History of the Magyar People). This work is shown to represent a Marxist response to the ideological importance of proto-historical studies in Hungary. The argument developed in this paper is as follows: 1. The study of proto-history has been important in Hungary scientifically as well as ideologically. Molnar's attempted reconstruction of Magyar proto-history is a most important Marxist response to the scientific and ideological importance of Hungarian proto-historical studies. 2. The application of this Marxist theory of social evolution makes for bad anthropological theory. Molnar is forced by his Marxist persuasion to look for traces of proto-Communistic social organization in the proto-history of the Magyars, and his attempt to do so results in the formulation of some hypotheses that are not borne out by available evidence. 3. American anthropology is not a unified, and codified set of officially endorsed theories as Molnar implies. Even among American evolutionist anthropologists one finds significant differences in approach and emphasis. At the same time, some aspects of American evolutionist anthropology are seen as capable of providing better ways of approaching the problem of proto-historical reconstruction than Molnar's own Marxist doctrine. Molnar's argument is presented in some detail in this paper. His arguments are outlined and commented upon. His linguistic, physical anthropological, archeological and ethnographic material is discussed and interpreted, and his dependence upon Engels and Soviet anthropologists is indicated. The final conclusion of the paper is that the Marxist theory of social evolution as interpreted by Molnar is based on a set of a priori laws which are not validated by the available evidence. / Arts, Faculty of / Anthropology, Department of / Graduate
7

Estimating the Carbon Fluxes using the CASA Model in the Southern United States

Rongali, Venkata Narendra Appala 01 May 2010 (has links)
A minute change in human body temperature can get one collapsed permanently. If this is the case with human body, one might wonder what would be the case with Earth. The result is the greenhouse. The main function of the greenhouse gases (GHG’s) is to tap energy from the sun and prevent the heat energy escaping to space, thus sustaining life on earth. Because of increased human activity, industrialization, and deforestation, the concentration of the GHG’s in the atmosphere has increased, resulting in a temperature rise. Considering the effects of temperature rise, caused by the GHG’s, one should know the ways to minimize them. In order to do this, an estimation of the amount of GHG’s is important. The CASA model is one such model that estimate the GHG’s and also the amount of carbon in the atmosphere by estimating the Net Ecosystem Productivity (NEP) and Net Primary Productivity (NPP).
8

Effect of hyperglycemia and thiazolidinediones on cardiac angiotensin converting enzyme 2 (ACE2) and neprilysin (NEP) in db/db diabetic mice.

Fadnavis, Rucha 30 August 2017 (has links)
No description available.
9

O dimensionamento da consciência ambiental no ensino da paisagem geográfica: uma pesquisa de intervenção pedagógica com abordagem sistêmica e uso da escala NEP / The dimensioning of environmental awareness in geographic landscape teaching: a pedagogical intervention research with a systemic approach and use of the NEP scale

Lima, Rosana Silvestre de 17 September 2018 (has links)
O desenvolvimento da consciência ambiental no Brasil vem sendo pautado pelos princípios norteadores presentes nos fóruns ambientais mundiais e por seus desdobramentos institucionais através de legislações específicas, tais como o Plano Nacional de Educação Ambiental PNEA (1999) que prevê atribuições às modalidades formais e informais de ensino e os Parâmetros Curriculares Nacionais PCNs (1997) ao inserirem a proposta dos temas transversais, incluindo o meio ambiente, para os níveis fundamental e médio de educação. Mas, mesmo garantindo a penetração social do tema, a presença de legislações específicas tem se mostrado insuficiente para a clareza e efetivação da formação ambiental, o que pode ser observado nas pesquisas sobre o tema que se voltam ao diagnóstico de atitudes ecológicas em detrimento dos processos de aprendizagem. Tendo em vista a necessidade de explicar como ocorrem estes processos dentro da temática ambiental, esta pesquisa teve como objetivo geral dimensionar a consciência ambiental a partir de uma intervenção pedagógica dirigida, tendo por base a teoria da paisagem geográfica de Monteiro (2001) e os referenciais pedagógicos de Vigotski (2012, 2014) e Freire (2004). De forma complementar estabelecemos como objetivo específico produzir e testar a validade de uma proposta intencional de intervenção pedagógica para demonstrar a hipótese de que a abordagem sistêmica da paisagem geográfica (Monteiro, 2001) tem potencial na ampliação da consciência ambiental. O procedimento central da pesquisa caracterizou-se pela experimentação junto a dois grupos de jovens moradores nas proximidades das Áreas de Proteção Ambiental Capivari-Monos/SP e Bororé-Colônia, para os quais se diferenciou a abordagem dos conteúdos de ensino, sendo que um deles participou de aulas dentro da perspectiva sistêmica (MONTEIRO, 2001), e o outro teve os assuntos tratados de forma tópica, sem que fossem enfatizadas as relações entre os conteúdos. A mensuração da consciência ambiental foi realizada a partir de duas variáveis operacionais (VOLPATO, 2015), sendo a primeira qualitativa, avaliando a capacidade explicativa dos estudantes quanto aos fenômenos ambientais estudados, e a segunda, quantitativa, a partir da escala NEP (New Ecological Paradigm) (DUNLAP et al, 2000). A combinação de variáveis qualitativa e quantitativa revelou-se determinante para a maior precisão no dimensionamento da consciência ambiental, e identificação das causas associadas ao seu desenvolvimento dentro das proposições teóricometodológicas estabelecidas pela pesquisa. Outros resultados ficaram a cargo da demonstração de problemas quanto ao nível de alfabetização de jovens frequentadores do sistema público de ensino; da viabilidade de uma proposição curricular na temática ambiental a partir da teoria da paisagem; da diferenciação entre percepção e consciência ambiental; e da avaliação quanto à capacidade de mensuração da escala NEP dentro do estudo proposto. / The development of environmental awareness in Brazil has been guided by the principles present in the global environmental forums and by its effects through specific legislation, such as the National Environmental Education Plan (PNEA) (1999), which provides for attributions to formal and informal teaching and the National Curricular Parameters - PCNs (1997) by inserting the proposal of cross-cutting themes, including the environment, for the fundamental and medium levels of education. These actions guarantee the social penetration of the theme, however the presence of specific legislation has proved insufficient for the clarity and effectiveness of the environmental education, which can be observed in the researches on diagnostics of ecological attitudes to the detriment of the processes of learning. Considering the need to explain how these processes occur within the environmental theme, this research had the general objective to dimension environmental awareness through on a guided pedagogical intervention, based on Monteiro\'s (2001) geographical landscape theory and the pedagogical references of Vigotski (2012, 2014) and Freire (2004). In a complementary way, we established as a specific objective to produce and test the validity of an intentional model of pedagogical intervention to demonstrate the hypothesis that the systemic approach of the geographic landscape (Monteiro, 2001) has the potential to increase environmental awareness. The central procedure of the research was characterized by the experimentation with two groups of young residents near of the Capivari-Monos / SP and Bororé-Colônia Environmental Protection Areas, for which the approach to teaching contents was differentiated, one of which participated of classes within the systemic perspective (MONTEIRO, 2001), and the other had the subjects treated topically, without emphasizing the relations between contents. The measurement of environmental awareness was made using two operational variables (VOLPATO, 2015). The first one was qualitative, assessing the ability of students to explain the environmental phenomena studied, and the second, quantitative, from the NEP scale (New Ecological Paradigm) (DUNLAP et al, 2000). The combination of qualitative and quantitative variables was determinant for the greater precision in the dimensioning of environmental awareness, and identification of the causes associated with its development within the theoreticalmethodological propositions established by the research. We highlight other results as the demonstration of problems regarding the level of literacy of young people served by the public school system; the feasibility of a curricular proposition in the environmental theme from the landscape theory; the differentiation between perception and environmental awareness; and the evaluation of the measurement capacity of the NEP scale within the proposed study.
10

O dimensionamento da consciência ambiental no ensino da paisagem geográfica: uma pesquisa de intervenção pedagógica com abordagem sistêmica e uso da escala NEP / The dimensioning of environmental awareness in geographic landscape teaching: a pedagogical intervention research with a systemic approach and use of the NEP scale

Rosana Silvestre de Lima 17 September 2018 (has links)
O desenvolvimento da consciência ambiental no Brasil vem sendo pautado pelos princípios norteadores presentes nos fóruns ambientais mundiais e por seus desdobramentos institucionais através de legislações específicas, tais como o Plano Nacional de Educação Ambiental PNEA (1999) que prevê atribuições às modalidades formais e informais de ensino e os Parâmetros Curriculares Nacionais PCNs (1997) ao inserirem a proposta dos temas transversais, incluindo o meio ambiente, para os níveis fundamental e médio de educação. Mas, mesmo garantindo a penetração social do tema, a presença de legislações específicas tem se mostrado insuficiente para a clareza e efetivação da formação ambiental, o que pode ser observado nas pesquisas sobre o tema que se voltam ao diagnóstico de atitudes ecológicas em detrimento dos processos de aprendizagem. Tendo em vista a necessidade de explicar como ocorrem estes processos dentro da temática ambiental, esta pesquisa teve como objetivo geral dimensionar a consciência ambiental a partir de uma intervenção pedagógica dirigida, tendo por base a teoria da paisagem geográfica de Monteiro (2001) e os referenciais pedagógicos de Vigotski (2012, 2014) e Freire (2004). De forma complementar estabelecemos como objetivo específico produzir e testar a validade de uma proposta intencional de intervenção pedagógica para demonstrar a hipótese de que a abordagem sistêmica da paisagem geográfica (Monteiro, 2001) tem potencial na ampliação da consciência ambiental. O procedimento central da pesquisa caracterizou-se pela experimentação junto a dois grupos de jovens moradores nas proximidades das Áreas de Proteção Ambiental Capivari-Monos/SP e Bororé-Colônia, para os quais se diferenciou a abordagem dos conteúdos de ensino, sendo que um deles participou de aulas dentro da perspectiva sistêmica (MONTEIRO, 2001), e o outro teve os assuntos tratados de forma tópica, sem que fossem enfatizadas as relações entre os conteúdos. A mensuração da consciência ambiental foi realizada a partir de duas variáveis operacionais (VOLPATO, 2015), sendo a primeira qualitativa, avaliando a capacidade explicativa dos estudantes quanto aos fenômenos ambientais estudados, e a segunda, quantitativa, a partir da escala NEP (New Ecological Paradigm) (DUNLAP et al, 2000). A combinação de variáveis qualitativa e quantitativa revelou-se determinante para a maior precisão no dimensionamento da consciência ambiental, e identificação das causas associadas ao seu desenvolvimento dentro das proposições teóricometodológicas estabelecidas pela pesquisa. Outros resultados ficaram a cargo da demonstração de problemas quanto ao nível de alfabetização de jovens frequentadores do sistema público de ensino; da viabilidade de uma proposição curricular na temática ambiental a partir da teoria da paisagem; da diferenciação entre percepção e consciência ambiental; e da avaliação quanto à capacidade de mensuração da escala NEP dentro do estudo proposto. / The development of environmental awareness in Brazil has been guided by the principles present in the global environmental forums and by its effects through specific legislation, such as the National Environmental Education Plan (PNEA) (1999), which provides for attributions to formal and informal teaching and the National Curricular Parameters - PCNs (1997) by inserting the proposal of cross-cutting themes, including the environment, for the fundamental and medium levels of education. These actions guarantee the social penetration of the theme, however the presence of specific legislation has proved insufficient for the clarity and effectiveness of the environmental education, which can be observed in the researches on diagnostics of ecological attitudes to the detriment of the processes of learning. Considering the need to explain how these processes occur within the environmental theme, this research had the general objective to dimension environmental awareness through on a guided pedagogical intervention, based on Monteiro\'s (2001) geographical landscape theory and the pedagogical references of Vigotski (2012, 2014) and Freire (2004). In a complementary way, we established as a specific objective to produce and test the validity of an intentional model of pedagogical intervention to demonstrate the hypothesis that the systemic approach of the geographic landscape (Monteiro, 2001) has the potential to increase environmental awareness. The central procedure of the research was characterized by the experimentation with two groups of young residents near of the Capivari-Monos / SP and Bororé-Colônia Environmental Protection Areas, for which the approach to teaching contents was differentiated, one of which participated of classes within the systemic perspective (MONTEIRO, 2001), and the other had the subjects treated topically, without emphasizing the relations between contents. The measurement of environmental awareness was made using two operational variables (VOLPATO, 2015). The first one was qualitative, assessing the ability of students to explain the environmental phenomena studied, and the second, quantitative, from the NEP scale (New Ecological Paradigm) (DUNLAP et al, 2000). The combination of qualitative and quantitative variables was determinant for the greater precision in the dimensioning of environmental awareness, and identification of the causes associated with its development within the theoreticalmethodological propositions established by the research. We highlight other results as the demonstration of problems regarding the level of literacy of young people served by the public school system; the feasibility of a curricular proposition in the environmental theme from the landscape theory; the differentiation between perception and environmental awareness; and the evaluation of the measurement capacity of the NEP scale within the proposed study.

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