京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19895号 / 工博第4211号 / 新制||工||1651(附属図書館) / 32972 / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 吉田 潤一, 教授 松田 建児, 教授 松原 誠二郎 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24432号 / 理博第4931号 / 新制||理||1704(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 依光 英樹, 教授 若宮 淳志, 教授 畠山 琢次 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Made available in DSpace on 2016-01-26T18:56:28Z (GMT). No. of bitstreams: 1 Anderson Guerra.pdf: 329117 bytes, checksum: 77c026179d903be26ade93dd0fc35017 (MD5) Previous issue date: 2013-08-28 / The temperature is considered either as a limiting factor stimulating factor for photosynthesis. The reduction of photosynthetic potential, and consequently the growth of the plant can be linked to several physiological factors. The aim of this study was to evaluate the effect of temperature on photosynthesis and growth of the stem of cane sugar in its initial phase. The experiment was conducted at UNOESTE located in Presidente Prudente - SP, during the period November 2011 to April 2012 in climatic chambers with phytotron type constant control of temperature, photoperiod and irradiation. The experimental design was a completely randomized design (CRD), studying the early development of cane sugar in three temperature regimes: low temperature (19 ° C day and 13 ° C night), average temperatures (29 ° C day and 23 ° C night); high temperatures (33 ° C day and 27 ° C night) with eight replicates for each treatment. The plots consisted of plastic pots with a capacity of 12 kg of soil, containing a culm of cane sugar. Seedlings of cane sugar developed in a controlled environment for five months with daily irrigation and maintained under field capacity. Evaluations consisted of chlorophyll fluorescence, photosynthetic potential through the curve A / Ci, daily balancing of CO2, the height, diameter and stem dry matter. The regime of low temperatures was more harmful to the initial growth of cane sugar than the regime with high temperatures. Low temperatures negatively affected photosynthetic rates by reducing the efficiency of photosynthetic enzymes and damages caused by the photosynthetic apparatus, thereby reducing the initial growth of the stem of cane sugar. At low temperatures, the stalk of cane sugar had lower dry matter, and also less growth in height of stem. / A temperatura é considerada tanto um fator limitante como um fator estimulante para a fotossíntese. A redução do potencial fotossintético e consequentemente do crescimento da planta pode estar ligada a diversos fatores fisiológicos. O objetivo deste estudo foi avaliar o efeito da temperatura sobre a fotossíntese e o crescimento do colmo da cana-de-açúcar em sua fase inicial. O experimento foi conduzido na UNOESTE situada em Presidente Prudente SP, durante o período de Novembro de 2011 a Abril de 2012, em câmara climatizada tipo fitotron com controle constante de temperatura, fotoperíodo e irradiação. O delineamento experimental adotado foi o inteiramente casualizado (DIC), estudando-se o desenvolvimento inicial da cana-de-açúcar em três regimes de temperatura: temperaturas baixas (19ºC diurna e 13ºC noturna); temperaturas médias (29ºC diurna e 23ºC noturna); temperaturas altas (33ºC diurna e 27ºC noturna), tendo para cada tratamento oito repetições. As parcelas experimentais foram constituídas por vasos plásticos com capacidade para 12 kg de solo, contendo um colmo de cana-de-açúcar. As mudas de cana-de-açúcar se desenvolveram nesse ambiente controlado durante cinco meses com irrigação diária e mantidas sob capacidade de campo. As avaliações consistiram de fluorescência da clorofila a, potencial fotossintético através da curva A/Ci, balanço diário de CO2, a altura, o diâmetro e a matéria seca do colmo. O regime de baixas temperaturas foi mais prejudicial ao crescimento inicial da cana-de-açúcar do que o regime com altas temperaturas. As baixas temperaturas afetaram negativamente as taxas fotossintéticas através da redução da eficiência das enzimas fotossintéticas e pelos danos gerados no aparato fotossintético, diminuindo, portanto, o crescimento inicial do colmo da cana-de-açúcar. Em baixas temperaturas, o colmo da cana-de-açúcar teve menor matéria seca, e também menor crescimento em altura de colmo.

Made available in DSpace on 2016-07-18T17:51:11Z (GMT). No. of bitstreams: 1 Anderson Guerra.pdf: 329117 bytes, checksum: 77c026179d903be26ade93dd0fc35017 (MD5) Previous issue date: 2013-08-28 / The temperature is considered either as a limiting factor stimulating factor for photosynthesis. The reduction of photosynthetic potential, and consequently the growth of the plant can be linked to several physiological factors. The aim of this study was to evaluate the effect of temperature on photosynthesis and growth of the stem of cane sugar in its initial phase. The experiment was conducted at UNOESTE located in Presidente Prudente - SP, during the period November 2011 to April 2012 in climatic chambers with phytotron type constant control of temperature, photoperiod and irradiation. The experimental design was a completely randomized design (CRD), studying the early development of cane sugar in three temperature regimes: low temperature (19 ° C day and 13 ° C night), average temperatures (29 ° C day and 23 ° C night); high temperatures (33 ° C day and 27 ° C night) with eight replicates for each treatment. The plots consisted of plastic pots with a capacity of 12 kg of soil, containing a culm of cane sugar. Seedlings of cane sugar developed in a controlled environment for five months with daily irrigation and maintained under field capacity. Evaluations consisted of chlorophyll fluorescence, photosynthetic potential through the curve A / Ci, daily balancing of CO2, the height, diameter and stem dry matter. The regime of low temperatures was more harmful to the initial growth of cane sugar than the regime with high temperatures. Low temperatures negatively affected photosynthetic rates by reducing the efficiency of photosynthetic enzymes and damages caused by the photosynthetic apparatus, thereby reducing the initial growth of the stem of cane sugar. At low temperatures, the stalk of cane sugar had lower dry matter, and also less growth in height of stem. / A temperatura é considerada tanto um fator limitante como um fator estimulante para a fotossíntese. A redução do potencial fotossintético e consequentemente do crescimento da planta pode estar ligada a diversos fatores fisiológicos. O objetivo deste estudo foi avaliar o efeito da temperatura sobre a fotossíntese e o crescimento do colmo da cana-de-açúcar em sua fase inicial. O experimento foi conduzido na UNOESTE situada em Presidente Prudente SP, durante o período de Novembro de 2011 a Abril de 2012, em câmara climatizada tipo fitotron com controle constante de temperatura, fotoperíodo e irradiação. O delineamento experimental adotado foi o inteiramente casualizado (DIC), estudando-se o desenvolvimento inicial da cana-de-açúcar em três regimes de temperatura: temperaturas baixas (19ºC diurna e 13ºC noturna); temperaturas médias (29ºC diurna e 23ºC noturna); temperaturas altas (33ºC diurna e 27ºC noturna), tendo para cada tratamento oito repetições. As parcelas experimentais foram constituídas por vasos plásticos com capacidade para 12 kg de solo, contendo um colmo de cana-de-açúcar. As mudas de cana-de-açúcar se desenvolveram nesse ambiente controlado durante cinco meses com irrigação diária e mantidas sob capacidade de campo. As avaliações consistiram de fluorescência da clorofila a, potencial fotossintético através da curva A/Ci, balanço diário de CO2, a altura, o diâmetro e a matéria seca do colmo. O regime de baixas temperaturas foi mais prejudicial ao crescimento inicial da cana-de-açúcar do que o regime com altas temperaturas. As baixas temperaturas afetaram negativamente as taxas fotossintéticas através da redução da eficiência das enzimas fotossintéticas e pelos danos gerados no aparato fotossintético, diminuindo, portanto, o crescimento inicial do colmo da cana-de-açúcar. Em baixas temperaturas, o colmo da cana-de-açúcar teve menor matéria seca, e também menor crescimento em altura de colmo.

La réduction du CO₂ est considérée comme une des approches les plus intéressantes pour convertir ce gaz en produits chimique d’intérêt tels que les acides carboxyliques. Le marché de ces composés devrait augmenter considérablement au cours des prochaines années, d'où la nécessité de trouver des méthodes de production durables et respectueuses de l'environnement. Les complexes de samarium divalents sont reconnus pour leur fort pouvoir réducteur monoélectronique, ce qui en fait des réactifs de choix pour la réduction de certains groupes fonctionnels difficiles à réduire tels que le CO₂. Cependant, dans la littérature, bien que ce réactif ait été utilisé en association avec le CO₂, prouvant ainsi que la réduction du CO₂ est possible, mais jamais à notre connaissance pour des applications synthétiques. Nous rapportons ici l'activation du CO₂ initiée par le samarium bivalent électrogénéré. Grâce à notre méthode, récemment mise au point, pour la production électrochimique in situ d’espèces divalentes de samarium, la synthèse de dérivés de l’acide benzoïque a été réalisée avec succès. De plus, les conditions d'activation électrocatalytique du CO₂ ont été établies dans ce travail et appliquées non seulement à la préparation des acides phénylacétiques à partir de dérivés du chlorure de benzyle, mais également à l'hydrocarboxylation régiosélective des analogues du styrène et du phénylacétylène. Ce protocole à base de Sm (II) électrogénéré offre la prochaine génération de systèmes durables pour la transformation du CO₂ en molécules de haute valeur sous des conditions douces et sans l'ajout de co-réducteurs. / CO₂ activation is considered one of the most attractive tools to convert this cheap, abundant and non-toxic gas into valuable chemical feedstocks such as carboxylic acids. The market value of these compounds is expecting a significant increase in the next few years, thus the urgent need for sustainable and eco-friendly production pathways. Divalent samarium complexes are known for their strong monoelectronic reductive power that made them the perfect choice for the reduction of some challenging functional groups. Indeed, in the literature, this reagent has been used in combination with CO₂ but only to achieve the reductive disproportionation of CO₂ while no example reported C-C bond formation via CO₂ activation using the Sm(II) complexes. Herein, we report the CO₂ activation initiated by electrogenerated divalent samarium. Taking advantage of our recently developed method for the in situ generation of Sm(II) species, the synthesis of benzoic acid derivatives was successfully achieved. Furthermore, electrocatalytic CO₂ activation conditions were established in this work and applied not only for the preparation of phenylacetic acids from benzyl chloride derivatives but also for the regioselective hydrocarboxylation of styrene and phenylacetylene analogs. This electrochemical Sm(II)-based protocol offers the next generation of sustainable system to transform CO₂ into highly valued molecules under mild conditions and without the addition of co-reductants.

No description available.

Les changements climatiques sont susceptibles d’affecter la croissance, le développement et la régénération des pessières noires de la forêt boréale. Les échecs de régénération dans les pessières à mousses (PM) de l’ouest du Québec causent des trouées dans la mosaïque forestière dense et augmentent la proportion de pessières à lichens (PL) dans le paysage. Les objectifs de l’étude sont de déterminer si les caractéristiques contrastantes des PM et des PL engendrent différents taux de photosynthèse maximale (Amax) chez les épinettes noires sur un gradient latitudinal ou saisonnier. Ensuite, l’étude tentera de déterminer si le Amax des individus reflète leurs capacités physiologiques par leur taux de carboxylation maximal (Vcmax) et de transport des électrons maximal (Jmax) extraits de courbes de réponse au CO2. Les taux de Vcmax et Jmax sont différents entre les PM et les PL car l’acquisition de ces nutriments semble différente. La latitude influence les valeurs de Vcmax et Jmax, mais l’effet serait causé par les caractéristiques floristiques et la composition du sol des placettes plutôt que par la latitude. Les capacités physiologiques ne se reflètent pas dans les valeurs de Amax, autant pour le type de peuplement que la latitude, car Amax serait limité par la concentration en CO2 qui ne permet pas la saturation de l’enzyme rubisco. Malgré l’absence de différence entre le Amax des PM et des PL, l’augmentation de la concentration en CO2 et de la température risque de créer un écart de Amax entre les types de peuplement, considérant leurs capacités physiologiques différentes. / Climate change is likely to affect the growth, development and regeneration of black spruce stands across the boreal forest. Regeneration failures cause gaps in the dense black spruce-feathermoss (BSFM) mosaic increasing the landscape proportion of open lichen-woodland (LW). The aims of the study are to determine whether the contrasting characteristics of BSFM and LW induce different light-saturated maximum photosynthesis (Amax) in black spruce trees across a latitudinal or seasonal gradient. Then the study will attempt to determine if Amax is likely to reflect their physiological capacities based on their maximum carboxylation rate (Vcmax) and maximum electron transport rate (Jmax) derived from CO2 response curves. Vcmax and Jmax are different between BSFM and LW mainly because nutrient acquisition seems different between stand types. Latitude affects values of Vcmax and Jmax, but the effect could be explained by soil and vegetation composition between experimental plots rather than by latitude. Physiological capacities do not match Amax values for stand type and latitude because Amax would be limited by CO2 concentration which does not allow saturation of rubisco. Despite the lack of difference between the Amax of BSFM and LW stands, future increase in CO2 concentration and temperature could induce a gap between their respective photosynthesis rates because of their different physiological capacities.

No description available.

Mitochondrial isocitrate dehydrogenase 2 (IDH2) catalyzes reductive carboxylation (RC, reverse Krebs cycle pathway) and 2HG synthesis (2HG) - metabolite of which many scientists are interested. 2HG may be concurrently synthetized in cytosol by IDH1. RC is involved in anabolic reactions necessary for cell proliferation - produces citrate, fatty acid precursor - especially in hypoxia. IDH2 and IDH1 are not the only enzymes that are involved in 2HG synthesis. Recently, several enzymes, which participate in 2HG production, have been discovered. 2HG is useful in cancer diagnostics due to its overproduction by transformed cells. Moreover, 2HG may cause epigenetic changes via inhibition of 2-oxoglutarate dependent dioxygenase. In this work, the importance of RC and 2HG synthesis in cancer and healthy cells was investigated by gas chromatography with mass spectrometry detection as well as IDH2 influence. We found that IDH2 significantly participates in reverse RC and 2HG synthesis in breast cancer cell lines and uses glutaminolysis as a supplementary anaplerotic pathway. RC is increased by hypoxia, inhibition of respiration, and decreased by activation of respiration or hypocapnia. We confirmed 2HG synthesis and RC in healthy cells (fibroblasts, breast epithelial cells etc.) as well as in cancer cells....