Dissertations / Theses on the topic 'Rubicon'

What are the impediments to and stimuluses for transitions from violent civil conflict to peace? This dissertation investigates factors that influence civil conflict resolution. There are four key findings. First, democratisation reforms are likely to prompt peace talks with rebel groups. There are costs associated with recognising internal armed challengers as legitimate bargaining partners that deter governments from initiating peace talks. Democratic reform periods provide a window of opportunity for peace negotiations because factors that make institutional reform more likely also encourage peaceful resolution of conflict. The emergence of democratic institu- tions changes the state preferences by increasing the influence of the median citizen vis-`a-vis the authoritarian elite. Second, fragmented conflicts are harder to resolve because they are likely to be over a multidimensional issue space. Multiparty decision making that involves two or more salient issues are likely to have cyclic collective preferences, which render armed conflict a viable instrument for pursuing political goals. Third, involvement of the United Nations (UN) mitigates the adverse impact of conflict fragmentation over peaceful resolution. UN involvement changes the incentives and opportunities of actors to founder a possible bargain. The UN fa- cilitates a path-dependent peace process and brings institutions that induce an equilibrium by overcoming the problems that arise due to cyclic collective preferences. Finally, the military manpower supply system of a state influences its civil conflict processes. How a state recruits rank-and-file members of the military forces is a central institutional arrangement that influences the incentives and opportunities of relevant actors. Compared to all-volunteer forces (AVFs), conscription is an impediment to conflict termination because the cost some individuals incur by being subject to conscription decreases the opportunity cost of rebellion, increases grievances and insulates influential sections of the population from the cost of conflict. As a result, conflict termination becomes less likely.

Made available in DSpace on 2016-04-28T19:34:24Z (GMT). No. of bitstreams: 1 Elias Nascimento.pdf: 94720526 bytes, checksum: 5d9e140975a2ba8884c72826cf3db0cb (MD5) Previous issue date: 2008-04-23
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The objective of this dissertation is the study of the linguistic-discursive strategies of the laughable in Porque Lulu Bergatim não atravessou o Rubicon of José Cândido de Carvalho. The author s work presents dozens of curious stories on the interior of the country. Written in a very characteristic way, the narratives introduce funny personages involved in unusual situations. The author's style is marked, mainly, by the use of the comic exaggeration employed in ironies and metaphors. The present study included the analysis of stories, their connection with the laughter and the brevity inherent to both. In the present work the manifestation of the laughter was analyzed considering the concepts discussed by the philosophers and theoretical from the Antiquity to the current days. In the study it was verified that in the last centuries the comedian was own of the inferior classes, lowered, with addictions and faults. Starting from the century XX the laughter began to have value in the social relationships. In the contemporary theories, the laughter exists to correct habits, to punish behaviors and to punish distracted, and it can be expressed in four ways: in the forms and movements, in the situations, in the words and in the character. The corpus was divided considering these four categories. The analysis of the linguistic-discursive strategies of the laughter detached the polissemic exploration happened in the stories not only by the use of the metaphors and of the ironies, but also by the use of slangs, of alliterations, of hyperboles, of puns, of strange names and of neologisms
O objetivo desta dissertação é estudar as estratégias lingüístico-discursivas do risível em Porque Lulu Bergatim não atravessou o Rubicon de José Cândido de Carvalho. A obra reúne dezenas de contos curiosos sobre o interior do país. Escritas de forma bastante característica, as narrativas apresentam personagens divertidos envolvidos em situações insólitas. O estilo do autor é marcado, principalmente, pelo uso do exagero cômico empregado às ironias e às metáforas. O estudo abrangeu o gênero conto, sua ligação com o riso e o laconismo inerente a ambos. Compreendeu a manifestação do riso a partir de um levantamento histórico que considerou os conceitos discutidos pelos filósofos e teóricos desde a Antiguidade até os dias atuais. Nesse estudo verificou-se que nos séculos passados o cômico era próprio das classes inferiores, rebaixadas, com vícios e falhas. A partir do século XX o riso passou a ter valor nas relações sociais. Nas teorias contemporâneas, o riso existe para corrigir costumes, castigar comportamentos e punir distraídos, e pode se manifestar de quatro maneiras: nas formas e movimentos, nas situações, nas palavras e no caráter. O corpus foi dividido segundo estas quatro categorias. A análise das estratégias lingüístico-discursivas do riso destacou a exploração polissêmica ocorrida nos contos não só pela utilização das metáforas e das ironias, mas também pelo uso de gírias, de aliterações, de hipérboles, de trocadilhos, de nomes estranhos e de neologismos

Atmospheric CO2 fixation is catalysed by the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Despite the critical role Rubisco plays in the biosphere, it is a slow catalyst that poorly discriminates between substrate CO2 and O2, and is often the rate-limiting step of photosynthesis. These deficiencies have made improving Rubisco function a major target in steps towards enhancing leaf photosynthesis rate and plant growth. In pursuing this goal, one strategy is to identify solutions for improving the kinetics of plant Rubisco and introduce these altered Rubisco isoforms into crops (Sharwood, 2017). Unfortunately efforts to improve the performance of plant Rubiscos have so far proven unsuccessful. Success appears to be hindered by Rubisco’s complex catalytic mechanism and the extensive array of accessory proteins needed to assemble the eight large (L) and eight small (S) subunits into a L8S8 complex and to maintain it in a functional form. The complex catalytic chemistry of Rubisco is prone to inhibition by various sugar-phosphate ligands. These include catalytic misfire products as well as its own substrate, ribulose-1,5-bisphosphate (RuBP), which forms an inactive Rubisco-RuBP (ER) complex when bound to non-carbamylated (i.e. non-activated) catalytic sites. Release of these inhibitors is mediated by the AAA+ (ATPases associated with a variety of cellular activities) protein Rubisco activase (Rca); a Rubisco-specific metabolic repair chaperone for which there are convergently evolved structural isoforms found in most photosynthetic organisms (Bhat et al., 2017a; Mueller-Cajar, 2017). Rca is now also a promising target for manipulating photosynthetic performance, especially under elevated temperature stress and fluctuating light (Carmo-Silva & Salvucci, 2013; Kumar et al., 2009; Kurek et al., 2007; Scafaro et al., 2016; Yamori et al., 2012). Critical to future Rubisco and Rca engineering efforts in plants is a greater mechanistic understanding of how Rca interacts with Rubisco, and the extent to which the kinetics of Rca differ between plant species. Utilising chloroplast transformation in tobacco, this thesis investigated the H9 helix and N-terminal region of Rca, and the βC-βD loop and C terminus of the Rubisco large (L-) subunit (RbcL) to determine their role in the Rubisco-Rca interaction in plants using both in vivo and in vitro methods. Capitalising on the regulatory incompatibility between Rubisco and Rca enzymes from Solanaceae and non-Solanaceae species, this thesis examined how mutations in the tobacco (Solanaceae) and Flaveria (F. bidentis and F. floridana, non-Solanaceae) enzymes influenced their kinetic properties and the Rca activation potential for inhibited ER complexes. The ability to continuously monitor the rate of ER activation provided by a NADH-coupled spectrophotometric method made it preferential to the alternative two-step 14CO2-fixation assay method. Optimising the assay conditions, particularly the accurate determination of enzyme concentrations, was crucial for obtaining reproducible kinetic values. Normalising the measurements of ER activation rate relative to the Rca ATPase activity (kcatATP ) proved critical in providing a means to determine the effect the Rca and Rubisco mutations had on interactivity. Using these assay conditions, mutagenic analyses of the Rca H9 helix found residue 317 plays a dominant role in defining the Rubisco selectivity of NtRca, and is critical for functional FbRca. N-terminal domain swapping modifications to NtRca and FbRca revealed amino acids at the junction of the N-terminal extension and the AAA+ module (residues 50 to 85) significantly influenced both kcatATP and the potential to interact with their cognate Rubiscos, but had little influence on altering interaction with the non-native Rubisco. In vivo analysis of Rubisco-Rca interaction was undertaken using tobacco genotypes producing differing tobacco Rubisco or recombinant Flaveria Rubisco mutants generated by chloroplast transformation of the rbcL gene into the plastome. In vitro analysis using purified enzymes uniformly showed residues 89 and 94 of the βC-βD loop of the F. bidentis, F. floridana and tobacco RbcLs influence interaction with Rca. In contrast, in vivo leaf gas exchange measurements of photosynthetic induction in the tobacco genotypes producing mutant RbcL showed mutation of residues 89 and 94 had little to no influence on their capacity to be activated by the endogenous NtRca. Combinatorial in vitro analyses using the range of RbcL and Rca mutants generated in this study were undertaken to better understand their interaction mechanism. It was found the avidity of Rubisco-Rca interactions were primarily defined by residue 94 in RbcL and 317 in Rca, and less so by RbcL residue 89 and Rca residue 320. Mutations to the RbcL C terminus had little influence on plant Rubisco-Rca interactions except when coupled with mutations that disrupted the connection between the RbcL βC-βD loop and the Rca H9 helix. The cumulative effect of the RbcL βC-βD loop and C-terminal modifications on Rubisco-Rca interactivity of these mutants implies involvement of the RbcL C terminus in the activation mechanism of Rca. This thesis showcases a novel approach to study the mechanism of plant Rubisco-Rca interactions by generating mutant Rubisco variants through tobacco plastome transformation. The work highlights large variations in the kinetics of NtRca (Solanaceae) and FbRca (non-Solanaceae) and provides evidence for variations in their Rubisco activation mechanism. For instance, while a D317K substitution in NtRca significantly enhanced its ability to activate Flaveria Rubisco, the reciprocal K317D mutation in FbRca had little impact on improving its capacity to activate tobacco Rubisco. Improving our understanding of the mechanistic differences in plant Rubisco-Rca interactions is critical for future Rubisco engineering endeavours. It is especially relevant in the context of ongoing efforts to transplant more efficient Rubisco variants into leaf chloroplasts where co-transformation with an appropriate Rca may be needed. Potential transgenic strategies for co-engineering compatible Rubisco and Rca isoforms in planta are also discussed.

Tutkielman tarkoitus on selvittää Rubikin kuution matemaattinen esitysmuoto ryhmäteorian keinoin. Tämän matemaattisen esitysmuodon rakentamiselle tarvittavat ryhmäteoreettiset tulokset ja rakenteet määritellään ja todistetaan lähtien perusasioista, kuten ryhmän ja aliryhmän määritelmistä, aliryhmyysehdoista, Lagrangen lauseesta jne. Ryhmille olennaisten ja perustavanlaatuisten tulosten jälkeen esitetään yksi olennaisimmista käsitteistä; permutaatio, sekä siihen liittyviä tuloksia ja käsitteitä, kuten symmetrinen ryhmä ja pariteetti. Tutkielma etenee ryhmien rakenneyhtäläisyyden, eli homomorfismin käsitteeseen, jota edelleen käytetään edellä määriteltyjen käsitteiden tärkeiden tulosten todistamiseen, kuten esimerkiksi siihen, että pariteettikuvaus on homomorfismi. Lisäksi määritellään rakenneyhtenevyys eli isomorfismi, ja todistetaan tärkeä homomorfismien peruslause, joka yhdistää isomorfismille luonnolliset joukot toisiinsa, jonka avulla Rubikin kuution ryhmän kertaluku saadaan selville. Ryhmien sisäisten operaatioiden ja välisten kuvausten jälkeen siirrytään ryhmien välisiin operaatioihin, joissa rakennetaan kuution ryhmärakenteen esitysmuodolle tarpeelliset käsitteet kuten suora tulo, ryhmän toiminta ja kranssitulo, jossa jokin ryhmä toimii toisen ryhmän suorassa tulossa. Lisäksi näistä rakenteista näytetään esimerkkejä, joiden avulla niiden merkitystä avataan. Näiden ryhmäteoreettisten käsitteiden ja tulosten jälkeen teoriaa käytetään itse Rubikin kuution mallintamiseen, kun ensin määritellään Rubikin kuutiosta erotettavat mallinnettavat osat, kuten palatyypit, ratkaistu kuutio, kääntö ja kombinaatio sekä sen ratkeavuus. Lisäksi tärkeässä osassa ovat permutaatio- ja orientaatiotilat, jotka sisältävät tiedot palojen sijainneista ja asennoista kuutiossa. Ennen kuution syvää käsittelyä osoitetaan yksinkertaisella tavalla ratkeavan Rubikin kuution todella olevan esitettävissä ryhmänä. Ryhmärakenne laajennetaan koskemaan kaikkia kombinaatioita, tarkastelussa, jossa permutaatio- ja orientaatiotilat esitetään aikaisemmin määritellyillä käsitteillä, erityisesti kranssitulolla sekä määriteltävällä ketjutusta vastaavalla operaatiolla. Tämän jälkeen kombinaatioiden joukosta karsitaan pois ne, joita ei voi ratkaista sivujen käännöillä osoittamalla kombinaation ratkeavuusehdot; permutaatiotilojen pariteetin yhtenevyys sekä orientaatiosummien nolla-arvoisuus. Tämän jälkeen ryhmärakenteen esitysmuoto on valmis. Tutkielman lopussa on lyhyt katsaus 2×2×2-kuutioon ja sen yhtäläisyyksiin ja eroavuuksiin verrattuna Rubikin kuutioon, jossa edetään samalla logiikalla kuin Rubikin kuution tarkastelussa.

In this diploma work influence of needle age at Rubisco activity and content in Norway spruce (Picea abies) was studied. The plants were cultivated in conditions with ambient (A) CO2 concentration (350 µmol CO2/mol) and elevated (E) CO2 concentration (700 µmol CO2/mol). Sampling was done two times during the growing season (in the middle of June and in the end of September) were taken. Initial and total Rubisco activities were measured spectrophotometrically. Rubisco content was determined by SDS–PAGE method. Rubisco activity in 18-months-old needles was in E higher than in A. Rubisco contents in current-year needles and one-year-old needles were in A higher than in E in September. These differences were statistically significant that demonstrates the down-regulation of Rubisco content in conditions of elevated CO2 concentration. It seems the course of activities and content depending on age of the needles are antiparallel, that means that decrease of content is followed by increase of activity.

Rubisco activase operates as the chaperone responsible for maintaining the catalytic competency of Ribulose 1,5-bisphophate carboxylase oxygenase (Rubisco) in plants. Rubisco is notoriously inefficient, rapidly self-inactivating under physiological conditions. Rubisco activase uses the power released from the hydrolysis of ATP to power a conformational change in Rubisco, reactivating it. Rubisco activase has been previously shown to form a large range of species in solution; however, little has been done to relate the size of oligomeric species and physiological activity. In this thesis data is presented from a range of biophysical techniques including analytical ultracentrifugation, static light scattering, and small angle X-ray scattering combined with activity assays to show a strong relationship between oligomeric state and activity. The results suggest that small oligomers comprising 2-4 subunits are sufficient to attain full specific activity, a highly unusual property for enzymes from the AAA+ family. Studies utilising a number of Rubisco activase variants enabled the determination of how Rubisco and Rubisco activase may interact within a plant cell. A detailed characterisation of the α-, β-, and a mixture of isoforms further broadened our knowledge on the oligomerisation of Rubisco activase. Of particular importance was the discovery of a thermally stable hexameric Rubisco activase variant. It is hoped that these findings may contribute to development of more heat tolerant Rubisco activase and lead research into more drought resilient crop plants.

Study project (MBA)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: South Africa is a land of contrasts - contrasts in its landscape, cultures and business. Highly successful organisations exist in South Africa. The less fortunate organisations can learn a lot from them and other successful international organisations. Business has become a highly sophisticated science and although a recipe for instant success does not exist, the criteria described in this study can enhance an organisation's chances for success considerably. The first section of the study focuses on a literature study of nine critical factors identified in successful organisations. The study covers: Vision, Map, Customer Focus, Confidence, Standards, Drive, Teamwork, Support and Belonging. The establishment and development of these critical factors within an organisation are fundamental in highly successful organisations. The study will defines and develops these factors into practical and understandable criteria to be used and measured in an organisation. It further uses the criteria to show where an organisation could be failing and highlights some common mistakes that can be avoided. The study also provides business models to develop these criteria. The second section of the study focuses on an internal survey done at Rubico (Pty) Ltd, to measure the criteria explained in the first section. The survey highlights areas where Rubico (Pty) Ltd is functioning well, but also identifies shortcomings. The survey can be used as a measuring tool to provide insight into areas where an organisation is lacking and give the user the ability to manage more effectively.
AFRIKAANSE OPSOMMING: Suid-Afrika is 'n land van kontraste - kontraste in die landskap, kulture en sakewêreld. Daar bestaan baie suksesvolle organisasies in Suid-Afrika. Minder suksesvolle organisasies kan baie leer by hierdie en ander suksesvolle internasionale organisasies. Besigheid het verander in 'n hoogs gesofistikeerde wetenskap en hoewel daar geen resep bestaan vir oornagsukses nie, kan die kriteria wat beskryf word in hierdie studie 'n organisasie se kanse op sukses verbeter. Die eerste deel van die studie fokus op 'n literatuurstudie oor nege kritiese faktore wat in suksesvolle organisasies geïdentifiseer is. Die studie spreek die volgende aan: visie, strategie, verbruiker fokus, vertroue, standaarde, dryfkrag, spanwerk, ondersteuning en "belonging". Die daarstelling en ontwikkeling van hierdie faktore binne die organisasie is fundamenteel in hoogs suksesvolle organisasies. Die studie definiëer en ontwikkel hierdie faktore in praktiese en verstaanbare kriteria wat gebruik en gemeet kan word binne 'n organisasie. Verder gebruik die studie hierdie kriteria om aan te dui waar 'n organisasie nie slaag nie en om algemene foute wat vermy kan word, uit te wys. Die studie voorsien ook sakemodelle om die kriteria te onwikkel. Die tweede deel van die studie fokus op 'n interne opname wat in Rubico (Pty) Ltd geloods is, om die kriteria wat in die eerste deel verduidelik is, te meet. Die opname beklemtoon areas waar Rubico (Pty) Ltd suksesvol is, maar identifiseer ook leemtes. Die opname kan gebruik word as 'n meetinstrument om insig oor tekortkominge in die organisasie te bekom en die gebruiker daarvan toe te rus vir effektiewe bestuur.

Murilo Rubião é visto como um caso raro na literatura brasileira: poucos autores produziram como ele uma ficção tão decididamente marcada por situações insólitas, eventos estranhos, cenas inusitadas. Não à toa, sua literatura é estudada a partir de discussões em torno do chamado fantástico contemporâneo (ou neofantástico, ou realismo fantástico, ou realismo mágico, ou realismo maravilhoso). Por agora, no entanto, a questão é outra: alguns engenhos em Rubião potencializam um horizonte de pensamento que promove reflexões sobre a noção de não-senso (não-significado). O não-senso é uma possibilidade, por assim dizer, transgenérica - ainda que por vezes possa ser decidido em melhores circunstâncias no que se convencionou chamar, genericamente, literatura nonsense, literatura do absurdo e mesmo literatura fantástica. A fim de fazer jus a este horizonte, esta dissertação cruza os contos, animada por uma lógica do acontecimento, buscada fora das tradições platônicas e aristotélicas, criando ao longo dos capítulos cenários e instâncias associativas que, por sua vez, solicitam algumas distinções: explicação laboratorial e experiência lógica, senso-significado e senso-sentido, imagem e imagem pura, ser e extra-ser. A discussão aqui travada visa contribuir para a prática de uma experiência na literatura de Rubião.
Murilo Rubião is seen as a rare case in Brazilian literature: few authors have produced a fiction so strongly marked by unusual situations, strange events, and unusual scenes. Not for nothing, his literature is studied starting by discussions on the so-called contemporary fantastic (or neo-fantastic, or fantastic realism, or magic realism, or marvelous realism). For now, however, the question is another one: some of Rubiãos pyrotechnics empower a horizon of thought that promotes reflections on the notion of nonsense (non-meaning). The nonsense is, so to speak, a transgender possibility - though sometimes it can be determined, in the best circumstances, in what is generically called nonsense literature, literature of the absurd, and even fantastic literature. In order to make justice to this horizon, this dissertation travels the tales, it animated by a logic of the event, outside of the Platonic and Aristotelian traditions, creating, throughout the chapters, sceneries and associative instances which, in turn, ask for some distinctions: laboratorial explanation and logic experience, sense-meaning and sense-sense, image and pure image, being and extra-being. The discussion promoted here aims to contribute to the practice of an experience in the literature of Rubião.

Diurnal changes of initial and total activity and content of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) under conditions of ambient (350 µmol mol-1) and elevated (E = 700 µmol mol 1) concentration CO2 were measured in needles of Norway spruce. Needles of Norway spruce were taken on 22th July in two-hours from 3:30 a. m. till 10:30 p. m. The Rubisco activity was determined by spectrophotometry, the Rubisco content was detected by SDS-PAGE. The Rubisco activity was in most samples statistically significantly lower in needles cutlivated under ambient carbon dioxide then in needles cultivated under elevated carbon dioxide. Diagrams of the Rubisco activity shows absence of night inhibitor CA1P. The Rubisco activity was directly proportional to the intensity of photosynthetically active radiation in time from 7:00 a. m. till 7:30 p. m. The Rubisco content was statistically significantly higher in needles of Norway spruce cultivated under ambient carbon dioxide than in needles cultivated under elevated CO2, which shows acclimation of the Rubisco content during long-term effect of elevated CO2 concentration.

Almost every carbon atom that our bodies are made of and clothed in, at one point or another saw the active site of the enzyme, ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). This enzyme, one of the largest in nature at ~550 kDa, is also said to be the most abundant in nature, constituting up to 50% of soluble protein in land plants. It is however, notoriously inefficient at fixing carbon dioxide, due to its slow catalytic turnover, low affinity for atmospheric CO2, and its use of both CO2 and O2 as substrates for competing reactions. For this reason, Rubisco has also been one of the most intensively studied enzymes. The potential harvest yield of crops has been shown to be limited by the rate at which atmospheric carbon is fixed by Rubisco. As a result much focus is on studying and engineering Rubisco in order to increase the overall efficiency of biomass production, to cope with the fuel, fibre and food needs of a growing global population. Since Rubisco is one component of a system, the demand for developing tools to study and engineer Rubisco in light of its wider interactome and regulatory networks, is ever increasing. This thesis describes the development of tools to study the function of Rubisco. It includes the development of a novel method for purifying the enzyme using hydrophobic interaction chromatography. Different populations of Rubisco were isolated with distinct maximal rates of carboxylation, possibly reflecting differences in hydrophobic characteristics. It also contains the development of a spectroscopic activity assay for Rubisco activity, and an enzyme-linked immunosorbent assay (ELISA) for Rubisco and its catalytic chaperone, Rubisco Activase. These tools were then applied to investigate the influence of cellulose biosynthesis inhibition (CBI) on Rubisco in Arabidopsis seedlings, to investigate any potential sink-regulation of the activity or levels of Rubisco. It was found that specific Rubisco activity was reduced as a result of CBI, and rescued by providing osmotic support, thus implicating turgor pressure as a potential mechanism. Finally, preliminary results were obtained which demonstrate the potential of mass spectrometry for measuring relative levels of Rubisco ions generated by MALDI (matrix-assisted laser desorption ionisation), showing that this can be a useful method for use in interactome studies in conjunction with other tools.

La nécessité de coordonner l’expression des gènes provenant de génomes différents chez les plantes a conduit à l’émergence de mécanismes imposant un contrôle nucléaire sur l’expression génétique de l’organelle. Des signaux antérogrades, exercés par des protéines reconnaissant des séquences spécifiques, existent en parallèle avec un contrôle des synthèses chloroplastiques dépendant de l’assemblage (CES). Ensemble, ils coordonnent la formation stoichiométrique des complexes photosynthétiques.La Ribulose bisphosphate carboxylase/oxygénase (Rubisco) est une enzyme localisée dans le chloroplaste qui contient deux sous-unités. La grande sous-unité (LSU) et la petite sous-unité (SSU) sont codées par les génomes chloroplastique et nucléaire respectivement. Elles s’assemblent dans le stroma du chloroplaste pour former une holoenzyme hexadécamérique (LSU8SSU8). Pendant mon travail au laboratoire, j’ai tenté de décrire les étapes régulatrices majeures de la synthèse de la Rubisco chez Chlamydomonas reinhardtii en me focalisant sur la régulation post-transcriptionelle de la LSU.J’ai montré que la protéine PPR – MRL1 est un facteur limitant pour l’accumulation de l’ARN messager de rbcL. Bien qu’il ait été décrit précédemment comme un facteur stabilisateur du transcrit susnommé, MRL1 s’est révélé avoir un rôle dans la traduction.J’ai par ailleurs démontré que chez Chlamydomonas, l’expression de la Rubisco est contrôlée par la présence de la SSU. En son absence, la traduction de rbcL est inhibée par son propre produit – la grande sous-unité non assemblée. J’ai pu montrer qu’un intermédiaire d’assemblage, constitué de LSU en complexe avec sa chaperonne RAF1, est nécessaire pour cette régulation, ce qui prouve que ce processus dépend de l’état d’oligomérisation de la LSU. Parallèlement, j’ai caractérisé le devenir de la LSU non assemblée quand la régulation CES est perturbée, et grâce à cela ait contribué à améliorer la connaissance de son processus de repliement et d’assemblage
The necessity to coordinate the expression of genes originating from different genomes within the plant cell resulted in the appearance of mechanisms imposing nuclear control over organelle gene expression. Anterograde signaling through sequence-specific trans-acting proteins (OTAFs) coexists in the chloroplast with an assembly dependent control of chloroplast synthesis (CES process) that coordinates the stoichiometric formation of photosynthetic complexes.Ribulose bisphosphate carboxylase/oxygenase (Rubisco) is a chloroplast-located carbon fixing enzyme constituted of two subunits. Large subunit (LSU) and small subunit (SSU) are encoded in the chloroplast and nuclear genomes respectively. In the stroma they assemble to form a hexadecameric holoenzyme (LSU8SSU8). In this study I tried to highlight major regulatory points of its synthesis in Chlamydomonas reinhardtii focusing on the posttranscriptional regulation of LSU.I showed that the MRL1 PPR protein is a limiting factor for rbcL mRNA accumulation. Whereas it has been previously designated as a stabilization factor for the abovementioned transcript, MRL1 appeared also to have a function in rbcL translation.Most notably, I have demonstrated that in Chlamydomonas reinhardtii Rubisco expression is controlled by the small subunit (SSU) presence. In its absence rbcL undergoes an inhibition of translation through its own product – the unassembled Rubisco large subunit. This process depends on LSU-oligomerization state as I was able to show that the presence of a high order LSU assembly intermediate bound to the RAF1 assembly chaperone is essential for the regulation to occur. In parallel I shed light on the fate of unassembled LSU in a deregulated CES context, thereby improving our understanding of the process of its folding and assembly

Made available in DSpace on 2016-03-15T19:46:39Z (GMT). No. of bitstreams: 1 Veronica Nogueira Martins.pdf: 560796 bytes, checksum: 152c26660d2031002f2ec2b90c9a0dd8 (MD5) Previous issue date: 2008-02-18
Fundo Mackenzie de Pesquisa
Se sabe que el Modernismo se inicia en 1922, con la Semana de Arte Moderna. A partir de ese movimiento, la literatura brasileña es constituida, a través de los años, por una serie de corrientes ecléticas: generación de 45, concretismo, poesía marginal, regionalismo, nouveau roman, entre otros. Es en esta atmosfera contemporánea que surge en el âmbito ficcional el escritor originario de Minas Gerais, Murilo Rubião. Su obra intimista parte de una literatura fantástica humanizada para representar la angustia del hombre moderno frente a los problemas sociales y sicológicos. Para mejor entender la obra de Murilo Rubião, recorremos varios caminos. Para el estúdio de la literatura fantástica, investigamos sus vertientes entre extraño, maravilloso, mágico, sobrenatural y humanístico, así como innúmeras obras independientes de su estructura desde los textos de la Antigüedad Clásica hasta la actualidad, siempre buscando encontrar en el fantástico contemporáneo las respuestas para el universo muriliano: lo insólito, lo supra-real, lo no-real, lo irreal que aparece sin sorpresas, con el fin de representar el absurdo de la condición humana en confronto con la realidad represora.
Sabe-se que o Modernismo inicia em 1922, com a Semana de Arte Moderna. A partir desse movimento, a literatura brasileira é constituída, ao longo dos anos, por uma série de correntes ecléticas: geração de 45, concretismo, poesia marginal, regionalismo, nouveau roman, entre outros. É nesta atmosfera contemporânea que surge no âmbito ficcional o escritor mineiro Murilo Rubião. Sua obra intimista parte de uma literatura fantástica humanizada para representar a angústia do homem moderno diante dos problemas sociais e psicológicos. Para melhor entender a obra de Murilo Rubião, percorremos vários caminhos. Para o estudo da literatura fantástica, pesquisamos suas vertentes entre estranho, maravilhoso, mágico, sobrenatural e humanístico, bem como inúmeras obras independentes de sua estrutura desde os textos da Antiguidade Clássica até a atualidade, sempre buscando encontrar no fantástico contemporâneo as respostas para o universo muriliano: o insólito, o supra-real, o não-real, o irreal que aparece sem surpresas, a fim de representar o absurdo da condição humana em confronto com a realidade repressora.

Rubisco, the enzyme that catalyzes the assimilation of atmospheric CO2 and sustains the vast majority of food chains in the Biosphere, presents functional inefficiencies limiting the photosynthetic process. Rubisco is a slow enzyme and can not fully discriminate between CO2 and O2. When oxygen catalysis takes place, CO2 is released and energy is dissipated in the process of photorespiration. The existence of interspecific species variability in the catalytic properties of Rubisco suggests that this enzyme has been adapting to the prevailing environmental conditions, in particular to changes in CO2 concentration at the catalytic site and different thermal conditions. These findings offer new alternatives on genetic manipulation of Rubisco in order to overcome their inefficiencies and improve crop yields. However, the great structural and biochemical complexity of Rubisco is actually limiting a successful improvement. This is precisely the aim of this thesis: to expand the molecular and biochemical knowledge on the evolution of Rubisco to further understand and manipulate the enzyme. In this sense, the objectives of this thesis were: i) to investigate the genetic variability of Rubisco large subunit (L-subunit) and its evolution in different groups of plants, and ii) to explore the temperature dependence of Rubisco kinetic constants. Four experiments were done to answer these objectives. Experiments 1 and 2 shared a common pattern that consisted in selecting phylogenetically related species (174 species of Fagales in experiment 1, and 60 species of bromeliads and orchids in experiment 2) to describe Rubisco L-subunit sequence variability and to investigate the existence of positively selected sites related to particular environments and leaf traits. Experiments 3 and 4 were focused on the study of Rubisco kinetic response to temperature. Thus, experiment 3 consisted in a bibliographic compilation to study the thermal sensitivity of Rubisco turnover rate for carboxylation (kcat c). In experiment 4, the kinetic parameters of Rubisco and their response to temperature in 20 economically important crops were measured. In both experiments we modeled the effect of the observed kinetic variability on the ability of Rubisco to assimilate CO2 under different scenarios of CO2 concentration. Experiments 1 and 2 showed, first, that there was a great variability in Rubisco L-subunit in closely related species. Specifically, the 174 Fagales species were distributed into 29 haplotypes (groups of species with the same sequence), the 158 Quercus species in 21 haplotypes, and 19 haplotypes in orchids and 23 haplotypes in bromeliads. In all studied groups, the analysis showed that large part of this variability was determined by natural selection, corroborating the hypothesis of processes of adaptive change in Rubisco. Furthermore, in experiment 1, evidences of positive selection were found in terms of leaf habit and climate, both traits influencing the CO2 concentration at the site of carboxylation. This finding is a clear evidence that species adjust their Rubisco depending on the prevailing environmental conditions. By contrast, in experiment 2, positive selection processes could not be related to CAM photosynthetic mechanism. In any case, in all studied groups appeared co-evolving pairs of amino acid sites, located in important Rubisco regions for the functionality and structure of the enzyme. The implementation of a mathematical model of decision trees (DT) for sequence analysis permitted to relate sites variability to environmental and leaf traits. DT results corroborated, in part, observations of positive selection tests, thus validating the use of alternative models in the search for variable sites. Furthermore, in bromeliads and orchids, DT revealed a relation between sites variability and variables indicative of the degree of expression of CAM (δ13C and leaf thickness). In bromeliads and orchids interspecific variability in the catalytic constants of Rubisco was observed, part of which explained by the existence of carbon concentration mechanism in CAM plants. However, this catalytic variability could not be directly related to sites under positive selection or resolved by DT. In experiment 3, distinct kcatc photosynthetic response to temperature appeared among the studied groups. Thus, the highest and lowest activation energy (ΔHa) values for kcatc were observed in Rhodophyta and Chlorophyta, respectively. In terrestrial plants, C3 species from warm habitats and C4 species showed a higher ΔHa for kcatc than C3 plants from cold habitats. These results suggest that Rubisco evolved by adjusting the sensitivity of their kinetic properties to temperature indicating thermal adaptation to local conditions. In experiment 4, Rubisco kinetic parameters (Michaelis-Menten constant for CO2, specificity factor and kcatc) from the 20 studied crops showed interspecies variability at three temperatures of measurement (15, 25 and 35 °C). Variability in ΔHa of kinetic parameters was significant among all crop species and photosynthetic mechanisms. This variability could not be related to their domestication region climate, possibly due to subsequent processes of artificial selection. The use of measured values in mathematical models of photosynthesis quantified the importance of improving Rubisco in different crops at changing temperature and CO2 availability conditions. This thesis presents, under an evolutionary background, relevant information to improve Rubisco by bioengineering processes. The combined analysis of positive selection and coevolution are useful to elucidate interactions between amino acids that should be taken into account when designing better Rubiscos. In addition, the application of DT helps in the construction of relationships between the amino acid variability and the environment in which species evolve. Moreover, this thesis represents the most convincing evidence that Rubiscos of different species differ not only in catalytic constants at 25 °C, but also exhibit different response to temperature. The data published here offer the possibility to increase the accuracy of leaf photosynthesis models and addressed the need for improvement of Rubisco in species of high agricultural interest.
La Rubisco, enzima que cataliza la asimilación de CO2 atmosférico y sustenta la inmensa mayoría de cadenas tróficas de la Biosfera, presenta ineficiencias que limitan el proceso fotosintético. La Rubisco es lenta y puede “confundirse” de sustrato catalizando la fijación de O2 en el proceso de fotorrespiración, que termina liberando CO2 y disipando energía. La existencia de variabilidad interespecífica en las características catalíticas de la Rubisco sugiere que esta enzima se ha sido adaptando a las condiciones ambientales reinantes, en particular, a cambios en la concentración de CO2 en el sitio de catálisis y a las diferentes condiciones térmicas. Estos hallazgos han renovado la esperanza de manipulación genética de la Rubisco con el objetivo de superar sus ineficiencias y mejorar el rendimiento de los cultivos. Sin embargo, el desconocimiento aún presente en aspectos derivados de la gran complejidad estructural y bioquímica de la Rubisco limita, hoy en día, el éxito de mejora. Éste es, precisamente, el enfoque de la presente tesis: ampliar el conocimiento de la evolución molecular y bioquímica de la Rubisco para avanzar en la comprensión y manipulación de la enzima con mayores garantías de éxito. En este sentido, los objetivos de esta tesis fueron: i) investigar la variabilidad genética de la subunidad grande de la Rubisco y su evolución en diferentes grupos de plantas, y ii) explorar la dependencia térmica de las constantes cinéticas de la Rubisco. Para dar respuesta a estos objetivos, se llevaron a cabo 4 experimentos. Los experimentos 1 y 2 presentaron un patrón común consistente en seleccionar especies próximas filogenéticamente (174 especies de Fagales en el experimento 1, y 60 especies de bromelias y orquídeas en el experimento 2) para descifrar la variabilidad en la secuencia de la subunidad grande de la Rubisco e investigar la existencia de sitios aminoacídicos seleccionados positivamente en función del ambiente y caracteres morfológicos y fisiológicos foliares. Los experimentos 3 y 4 se centraron en el estudio de la respuesta de la cinética de la Rubisco a la temperatura. Así, en el experimento 3 se llevó a cabo una compilación bibliográfica para el estudio de la sensibilidad térmica del número de recambio catalítico para la reacción de carboxilación de la Rubisco, kcat c (el parámetro cinético más ampliamente estudiado en todos los grupos fotosintéticos). En el experimento 4 se midieron los parámetros cinéticos de la Rubisco y su respuesta a la temperatura en 20 cultivos económicamente importantes. En ambos experimentos se modelizó el impacto de la variabilidad observada sobre la capacidad asimiladora de la Rubisco bajo diferentes escenarios de disponibilidad de CO2. Los resultados de los experimentos 1 y 2 mostraron, por primera vez, la existencia de una gran variabilidad en la secuencia de la subunidad grande de la Rubisco en especies próximas taxonómicamente. En concreto, las 174 especies estudiadas de Fagales se distribuyeron en 29 haplotipos (grupos de especies con la misma secuencia), 21 haplotipos en las 158 especies de Quercus, 19 haplotipos en orquídeas y 23 haplotipos en bromelias. En todos los grupos estudiados, los análisis demostraron que una parte importante de esta variabilidad había sido fijada por la selección natural, corroborando la hipótesis de la existencia de procesos de cambio adaptativo en la Rubisco. Además, en el experimento 1, se encontraron evidencias de selección positiva en función del hábito foliar y del clima, ambos caracteres determinantes de la concentración de CO2 en el sitio de carboxilación. Este hallazgo supone la primera prueba inequívoca de que las especies ajustan su Rubisco en función de las condiciones ambientales prevalentes. Por el contrario, en el experimento 2, los procesos de selección positiva no se relacionaron aparentemente con el mecanismo fotosintético CAM. En cualquier caso, en todos los grupos estudiados aparecieron pares de sitios aminoacídicos con tendencia a coevolucionar, la mayoría ubicados en regiones importantes para la función y estructura de la Rubisco. Se implementó, de forma pionera, el modelo matemático de árboles de decisión (DT) para el análisis de secuencias y su relación con variables externas. Los resultados del DT corroboraron, en parte, las observaciones de los análisis de selección positiva, validando de esta forma la aplicación de modelos alternativos en la búsqueda de sitios variables. Además, en bromelias y orquídeas, los DT revelaron la existencia de cambios aminoacídicos específicos en función de variables indicadoras del grado de expresión de CAM (δ13C y espesor de hoja). En bromelias y orquídeas se observó variabilidad interespecífica en las constantes catalíticas de la Rubisco, parte de la cual se explicó por la existencia de mecanismos de concentración de carbono en plantas CAM. No obstante, esta variabilidad catalítica no se relacionó directamente con los cambios aminoacídicos detectados por los DT o bajo selección positiva. En el experimento 3, la respuesta de kcat c a la temperatura mostró diferencias entre los grupos fotosintéticos estudiados. Así, los valores más altos y más bajos para la energía de activación (ΔHa) de kcat c se observaron en Rhodophyta y Chlorophyta, respectivamente. En las plantas terrestres, las especies C3 de hábitats cálidos y las especies C4 presentaron una ΔHa de kcat c mayor que las plantas C3 de hábitats fríos. Estos resultados sugieren que la Rubisco ha evolucionado ajustando la sensibilidad de sus propiedades cinéticas a la temperatura e indican adaptación a las condiciones térmicas locales. En el experimento 4, los parámetros cinéticos de la Rubisco (constante de Michaelis-Menten para el CO2, factor específico y kcat c ) de los 20 cultivos estudiados mostraron variabilidad interespecífica a las tres temperaturas de ensayo (15, 25 y 35 °C). La variabilidad en la ΔHa de los parámetros cinéticos fue significativa entre todas las especies de cultivo y tipos fotosintéticos, si bien dicha variabilidad no se relacionó con el clima en la región de domesticación, posiblemente debido a procesos posteriores de selección artificial. La aplicación de datos específicos en los modelos matemáticos de fotosíntesis cuantificó la importancia de mejora de la Rubisco en los diferentes cultivos según condiciones cambiantes de temperatura y disponibilidad de CO2. Bajo un trasfondo evolutivo, esta tesis presenta información relevante para procesos de bioingeniería direccionados a la mejora de la Rubisco. Los análisis combinados de selección positiva y coevolución resultan útiles para resolver interacciones entre aminoácidos que deberían tenerse en cuenta a la hora de diseñar mejores Rubiscos. Además, la aplicación de los DT ayuda a generar relaciones entre la variabilidad aminoacídica y el ambiente en el que evolucionan las especies. Por otra parte, esta tesis supone la evidencia más convincente de que Rubiscos de diferentes especies no sólo presentan diferencias en las constantes catalíticas a 25 ºC, sino que también presentan diferente respuesta al rango fisiológico de temperaturas. Los datos aquí publicados ofrecen la posibilidad de aumentar la precisión de los modelos de fotosíntesis en hoja, y direccionan la mejora de Rubisco en especies de alto interés agrícola.
La Rubisco, l’enzim que catalitza l’assimilació del CO2 atmosfèric i sustenta la immensa majoria de cadenes tròfiques de la Biosfera, presenta ineficiències que limiten el procés fotosintètic. La Rubisco és lenta i es pot “confondre” de substrat, catalitzant la fixació d’O2 en el procés de fotorespiració, que acaba alliberant CO2 i dissipant energia. L’existència de variabilitat interespecífica en les característiques catalítiques de la Rubisco suggereix que aquest enzim ha anat adaptant-se a les condicions ambientals predominants, en particular, a canvis a la concentració de CO2 al lloc de catàlisi i a les diferents condicions tèrmiques. Aquests descobriments han renovat l’esperança de manipulació genètica de la Rubisco amb l’objectiu de superar les seves ineficiències i millorar així el rendiment dels cultius. No obstant, el desconeixement encara present a alguns aspectes derivats de la gran complexitat estructural de la Rubisco limita, avui en dia, l’èxit de millora. Aquest és precisament l’enfocament de la present tesi: ampliar el coneixement de l’evolució molecular i bioquímica de la Rubisco per avançar en la comprensió i manipulació de l’enzim, i així obtenir majors garanties d’èxit. En aquest sentit, els objectius d’aquesta tesi foren: 1) investigar la variabilitat genètica de la subunitat gran de la Rubisco i la seva evolució dins diferents grups de plantes, 2) explorar la dependència tèrmica de les constants cinètiques de la Rubisco. Per a poder donar resposta a aquests objectius, es varen dur a terme quatre experiments. Els experiments 1 i 2 presentaren un patró basat en la selecció d’espècies pròximes filogenèticament (174 espècies de Fagals en el experiment 1 i 60 espècies d’orquídies i bromèlies en el experiment 2) per tal de desxifrar la variabilitat en la seqüència de la subunitat gran de la Rubisco i investigar l’existència de llocs aminoacídics seleccionats positivament en funció de l’ambient i dels caràcters morfològics i fisiològics foliars. Els experiments 3 i 4 es varen centrar en l’estudi de la resposta de la cinètica de la Rubisco a la temperatura. Així, en el experiment 3 es va dur a terme una compilació bibliogràfica per a l’estudi de la sensibilitat tèrmica del nombre de recanvi catalític per a la reacció de carboxilació de la Rubisco, kcat c (el paràmetre cinètic més àmpliament estudiat en tots els grups fotosintètics). En el experiment 4 es varen mesurar els paràmetres cinètics de la Rubisco i la seva resposta a la temperatura dins 20 cultius econòmicament importants. En ambdós experiments es va modelitzar l’impacte de la variabilitat observada sobre la capacitat assimiladora de la Rubisco sota diferents escenaris de disponibilitat de CO2. Els resultats dels experiments 1 i 2 varen mostrar, per primer cop, l’existència d’una gran variabilitat dins la seqüència de la subunitat gran de la Rubisco a espècies pròximes taxonòmicament. En concret, les 174 espècies estudiades de Fagals es varen distribuir en 29 haplotips (grups d’espècies amb la mateixa seqüència), 21 haplotips dins les 158 espècies de Quercus, 19 haplotips dins orquídies i 23 haplotips dins les bromèlies. Dins tots els grups estudiats, les anàlisis demostraren que una part important d’aquesta variabilitat havia estat fixada per la selecció natural, corroborant la hipòtesi de l’existència de canvis adaptatius a la Rubisco. A més, en el experiment 1 es varen trobar evidències de selecció positiva en funció de l’habitat foliar i del clima, ambdós caràcters determinants de la concentració de CO2 en el lloc de carboxilació. Aquest descobriment suposa la primera prova inequívoca de que les espècies ajusten la Rubisco en funció de les condicions ambientals que predominen. Per el contrari, en el experiment 2 els processos de selecció positiva no es varen relacionar aparentment amb el mecanisme fotosintètic CAM. En qualsevol cas, dins tots els grups estudiats varen aparèixer parells de llocs aminoacídics amb tendència a coevolucionar, la majoria ubicats a llocs importants per a la funció i estructura de la Rubisco. Es va implementar de forma pionera el model matemàtic d’arbres de decisió (DT) per a l’anàlisi de seqüències i la seva relació amb variables externes. Els resultats del DT varen corroborar en part les observacions de les anàlisis de selecció positiva, validant així l’aplicació de models alternatius per a la recerca de llocs variables. A més, dins bromèlies i orquídies, els DT varen revelar la existència de canvis aminoacídics específics, en funció de variables indicadores d’expressió de CAM (δ13C i gruixa de fulla). Dins bromèlies i orquídies es va observar variabilitat interespecífica en les constants catalítiques de la Rubisco, part de la qual es va explicar per l’existència de mecanismes de concentració de carboni dins plantes CAM. No obstant, aquesta variabilitat catalítica no es va relacionar directament amb els canvis aminoacídics detectats mitjançant els DT o sota selecció positiva. En el experiment 3, la resposta de kcat c a la temperatura va mostrar diferències entre els grups fotosintètics estudiats. Així, els valors més alts i més baixos per a l’energia d’activació (ΔHa) de kcat c es varen observar a Rhodophyta i Chlorophyta, respectivament. A les plantes terrestres, les espècies C3 d’hàbitats càlids i les espècies C4 presentaren una ΔHa de kcat c major que les plantes C3 d’hàbitats freds. Aquests resultats suggereixen que la Rubisco ha evolucionat ajustant la sensibilitat de les seves propietats cinètiques a la temperatura i indiquen una adaptació a les condicions tèrmiques locals. En el experiment 4, els paràmetres cinètics de la Rubisco (constant de Michaelis-Menten per al CO2, factor específic i kcat c ) dels 20 cultius estudiats varen mostrar variabilitat interespecífica a les tres temperatures d’assaig (15, 25 i 35 °C). La variabilitat dins la ΔHa dels paràmetres cinètics va ser significativa entre totes les espècies de cultius i tipus fotosintètics, si bé aquesta variabilitat no es va relacionar amb el clima de la regió de domesticació, possiblement degut a processos posteriors de selecció artificial. L’aplicació de dades específiques en els models matemàtics de fotosíntesi va quantificar la importància de millora de la Rubisco en els diferents cultius segons condicions canviants de temperatura i disponibilitat de CO2. Sota un rerefons evolutiu, aquesta tesi presenta informació rellevant per a processos de bioenginyeria enfocats a la millora de la Rubisco. Les anàlisis combinades de selecció positiva i coevolució resulten útils per a resoldre interaccions entre aminoàcids que haurien de tenir-se en compte a l’hora de dissenyar millors Rubiscos. A més, l’aplicació dels DT ajuda a generar relacions entre la variabilitat aminoacídica i l’ambient en que evolucionen les espècies. Per altra banda, aquesta tesi suposa l’evidència més convincent de que Rubiscos de diferents espècies no només presenten diferències en les constants catalítiques a 25 °C, sinó que també presenten diferents respostes al rang fisiològic de temperatures. Les dades aquí publicades ofereixen la possibilitat d’augmentar la precisió dels models de fotosíntesi a nivell de fulla i marquen el camí per a la millora de la Rubisco dins les espècies d’alt interès agrícola.

Orientador: Vilma Sant'Anna Areas
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem
Made available in DSpace on 2018-08-02T23:37:10Z (GMT). No. of bitstreams: 1 Furuzato_FabioDobashi_M.pdf: 5374997 bytes, checksum: 70b61dcd7096ea379c133ae98f726de4 (MD5) Previous issue date: 2002
Resumo: Este trabalho é dividido em três partes. Na primeira, investigamos o percurso da obra do contista mineiro Murilo Eugênio Rubião (1916-1991), juntamente com a sua recepção crítica. Na segunda, partindo da afirmação de que Murilo seja o precursor do fantástico moderno em nossa prosa de ficção, realizamos um estudo teórico sobre este gênero literário. Na terceira parte, buscamos descrever todos os contos do autor, em função de um determinado conceito de fantástico. Por fim, levantamos uma hipótese geral sobre o sentido da obra muriliana, buscando relacionar tudo o que foi discutido
Abstract: This work is divided in three parts. On the first, it is investigated the work course of the storyteller, from Minas Gerais, Murilo Eugênio Rubião (1916 - 1991), together with the reviews he had received. On the second part, setting forth from the statement that Murilo is the predecessor of the modem fantastic stile in our fiction prose, we made a theoretical study about this literature genre. On the third part, we sought to describe all of the author's narratives, focusing on a specific concept of the fantastic. Finally, we raised a general hypothesis about the meaning of Murilo's work, trying to connect everything that had been discussed.
Mestrado
Mestre em Teoria e História Literária

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-05-16T18:07:38Z No. of bitstreams: 1 texto completo.pdf: 463415 bytes, checksum: c2d919351836ddcda64ea3d7df498700 (MD5)
Approved for entry into archive by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-05-16T18:08:11Z (GMT) No. of bitstreams: 1 texto completo.pdf: 463415 bytes, checksum: c2d919351836ddcda64ea3d7df498700 (MD5)
Approved for entry into archive by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-05-16T18:08:22Z (GMT) No. of bitstreams: 1 texto completo.pdf: 463415 bytes, checksum: c2d919351836ddcda64ea3d7df498700 (MD5)
Made available in DSpace on 2018-05-16T18:08:31Z (GMT). No. of bitstreams: 1 texto completo.pdf: 463415 bytes, checksum: c2d919351836ddcda64ea3d7df498700 (MD5) Previous issue date: 2006-09-20
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Este trabalho examina aspectos da vida e da obra do contista mineiro Murilo Rubião, principalmente no período de 1956 a 1960, época em que ele residiu em Madrid. A investigação é feita a partir de um depoimento que o contista concedeu em entrevista, relembrando aquela fase de sua vida, quando, pela primeira vez, sofreu o problema do exílio. Tendo como hipótese que o exílio de Murilo Rubião apresenta não só o aspecto geográfico, observo outras particularidades no que diz respeito ao exílio deste escritor, o qual vai se refletir em toda a sua obra. A fundamentação teórica de Edward Said, Arthur Schopenhauer, Octavio Paz, Julia Kristeva e Stuart Hall possibilitam um diálogo com este estudo. O texto de Murilo que ilustra este trabalho é o conto “Teleco, O Coelhinho”, produto de seu tempo em Madrid, época que é detalhadamente examinada através de sua correspondência passiva.
This work examines some aspects of the life and work of Murilo Rubião, a short story writer from Minas Gerais, focusing mainly in the years he lived in Madrid, from 1956 to 1960. This study was triggered by some comments of the writer, in an interview, as to how much he had felt an exile at that time. Setting off with the idea that Murilo Rubião’s exile is a characteristic not only concerning his geographic absence, the work deals on different aspects of his sense of exile, which reflects on his written production. The work falls back on the thoughts of Edward Said, Arthur Schopenhauer, Octa vio Paz and Julia Kristeva as far as the questions of exile are concerned. The short story studied in depth is “Teleco, o coelhinho”, which was written during the time highlighted here. The mentioned period is studied in detail through an examination of the letters Rubião received in those years, available in the UFMG archive.

This diploma thesis deals with dynamic of accumulation of non-structural carbohydrates and activity of Rubisco enzyme at elevated concentration of CO2 on beech (Fagus sylvatica L.). Three years old seedlings of beech were cultivated in minisphere with ambient (385 µmol•mol-1, variant A), and with elevated concentration CO2 (700 µmol•mol-1, variant E) for four months. In every variant the first half of plants was fertilized by nitrogen (variant N+) and the second half was control (variant N-). Plants used for experiment were at first adapted for darkness for 12 hours. Subsequently tested leaves were cut off, leafstalk including short segment of branch (approximately 1 cm) was inserted into 0.7 M solution of sucrose (variant S) or water (variant V) and exposed to radiation 200 mol•m-2•s-1 for 0, 30, 60, 120, 180 minutes. Then leaf area and fresh mass of leaf blade were established, samples were fixed in liquid nitrogen and stored in deep freezer to analysis in –70 °C. Rubisco content was determined by SDS-PAGE method, Rubisco activity spectrofotometrically and content of non-structural carbohydrates by anthrone method and HPLC method. Rubisco content was significantly lower in the N- variant than in N+ variant. Rubisco content was also significantly lower in E than in A variant, which is an evidence of down-regulation. Rubisco activity is moderately stimulated at E variant with time, but differences between variant A and E are not statistically significant. Influence of sucrose feeding to Rubisco activity was not proved. Significant differences were detected by anthrone method in non-structural carbohydrates content between variants S and V, but not between variants A and E. Statistically significant increase of sucrose content with time was detected by HPLC method at variant AS, but not at variant ES.

Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第9642号
農博第1270号
新制||農||846(附属図書館)
学位論文||H14||N3674(農学部図書室)
UT51-2002-G400
京都大学大学院農学研究科応用生命科学専攻
(主査)教授 吉川 正明, 教授 伏木 亨, 教授 北畠 直文
学位規則第4条第1項該当

Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-02-28T18:23:04Z No. of bitstreams: 1 cinthialopesdeoliveira.pdf: 428797 bytes, checksum: c02109f4e35b15ee2ef02ca0b408cc1a (MD5)
Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-03-01T15:59:37Z (GMT) No. of bitstreams: 1 cinthialopesdeoliveira.pdf: 428797 bytes, checksum: c02109f4e35b15ee2ef02ca0b408cc1a (MD5)
Made available in DSpace on 2018-03-01T15:59:37Z (GMT). No. of bitstreams: 1 cinthialopesdeoliveira.pdf: 428797 bytes, checksum: c02109f4e35b15ee2ef02ca0b408cc1a (MD5) Previous issue date: 2013-12-17
PROQUALI (UFJF)
Este estudo apresenta a metamorfose como elemento temático e metalinguístico nos contos de Murilo Rubião. Tem por finalidade abordar a representação da fragmentação da personalidade do indivíduo moderno nos contos: O ex-mágico da Taberna Minhota, O pirotécnico Zacarias, Os dragões, Teleco, o coelhinho e Alfredo cujas temáticas abordam a fabulação da metamorfose. Esses contos revelam, ainda, características internas da obra do escritor como a reescrita dos contos, a intertextualidade epigráfica e a escrita cíclica. Sob o véu da fantasticidade, os contos revelam reflexões existenciais com as quais os leitores podem se identificar. Por meio da indiferença e da estagnação de algumas personagens dos contos, revela-se o inconformismo dos indivíduos e a dificuldade dos relacionamentos sociais. Por fim, conclui-se que o Fantástico é um véu da literatura que pode permitir um posicionamento crítico diante dos acontecimentos. A fabulação natural do ser humano lhe dá capacidade, portanto, de construir realidades alternativas que espelhem novas significações para as relações entre o indivíduo e a sociedade.
This study presents metamorphosis as a thematic and metalinguistic element in the short stories of Murilo Rubião. It aims to demonstrate the fragmentation of personality of the modern man in the short stories: O ex-mágico da Taberna Minhota, O pirotécnico Zacarias, Os dragões, Teleco, o coelhinho e Alfredo whose themes manifest the fable of metamorphosis. These tales also reveal internal features of the work of the writer such as the rewriting of the tales, epigraphic intertextuality and cyclical writing. Under the veil of the fantastic, the short stories reveal existential reflections with which readers can identify. Through the indifference and stagnation of some characters of the tales, they reveal the reluctance of individuals and the difficulty of social relationships. Finally, it is concluded that the Fantastic is a type of literature that can allow for a critical stance towards events. The natural fabulation of human beings offers the ability, therefore, to build alternate realities that reflect new meanings in the relationship between man and society.

Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xiii, 149 p.; also includes graphics. Includes abstract and vita. Advisor: F. Robert Tabita, Dept. of Microbiology. Includes bibliographical references (p. 144-149).

In this diploma thesis, the diurnal changes of initial and total Rubisco activity and Rubisco enzyme content in beech (Fagus sylvatica) were studied under conditions of ambient (A) CO2 concentration (350 µmol.mol-1) and elevated (E) CO2 concentration (700 µmol.mol-1) during the day. Samples were taken on July 8th (from 10:00 to 21:30), on July 9th (from 04:00 to 12:00) and then on July 22th (from 04:00 to 21:30). The initial and total activity were measured spectrophotometrically and the activation level was calculated from the ratio of initial and total activities. Rubisco enzyme content was determined by SDS-PAGE method and the initial and total specific activity were calculated from the ratio of initial or total activity and Rubisco enzyme content. In our experiment no statistically significant difference was found between Rubisco activities in beeches cultivated under conditions of ambient CO2 concentration and elevated CO2 concentration, so any down-regulation of Rubisco activity did not appear under the influence of ambient CO2 concentration. Diurnal changes of Rubisco activities showed only statistically nonsignificant fluctuation. After daylight no significant increase of total Rubisco activity was observed, which demonstrates the absence or the immaterial effect of CA1P night inhibitor in beech. Intensive fluctuation of the activation level (40–90 %) proves the regulation of photosynthesis during the day via Rubisco enzyme carbamylation. Rubisco enzyme content in beech cultivated under conditions of ambient CO2 concentration was lower than that one in beech cultivated under conditions of elevated CO2 concentration. Then down-regulation of Rubisco enzyme content is presented under conditions of ambient CO2 concentration. Before daylight Rubisco enzyme content showed an indistinctive minimum on the level of statistical significance, during the day only nonrelevant fluctuation was noticed.

Rodrigo Rubio es un escritor al que la mayoría de los críticos lo sitúan dentro del denominado realismo social y, más concretamente, dentro de un realismo existencial de fuertes raíces cristianas. Además, su literatura posee un alto contenido autobiográfico -desde el principio hasta el final de la misma-,con una fuerte reflexión individual y unas motivaciones psicológicas bastante profundas.El propio rubio siempre se manifestó como un firme defensor de la literatura comprometida, marcada por una fuerte vocación realista y por un irrenunciable carácter testimonial. De ahí su permanente defensa de la literatura como testimonio de la vida del ser humano y de su lucha diaria, muchas veces infructuosa, por encontrar la felicidad. Porque, para Rodrigo Rubio, literatura y vida son inseparables, tal y como siempre mostró a lo largo de su obra y como se ha pretendido poner de manifiesto incluso con el mismo título de esta Tesis Doctoral.
Rodrigo Rubio is a writer whom most critics have placed within the so-called social realism, and more precisely within an existential realism, with strong christian roots.Furthermore, his literature, has, from beginning to end, a high autobiographical content, together with a strong individual reflection and deep psychological motivations.Rubio himself always stood for committed literature with a strong realistic vocation and testimonial character. Hence, his permanent defence of literature as a testimony of the life of human beings and their daily, and so often fruitless, struggle for happiness. Because, for Rodrigo Rubio, literature an life cannot be separated, as he has showed all throughout his works, and the title of this Tesis Doctoral has intended to state.

This study combined in vivo leaf gas exchange, chlorophyll fluorescence, and instantaneous carbon isotope discrimination (D) analyses with in vitro measurement of Rubisco and PEPc activity and transcript abundance of key Rubisco and PEPc regulatory enzymes, Rubisco activase (RCA) and PEPc kinase (PPCKI ), and RCA protein abundance, to provide a novel molecular perspective on the co-regulation of carboxylase activity in M. crystallinum. In C₃ M. crystallinum, Rubisco activation state was highest during the photoperiod. C3 Rubisco activity remained uniform diurnally, mirrored by the pattern of stable CO₂ assimilation rate and protein abundance of both RCA isoforms, RCA1 and RCA2. RACE-PCR was used to identify RCA2 as the larger isoform in M. crystallinum. A marked decrease in RCA2 protein occurred during CAM induction, coincident with increased PEPc protein abundance and maximal PEPc activity. Diurnal Rubisco activity was regulated independent of light intensity and electron transport rate (ETR) following CAM induction. Rubisco activation state in CAM M. crystallinum was increased during the latter half of the photoperiod (mid CAM Phase III - Phase IV), coincident with low apparent PEPc activity and the final stages of titratable acidity breakdown. Increased RCA1 protein abundance during mid-CAM Phase III was observed coincident with an increase in Rubisco activation state of approximately one third. Modulation of diurnal Rubisco activity by RCA1 represented a potential regulatory mechanism unique to the CAM mode of M. crystallinum.

Photosynthesis is the process by which autotrophic photosynthetic organisms utilise light energy to assimilate CO2 into biomass, releasing O2 into the atmosphere as a by-product. Even though photosynthetic reactions were crucial in the “Great Oxygenation Event” of our atmosphere 2.4 billion years ago, these greatly limit crop yields. Hence, increasing the photosynthetic efficiency of light conversion into biomass has become a crucial practice to feed the increasing global population. Rubisco is a fundamental enzyme in the carbon reactions of photosynthesis, which fixates atmospheric carbon dioxide into biomass. However, due to its slow turnover (3 molecules of CO2 fixed per second) and inhibition of carboxylation reactions by oxygenation, Rubisco is a major bottleneck of carbon fixation in photosynthesis. Rubisco form I from higher plants is the most abundant form of Rubisco on earth. It is a complex enzyme consisting of 8 large and 8 small subunits, which forms a hexadecameric structure with a mass of 550 kDa in higher plants. Due to Rubisco’s multimeric nature, targeted mutagenesis experiments to investigate more efficient catalysts in higher plants is extremely challenging. Furthermore, its eight active sites are located in the interface of the large subunits, a feature which further complicates the understanding of the events occurring in the active sites responsible for Rubisco’s catalytic inefficiencies. While molecular dynamics (MD) simulations can be used to investigate these inefficiencies, previous studies are limited by a 50 ns time frame, thereby lacking the ability to adequately capture the underlying structural dynamics. For the first time, this thesis presents 17 long MD simulations, ranging from 500-1500 ns, using 13 different structures of Rubisco form I from three distinct organisms (Synechoccocus, spinach and Chlamydomonas). It provides evidence of the suitability of this technique in inspecting the impact of different mutants of Rubisco on the RuBP substrate’s binding affinity. For this purpose, results were compared to existing experimental data of mutant forms of Rubisco. The essays hereby reported demonstrate that, after long MD simulations of Rubisco, the resulting binding affinity ranking of the substrate to different mutants is consistent with previous experimental work. Moreover, the simulations reveal an allosteric behaviour of the substrate binding between the eight active sites of Rubisco, and verify the influence of Rubisco’s structural elements on the binding affinity of its substrate.

In this diploma work changes of initial and total activities and content of Rubisco in beech and Norway spruce were studied. The plants were cultivated in conditions with ambient CO2 concentration (350 mol·mol–1) and elevated CO2 concentration (700 mol·mol–1). Three series of samples (at the beginning, in the middle and at the end of growing season) were taken. Initial and total Rubisco activities were measured spectrophotometrically and activation state was calculated. Rubisco content was determined by SDS–PAGE method. Rubisco activity in beech cultivated in elevated CO2 concentration decreased during the whole growing season while in beech growing in ambient CO2 concentration Rubisco activity decreased up to middle of growing season and then increased. Rubisco content in beech in ambient CO2 concentration slightly increased and in beech in elevated CO2 concentration decreased up to middle of growing season and then increased. Rubisco activities in Norway spruce both in ambient and elevated CO2 concentration decreased. Rubisco content in Norway spruce in ambient CO2 concentration decreased but in Norway spruce in elevated CO2 concentration first decreased and then increased.

Made available in DSpace on 2016-04-28T19:58:54Z (GMT). No. of bitstreams: 1 Guilherme Sardas.pdf: 756009 bytes, checksum: 53ce6a4aaaedce44ff2bbdda33b56e3b (MD5) Previous issue date: 2014-10-31
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Many short stories of Murilo Rubião (1916-1991) bring actions and situations generally perceived as absurd, which analyzed thoroughly, can be considered representations of the feeling of estrangement of man in the world and the emptying of meaning of modern experience. The critics often associate the fantastic typical of the author to the category of absurd. But what characterizes the absurd universe created by Rubião? This research aims to investigate the construction of the absurd in work of Rubião, both thematically and discursive. The theoretical basis for this work is the absurd philosophy, present in the essay The myth of Sisyphus, by Albert Camus, and some ideas and concepts of Jean-Paul Sartre s existentialism. Considering this, we seek to demonstrate how is the dialogue between the short stories of Rubião and the absurd according thoughts of these philosophers of existence. Parallel to the study of this theme on construction of the absurd by Rubião, will seek to analyze the use of the tools of language to create this absurdity or, in other words, the creation of a poetic of the absurd in writing of the author. While the absurdity of Rubião dialogues with ideas of the philosophy of existence, it has also important differences in some points of the dramatic content of existential and existentialist literature, presenting ironic, comic and fantastic forms. Analyze how Murilo Rubião demarcates the peculiarities of its absurdity and the relations of this absurdity with the procedures of the modern fantastic are also motivations of this research
Muitos contos do escritor mineiro Murilo Rubião (1916-1991) trazem ações e situações entendidas, no geral, como absurdas que, analisadas de forma mais detida, são representações do sentimento de estranhamento do homem diante do mundo e do esvaziamento de sentido da experiência moderna. São narrativas que levam a crítica especializada a associar o fantástico típico do autor à adjetivação ou categoria do absurdo. Mas, o que caracteriza e para onde aponta o universo absurdo criado por Rubião? Esta dissertação visa investigar a construção do absurdo na obra muriliana, tanto no âmbito temático, quanto discursivo. Elegendo como base teórica a filosofia do absurdo de Albert Camus, presente no ensaio O mito de Sísifo, além de algumas ideias e conceitos existencialistas de Jean-Paul Sartre, buscaremos apontar um possível diálogo entre os contos de Rubião e o absurdo de Sartre. Paralelamente ao estudo dessa construção temática do absurdo em Rubião, realizamos uma análise da linguagem nesse processo criativo - ou, em outras palavras, como é construída uma poética do absurdo na escrita do autor. Ao mesmo tempo em que o absurdo de Rubião dialoga com ideias da filosofia da existência, também se afirma como componente de uma obra autêntica, que destoa em alguns pontos do teor dramático da literatura existencial e existencialista, apresentando-se como formas irônicas, cômicas e fantásticas. Analisar Murilo Rubião nas peculiaridades do absurdo poético bem como suas relações com os procedimentos do fantástico moderno serão também motivações de nossa pesquisa

A tese tem como objeto os pontos de contato entre a obra de Franz Kafka e a produção de dois autores brasileiros, Murilo Rubião e Aníbal Machado. Além de tentar assinalar em linhas gerais o que a crítica já salientou como essencial sobre as relações entre o universo de cada um dos escritores, o trabalho procura levantar aspectos novos que até certo ponto contrariam consensos, como, por exemplo, a suposta ausência do lirismo de Kafka, o recurso a uma linguagem rebuscada e ao fantástico por parte de Murilo Rubião, o surrealismo de Aníbal Machado. Destacam-se, ainda as convergências biográfico-sociais existentes entre os três. Tendo como eixo a figura do prosador tcheco, propõe-se que a literatura comparada é um exercício importante de análise, porém relativo, donde sua potência, necessidade e, paradoxalmente, sua fragilidade. Os três autores, a despeito de terem sido objeto de diversos estudos (em graus distintos de aprofundamento), suscitam no pesquisador de suas obras relativo cansaço frente ao volume de formulações repetidas a respeito deles, de modo que a comparação entre eles pode elucidar características isoladas. Defende-se, por fim, elegendo como ferramenta indispensável os textos literários, que uma compreensão da literatura como sistema que interage com outros sistemas é uma solução metodológica que legitima a comparação de quaisquer autores.