Submitted by Maike Costa (maiksebas@gmail.com) on 2017-09-20T12:52:54Z No. of bitstreams: 1 arquivototal.pdf: 1155001 bytes, checksum: c813651173e6bf037a98328b32bc7d5a (MD5) / Made available in DSpace on 2017-09-20T12:52:54Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1155001 bytes, checksum: c813651173e6bf037a98328b32bc7d5a (MD5) Previous issue date: 2016-10-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the thirties of the last century, several formal versions for the intuitive notion of algorithmic function were offered. Among them, the version of the recursive functions and the version of the Turing-computable functions. Posteriorly, such versions were extended in order to also include the partial algorithmic functions, giving rise, in this way, to the version of the partial recursive functions and to the version of the partially Turing-computable functions. In this context, this research, located into Computability Theory domain and built in the light of theoretical assumptions of Davis (1982), Mendelson (2009), Dias & Weber (2010), Rogers (1987), Soare (1987), Cooper (2004), among others, is intended to rebuild the proof that the given formal versions referred to the intuitive notion of partial algorithmic function, despite being conceptually distinct, they are extensionally equivalents in the sense that they determine the same set of theoretical-numerical functions. As a part of this rebuilding, we shall prove, in na unprecedented way, using quintuples, that every partial recursive function is partially Turing-computable. In the literature, this theorem is proved by means of a set of quadruples. However, defining a lower cardinality set constructed by quintuples, it is possible to prove it in a smaller time interval, which representes a gain from the computational point of view. Besides presenting this alternative proof, posed by the Church-Turing thesis that the set of partial recursive functions includes all the partial algorithmic functions, we shall investigate if this set itself and its infinite subsets are or are not algorithmic. In this survey, we shall demonstrate, in arithmetical terms, with the aid of Rice‟s theorem, that although the set of partial recursive functions is algorithmic, all its subsets which are different from the empty set are not, among which are the set of recursive functions and the set of primitive recursive functions. / Na década de 30 do século passado, foram oferecidas várias versões formais para a noção intuitiva de função algorítmica. Dentre elas, a versão das funções recursivas e a versão das funções Turing-computáveis. Posteriormente, tais versões foram estendidas a fim de abranger também as funções parciais algorítmicas, dando origem, deste modo, à versão das funções parciais recursivas e à versão das funções parcialmente Turing-computáveis. Nesse contexto, esta pesquisa, situada dentro do domínio da Teoria da Computabilidade e construída à luz dos pressupostos teóricos de Davis (1982), Mendelson (2009), Dias e Weber (2010), Rogers (1987), Soare (1987), Cooper (2004), entre outros, destina-se a reconstruir a prova de que as referidas versões formais dadas para a noção intuitiva de função parcial algorítmica, apesar de conceitualmente distintas, são extensionalmente equivalentes no sentido de que elas determinam o mesmo conjunto de funções numéricas. Como parte desta reconstrução, provaremos, de modo inédito, mediante o uso de quíntuplas, que toda função parcial recursiva é parcialmente Turing-computável. Na literatura especializada, esse teorema é provado por meio de um conjunto de quádruplas. Porém, definindo um conjunto de menor cardinalidade constituído por quíntuplas, é possível prová-lo em um intervalo menor de tempo, o que representa um ganho do ponto de vista computacional. Além de apresentar essa prova alternativa, posto pela Tese de Church-Turing que o conjunto das funções parciais recursivas contém todas as funções parciais algorítmicas, investigaremos se ele próprio e os seus infinitos subconjuntos são ou não algorítmicos. Nesta investigação, demonstraremos, em termos aritméticos, com o auxílio do Teorema de Rice, que embora o conjunto das funções parciais recursivas seja algorítmico, todos os seus subconjuntos diferentes do conjunto vazio não o são, dentre os quais estão o conjunto das funções recursivas e o conjunto das funções recursivas primitivas.

This work approaches the influence of the rice taxes behavior in Argentina, Brazil and Uruguay in the commercial flows of the production and the consumption of the grain in the region after Mercosul has been created. The main objectives are to evaluate the importance and the current systematics in the international trade of the cereal, as well as find exporting alternatives for the rice produced in Mercosul to third markets. At a first moment, this study analyzes since Mercosul s creation, moment when each one of the country-members already invigorated democratic regimes. After that, this study debates regionalism and multilateralism, to demonstrate that Mercosul s ideals, in last analysis, walk for the globalization. In the sequence, it approaches the panorama of international rice market, including the problematic of the rice subsidies in developed countries. The work advances to analyze the cereal price, which recently had incremented its value, as much in Brazil, as in the whole world, caused by an approach between offers and consumption of the grain, causing reduction of the supplies. After, it studies the possible consequences of the lack of harmonization of the rice taxes in the Brazilian domestic market, in view of the fiscal war , as in the country-members of the Mercosul, pointing as the oscillations taxes modify the members commercial flows and their competitiveness. Finally, this work concludes that the harmonization tax consists in one of the gaps that still lack to be filled to deep the integration relations, what it becomes the Mercosul a still embryonic integration process that needs constant development to reach objectives signed in the Treaty of Asuncion. / Este trabalho aborda a influência do comportamento da tributação do arroz na Argentina, Brasil e Uruguai nos fluxos comerciais da produção e do consumo do grão da região após a instituição do Mercosul. Os objetivos principais são avaliar a importância e a sistemática atual que se configura no comércio internacional do cereal, bem como apurar alternativas de escoamento do arroz do Mercosul a terceiros mercados conjuntamente. Para tanto, em um primeiro momento, este estudo analisa e contextualiza o período de formação do Mercosul, momento em que já vigoravam regimes democráticos de governo em cada um dos paísesmembros. Em seguida, estabelece-se um breve debate entre regionalismo e multilateralismo, demonstrando que os ideais mercosulinos, em última análise, caminham em favor da globalização. Na seqüência, aborda-se o panorama arrozeiro internacional, incluindo a problemática dos subsídios fornecidos pelos países desenvolvidos ao seu arroz. Adiante, trata-se do preço do cereal, o qual recentemente teve incremento em seu valor, tanto no Brasil, como no resto do mundo, em razão da aproximação entre oferta e consumo do grão, acarretando diminuição dos estoques. Após, procura-se apontar os possíveis reflexos da falta de harmonização da cadeia tributária do arroz tanto no mercado interno brasileiro, tendo em vista a guerra fiscal , como nos países-membros do Mercosul, apontando como as oscilações tributárias alteram os fluxos comerciais orizícolas dos países pertencentes ao bloco regional e, consequentemente, a competitividade desses. Por fim, conclui-se que a harmonização tributária constitui-se em uma das lacunas que ainda faltam ser preenchidas para o aprofundamento das relações integracionistas, o que torna o Mercosul um processo ainda embrionário de integração que necessita de desenvolvimento constante para atender os objetivos firmados pelo Tratado de Assunção.

Le virus de la panachure jaune du riz (virus RYMV pour Rice Yellow Mottle Virus) infecte principalement le genre Oryza et provoque d'importants dégâts sur les cultures de riz en Afrique. Bien que son génome soit rudimentaire, ce virus code des protéines essentielles pour son maintien chez l’hôte en dépit des mécanismes de défense de la plante. Les travaux récents de l’équipe ont permis d’identifier la protéine P1 codée par ce virus comme une protéine qui pourrait, grâce à sa propriété de suppresseur de RNA silencing, permettre au virus de contourner un mécanisme de défense essentiel de l’hôte et permettre au virus de perpétuer son cycle viral. Peu de données concernant les mécanismes d’action de la protéine P1 sont disponibles à ce jour. Le travail entrepris au cours de ma thèse a donc consisté à compléter les connaissances sur la biochimie de cette protéine, à définir sa structure tridimensionnelle et à mettre à jour sa localisation sub cellulaire afin de révéler des propriétés qui pourraient nous permettre non seulement de mieux comprendre comment cette protéine opère ses fonctions mais également de définir des méthodes de lutte adéquates contre ce virus. Ainsi, je montre que la protéine P1 constitue une nouvelle famille de protéine à doigt de zinc possédant une structure 3D inédite composée d’un premier domaine impliqué dans la dimérisation de la protéine et dans des interactions avec des ligands dont certains pourraient provenir de la plante hôte. Mon travail permet également d’identifier un deuxième domaine senseur de l’état redox au sein de la protéine qui lui permet probablement de sonder l’état de la plante pendant l’infection virale et d’adapter ses conformations pour assurer ses fonctions. Finalement, une approche par mutagénèse sur la protéine P1 assistée par la nouvelle structure 3D démontre qu’il est désormais possible d’identifier les résidus essentiels à la protéine pour sa participation dans l’infection virale. Ce travail ouvre donc de nombreuses perspectives pour de futures études de mécanistique sur ces domaines-clé de la protéine, ainsi que pour des études sur sa diversité génétique au sein des très nombreux isolats du virus RYMV en Afrique. / The virus of rice yellow mottle virus (RYMV for Rice Yellow Mottle Virus) mainly infects the genus Oryza and causes significant damage to rice crops in Africa. Although its genome is rudimentary, this virus code essential proteins for its maintenance in the host despite the defense mechanisms of the plant. Recent work by the team has identified the P1 protein encoded by the virus as a protein that could, through its ownership of RNA silencing suppressor, allow the virus to bypass an essential defense mechanism of the host and allow the virus to perpetuate its viral cycle. Little data on the mechanisms of action of the P1 protein is available to date. The work undertaken during my thesis was therefore to supplement the knowledge of the biochemistry of this protein, to define its three-dimensional structure and update its sub cellular localization to reveal properties that could enable us not only to understand how this protein works its functions but also to define methods of adequate response against the virus. Thus, I show that the P1 protein is a new zinc finger protein family having a unique 3D structure consisting of a first domain involved in the dimerization of the protein and in interactions with ligands some of which may originate from the plant host. My work also identifies a second sensor field in the redox state of the protein that probably allows him to probe the state of the plant during viral infection and adapt its conformation to conduct their duties. Finally, a mutagenesis approach to P1 assisted by the new 3D protein structure shows that it is now possible to identify critical residues in the protein for its participation in the viral infection. This work thus opens up many possibilities for future mechanistic studies on these key areas of the protein, as well as for studies of genetic diversity within many RYMV isolates of virus in Africa

Rice have highly derived florets borne on a short branch called ‘spikelet’ comprised of a pair of rudimentary glumes and sterile lemma (empty glumes) that subtends a single fertile floret. The floral organs consist of a pair of lodicules, six stamens and a central carpel that are enclosed by a pair of bract-like organs, called lemma and palea. A progressive reprogramming of meristem identity during the floral development of flowers, on branches on the inflorescence, is correlated with changes in transcriptional status of regulatory genes that execute cascades of distinct developmental events. On the other hand phytohormones such as auxin and cytokinin that are critical in predetermining the sites of new organ primordia emergence and in maintaining the size or populations of meristems. Molecular genetic analyses of mutants have expanded the repository of genes regulating floral organ specification and identity, yet the finer mechanistic details on process downstream to these regulatory genes and co-ordination with phytohormone signalling pathways needs further investigation. One aim of the study presented in this thesis is to develop a tool that would display of spatial description of dynamic auxin or cytokinin accumulation in developing rice inflorescence and floral meristems and to evaluate auxin distribution defects of OsMADS1-RNAi florets using this tool. Additionally, we aim to understand the regulatory effects on OsMADS1 on candidate floral organ and meristem fate determining genes during two temporal phases of flower development to decipher other regulatory cascades controlled by OsMADS1. Spatial distribution profile of phytohormones in young and developing meristems of rice Cytokinin promotes meristem activity (Su et al., 2011) while auxin accumulation, directed by auxin efflux transport PIN proteins predicts sites of new organ initiation (Reinhardt et al., 2003; van Mourik et al., 2012). Previous studies in the lab deciphered that OsMADS1 exerts positive regulatory effects on genes in auxin pathways and repressive effects on cytokinin signaling and biosynthetic genes (Khanday et al., 2013). Thus, the need for a reliable system to understand auxin and cytokinin activity in live inflorescence and floral meristems of rice motivated us to raise promoter: reporter tools to map the spatial and temporal phytohormone distribution. Confocal live imaging conditions in primary roots of IR4DR-GFP and DR5-CyPet lines was performed and responsiveness of the DR5 elements to auxin was authenticated. Auxin maxima were distinctly seen in the epidermal and sub-epidermal cells of inflorescence branch primordia anlagen and apices of newly emerged branch primordia. As floral organs were being initiated, on the floret meristem, we discerned the sequential appearance of auxin accumulation at sites of organ primordia while apices of early floral meristems (FM) showed low auxin content. We clearly detect canalization of auxin streams marking regions of vascular inception. Using this live imaging system we probed auxin patterns and levels in malformed and indeterminate OsMADS1-RNAi florets and we observed a significant reduction in the levels of auxin. Two oppositely positioned peaks of auxin were noted in the persistent FM of OsMADS1-RNAi florets, a pattern similar to auxin dynamics at sites of rudimentary glume primordia on the wild-type (WT) spikelet meristem. These studies were followed up with immunohistochemistry (IHC) on fixed tissues for “PIN” transport proteins that suggest PIN convergence towards organ initiation sites, regions where auxin accumulation was clearly visualized by the IR4DR5-GFP and DR5-CyPet reporters. IHC experiments that detected GFP, in fixed tissues of TCSn-mGFP ER (WT) and TCSn-mGFP ER;OsMADS1-RNAi (OsMADS1-RNAi) inflorescence and florets showed an ectopic increase in the domain of cells with cytokinin response in OsMADS1-RNAi florets, compared to that of WT. Intriguingly, cytokinin responsive cells persisted in the central FM of OsMADS1-RNAi florets that might partially account for some of the FM indeterminacy defects seen in these florets. A correlative observation of these different imaging data hint at some exclusive patterns of the IR4DR5/DR5 and TCSn reporters that in turn lead us to speculate that a cross talk between auxin and cytokinin distribution may contribute to the precise phyllotaxy of lateral organs in rice inflorescence. Studies on novel targets of OsMADS1 in floral organ identity and meristem determinacy Loss of OsMADS1 function results in rice florets with miss specified floral organs and an indeterminate carpel produces new abnormal florets. Despite having several mutants in OsMADS1, mechanisms of how OsMADS1 regulates meristem maintenance and termination is not well understood. Global expression profile in OsMADS1-RNAi vs. WT tissues encompassing a wide range of developing florets (0.2 to 2cm panicles), gave an overview of OsMADS1 functions in many aspects of floret development. Here, a gene-targeted knockout of OsMADS1 named - osmads1ko (generated in a collaborative study) was characterized and found to display extreme defects in floral organs and an indeterminate FM. Strikingly, in addition to loss of determinacy, FM reverts to a prior developmental fate of inflorescence on whose new rachis are leaf-like malformed florets. We suggest these phenotypes reflect the null phenotype of OsMADS1 and its role in meristem fate maintenance. We tested gene expression levels for some proven targets of OsMADS1 (Khanday et al., 2013) and utilized panicles in two developmental phases- young early FMs (panicles of 0.2 to 0.5 cm) and older florets with organ differentiation (panicles of 0.5 to 1cm). We observed temporally different effects on the regulation of OsMADS34 that together with histology of young osmads1ko inflorescences suggest that the mutant is impeded for spikelet to floral meristem transition. In addition, OsMADS1 had a positive regulatory effect on genes implicated for lemma and palea organ identity such as OsIDS1, OsDH1, OsYABBY1, OsMADS15, OsMADS32, OsDP1 and OsSPL16 in both young and old panicles while OsIG1 was negatively regulated in both phases of development. MADS-box genes important for carpel and ovule development - OsMADS13 and OsMADS58 were had significantly reduced expression in florets undergoing organ differentiation. OsMADS1 positively regulated several other non MADS-box developmental genes - OsSPT, OsHEC2 and OsULT1, whose Arabidopsis homologs control carpel development and FM determinacy. These genes are de-regulated in later stages of osmads1ko floret development and are unaffected in younger panicles. Finally, OsMADS1 continually activated meristem maintenance genes - OsBAM2-like and OsMADS6 while the activation of OSH1 in early floral meristems was later altered to a repressive effect in developing florets. Perhaps such dynamic temporal effects on meristem genes are instrumental in the timely termination of the floral meristem after floral organ differentiation. More importantly, we show that regulation of many of these genes is directly affected by OsMADS1, through our studies on expression levels before and after chemical induction of OsMADS1-GR protein in amiRNAOsMADS1 florets. Further, some key downstream targets were re-affirmed by studying expression status in transgenic lines, with the OsMADS1-EAR repressive protein variant. These results provide new insights into the developmentally phased roles of OsMADS1 on floral meristem regulators and determinants of organ identity to form a determinate rice floret. Gene networks regulated by OsMADS1 during early flower development To identify global targets in early floret meristems, we determined the differential RNA transcriptome in osmads1ko tissues as compared to wild-type tissues. These data revealed regulators of inflorescence architecture, floral organ identity including MADS-box floral homeotic factors, factors for meristem maintenance, auxin response, transport and biosynthesis as some of the important functional classes amongst the 2725 differentially expressed genes (DEGs). Integrating DEGs with OsMADS1 ChIP-seq data (prior studies from our lab) we deciphered direct vs. indirect and positive vs. negatively regulated targets of OsMADS1. These datasets reveal an enrichment for functional categories such as metabolic processes, signaling, RNA transcription and processing, hormone metabolism and protein modification. Using Bio-Tapestry plot as a tool we present a visualization of a floral stage-specific regulatory network for genes with likely functional roles in meristem specification and in organ development. Further, to examine if indirect targets regulated by OsMADS1 could be mediated through transcription factors (that are themselves direct targets), we constructed a small network with the transcription factors OSH1, OSH15 and OsYABBY1 as key nodal genes and we predicted their downstream effects. Taken together, these analyses provide examples of the complex networks that OsMADS1 controls during the process of rice floret development. In summary, we surmise that defect in phytohormone distribution in OsMADS1 knockdown florets results in irregular patterns of lateral organ primordia emergence. In addition, the derangements in the developmentally stage specific expression of floral meristems identity and organ identity genes culminates in miss-specified and irregularly patterned abnormal organs in Osmads1 florets. Thus, our study highlights the versatility of OsMADS1 in regulating components of hormone signaling and response, and its effects on various floral development regulators results in the formation of a single determinate floret on the spikelet. References: Khanday I, Yadav S.R, and Vijayraghavan U. (2013). Plant Physiol 161, 1970–1983. van Mourik S , Kaufmann K, van Dijk AD, Angenent G.C, Merks R.M.H, Molenaar J. (2012). PLOS One 1, e28762 Reinhardt D, Pesce E, Stieger P, Mandel T, Baltensperger K, Bennett M, Traas J, Friml J and Kuhlemeier C. (2003). Nature 426, 255-260 Su Y, Liu Y and Zhang X. (2011) Mol Plant 4, 616–625

No description available.

In dieser Arbeit wurden Ergebnisse einer Analyse der elektronischen Struktur in Sr2CuO2Cl2 mittels winkelaufgelöster Photoemission dargelegt. Sie betreffen i) Sr2CuO2Cl2 als Untersuchungsgegenstand für die Grundlagenforschung an Hochtemperatursupraleitern (HTSL), ii) winkelaufgelöste Photoemission als Untersuchungsmethode zur Messung der elektronischen Struktur von HTSL und deren Muttersubstanzen, iii) Eigenschaften der elektronische Anregungen in Sr2CuO2Cl2 in unmittelbarer Nähe des chemischen Potenzials, sowie iv) das durch Korrelationen stark beeinflusste Dotierungsverhalten der Kuprate. 1. Sr2CuO2Cl2 eignet sich Dank seiner exakten Stöchiometrie und der strukturell perfekten Kupfer-Sauerstoff Ebenen hervorragend als Untersuchungssubstanz für die isolierende Phase der HTSL. 2. Mittels winkelaufgelöster Photoemission ist es möglich, die k-Raum- und Energieverteilung (Dispersion) von Anregungen nahe des chemischen Potenzials in Sr2CuO2Cl2 auszumessen. Dabei wurde eine starke Abhängigkeit der Intensität des Photoemissionssignales in Abhängigkeit von der Photonenenergie beobachtet. Es konnte nachgewiesen werden, dass sich diese Intensitätsoszillationen mit hoher Wahrscheinlichkeit durch eine Bragg-Interferenz der Photoelektronenewelle an der Schichtstruktur von Sr2CuO2Cl2 erklären und weiterhin, dass die gemessenen Dispersionskurven, von einer willkürlichen Normierung der Intensität abgesehen, unabhängig von der verwendeten Photoenenenergie sind. 3. Die Photoemissionsspektren von Sr2CuO2Cl2 zeigen die für Ladungstransfer-Isolatoren charakteristische Aufteilung des spektralen Gewichts (der besetzten Elektronenstruktur) in ein unteres Hubbardband, bindende und nichtbindende Sauerstoffbänder und der ZR-Singlet Struktur. Dabei konnte das untere Hubbardband identifiziert werden durch seine durch Resonanz hervorgerufene Intensitätsverstärkung (und dem daraus resultierenden d8-Charakter dieser Struktur), die Sauerstoffbänder und die ZR-Singlet Struktur durch eine Analyse ihres Symmetrieverhaltens unter Berücksichtigung der Polarisationsabhängigkeit des Photoemissionssignales. Das ZR-Singlet besitzt eine a1g-Symmetrie was sowohl die Konstruktion des ZR-Singlets nach Zhang und Rice als auch die Ergebnisse der Diagonalisierung der isolierten, mit zwei Löchern besetzten Plakette bestätigt. 4. Die Dispersion des ZR-Singlets ist parabolisch entlang Gamma-(Pi,Pi) mit einem absoluten Bindungsenergieminimum bei (0.5Pi,0.5Pi) und parabolisch entlang Gamma-(Pi,0) mit einem lokalen Bindungsenergieminimum bei (0.7Pi,0). Die Bandbreite entlang dieser beiden Richtungen beträgt etwa 300 meV beziehungsweise 200 meV, der Abstand der beiden minimalen Bindungsenergien entlang dieser Richtungen ist 72 meV. Das Spektralgewicht des ZR-Singlets ist keilförmig verteilt mit einem Maximum bei (0.5Pi,0.5Pi) und (0.7Pi,0), also jeweils in unmittelbarer Nähe der minimalen Bindungsenergien dieser Struktur. Es verschwindet bei Gamma und (Pi,Pi), hat jedoch einen endlichen Wert bei (Pi,0). Der Vergleich dieser Resultate favorisiert das erweiterte t-J-Modell zur Beschreibung der Dynamik des ZR-Singlets. Insbesondere i) die parabolische Dispersion des ZR-Singlets entlang Gamma-(Pi,Pi), ii) der geringe aber endliche energetische Abstand der Bindungsenergie-Minima entlang Gamma-(Pi,Pi) und Gamma-(Pi,0) und iii) die keilförmige Verteilung des Spektralen Gewichts entlang Gamma-(Pi,0) sind die experimentellen Indizien dafür. / A detailed ARPES study of the low binding-energy occupied electronic structure of Sr2CuO2Cl2 has been done. It corresponds to an investigation of the first electron-removal states of an undoped CuO2-plane: 1. The photoemission signal of the first electron-removal states at both (0.5Pi,0.5Pi) and (0.7Pi,0) exhibits a marked photon-energy dependence. The intensity profile shows strong oscillations with maxima near 16, 25, 35 and 49 eV, corresponding to final state crystal momenta kperp=0.82, 1.63, 2.40 and 3.12 A-1. 2. Along the high-symmetry directions Gamma-(Pi,Pi) and Gamma-(Pi,0) the first electron-removal states shows a strong polarization dependence. This can be linked to the strongly polarization-dependent matrix element, which in turn allows the determination of the symmetry of the first electron-removal state itself. For both high-symmetry directions we observe a polarization dependence in keeping with that expected for a Zhang-Rice singlet state in the framework of either a three-band or one-band model Hamiltonian. 3. Our data show that the dispersion of the first electron-removal states along both high symmetry directions (Gamma-(Pi,Pi) and Gamma-(Pi,0)) is parabolic-like and independent of the excitation energy. This, and the rather large difference in lowest binding energy of the first electron-removal state along these directions, shows the validity of the extended t-J model for describing the disperion relation of a single hole in an antiferromagnetic CuO2 plane. Thus, the inclusion of second (t2) and third (t3) neighbor hopping terms with realistic values of t2=-0.08 and t3=0.15 in units of the next neighbor hopping t=t1 are required. 4. Upon application of a simple fit procedure, we infer the momentum distribution of the spectral weight of the coherent and incoherent part of the first electron-removal state to have its maximum along Gamma-(Pi,Pi) at (0.5Pi,0.5Pi), being symmetrically suppressed away from this point. Along Gamma-(Pi,0) the spectral weights of both parts reach their maximum at (0.7Pi,0) and then drop fast. The ratio between the coherent and incoherent spectral weight is strongly photon-energy dependent, which, at first sight would appear to violate the physics of the spectral function: (i) the necessity for a more sophisticated framework in which to analyse the weight of the coherent and incoherent contributions to the spectral weight (ii) significant (hn-dependent) intensity due to extrinsic processes (iii) intensity in this energy region due to intrinsic electronic states other than the Zhang-Rice singlet.

Many people around the world live in islands with mountainous lands. These people plant upland rice for their staple food. However, farming in these disadvantageous farms requires high input and gains low yield. One possible solution for improving productivity is by utilizing precision seeding. This study is focused on developing a robot for precision seeding of rice that is suitable for farming in rough terrain. A bioinspired human arm robot for picking seeds and making a hole on the ground was developed in accordance with Aalborg method for bioinspired design. Development of a mobile platform to carry the robot arm was done using hybrid wheel and leg (wheg) wheels and skid steering locomotion. The NugalBot could climb obstacle and perform precision rice seed singulation. However, the performance of the mechanisms for making hole and for covering the hole was dependent on the hardness of the soil.

No description available.

LD2668 .T4 1954 P47 / Master of Science

Call number: LD2668 .T4 1985 K87 / Master of Science / Agronomy