Retroviruses are viruses which are able to integrate to genome of host cell. Nonrandom integration of provirus near or inside some cellular genes may result in their deregulation, activation or silencing. This can later lead to cell transformation and tumor formation. This thesis discusses identification of viral integration sites (VIS) and common integration sites (CIS) in tumors originating from different organs (mostly kidneys, lungs and liver) with using mostly avian retroviruses subgroup J, specifically first natural isolate HPRS-103 and laboratory made virus MAV-J, which was made by replacing gene envB by envJ. Infection was made in ovo using chicken breeds Brown Leghorn and White Leghorn and tumors were isolated from 8 to 28 weeks after infection. For molecular analyses was used inverse PCR method and sequencing. From 74 molecularly analyzed tumors there was detected 373 VIS and 6 CIS with statistical significance over 2.10-2 . Gene with the highest number of hits was FRK (14 times), then TERT (5 times), CTDSPL (5 times), EGFR/ERBB1 (3 times), MYB (3 times) and MYC (3 times). Except 6 CIS there were other genes found, which had smaller statistical significance. Keywords: retrovirus, insertional mutagenesis, subgroup J, oncogenesis, oncogenes, MAV-J, HPRS-103, proviral integration sites, tumors

Made available in DSpace on 2015-04-14T14:48:29Z (GMT). No. of bitstreams: 1 389628.pdf: 186071 bytes, checksum: 68b365e4a74a86424538dd8a1e43c80d (MD5) Previous issue date: 2007-03-26 / Este trabalho foi desenvolvido na linha de pesquisa Pol?tica Criminal, Estado e Limita??o do Poder Punitivo, tendo como objetivo investigar a possibilidade de aperfei?oamento e legitima??o do Tribunal do J?ri, mantendo-o como a institui??o que reafirma o Estado Democr?tico de Direito. Partindo da an?lise do Tribunal do J?ri em seus aspectos hist?ricos e sociol?gicos e de direito comparado, e abordando como ele ? tratado pela doutrina processual penal no Brasil, a pesquisa aponta a defici?ncia atual e a perda da identidade da institui??o. Revela ainda os limites das propostas de reforma procedimental em tramita??o no Congresso Nacional: Por meio da pesquisa de campo, com aplica??o de question?rio, os membros do Conselho de Senten?a questionados, sob os mais variados pontos relevantes ao Tribunal do J?ri e sua fun??o, demonstraram ter dificuldade em compreender o significado do julgamento, os princ?pios constitucionais e at? do seu papel como julgadores, podendo, seu veredicto representar uma injusti?a. Com o objetivo de melhor julgar ? preciso que reformula??es se concretizem visando a evitar que as raz?es da exist?ncia do J?ri percam o sentido e acabem por desvirtu?-lo, em desprest?gio dos princ?pios constitucionais. Desse modo, conclui-se que o Tribunal do J?ri somente alcan?ar? sua meta de julgar o semelhante com justi?a, se o jurado estiver alicer?ado de todas as garantias constitucionais, ps?quicas, e amparado nos princ?pios da dignidade da pessoa humana e da liberdade de ser escolhido e de escolher o destino de quem estar? sob seu senso de justi?a.

Quasars are valuable sources for several cosmological applications. In particular, they can be used to trace some of the heaviest halos and their high intrinsic luminosities allow them to be detected at high redshifts. This implies that quasars (or active galactic nuclei, in a more general sense) have a huge potential to map the large-scale structure. However, this potential has not yet been fully realized, because instruments which rely on broad-band imaging to pre-select spectroscopic targets usually miss most quasars and, consequently, are not able to properly separate broad-line emitting quasars from other point-like sources (such as stars and low resolution galaxies). This work is an initial attempt to investigate the realistic gains on the identification and separation of quasars and stars when medium- and narrow-band filters in the optical are employed. The main novelty of our approach is the use of Bayesian priors both for the angular distribution of stars of different types on the sky and for the distribution of quasars as a function of redshift. Since the evidence from these priors convolve the angular dependence of stars with the redshift dependence of quasars, this allows us to control for the near degeneracy between these objects. However, our results are inconclusive to quantify the efficiency of star-quasar separation by using this approach and, hence, some critical refinements and improvements are still necessary. / Quasares são objetos valiosos para diversas aplicações cosmológicas. Em particular, eles podem ser usados para localizar alguns dos halos mais massivos e suas luminosidades intrinsecamente elevadas permitem que eles sejam detectados a altos redshifts. Isso implica que quasares (ou núcleos ativos de galáxias, de um modo geral) possuem um grande potencial para mapear a estrutura em larga escala. Entretanto, esse potencial ainda não foi completamente atingido, porque instrumentos que se baseiam no imageamento por bandas largas para pré-selecionar alvos espectroscópicos perdem a maioria dos quasares e, consequentemente, não são capazes de separar adequadamente quasares com linhas de emissão largas de outras fontes pontuais (como estrelas e galáxias de baixa resolução). Esse trabalho é uma tentativa inicial de investigar os ganhos reais na identificação e separação de quasares e estrelas quando são usados filtros de bandas médias e estreitas. A principal novidade desse método é o uso de priors Bayesianos tanto para a distribuição angular de estrelas de diferentes tipos no céu quanto para a distribuição de quasares como função do redshift. Como a evidência desses priors é uma convolução entre a dependência angular das estrelas e a dependência em redshift dos quasares, isso permite que a degenerescência entre esses objetos seja levada em consideração. Entretanto, nossos resultados ainda são inconclusivos para quantificar a eficiência da separação entre estrelas e quasares utilizando esse método e, portanto, alguns refinamentos críticos são necessários.

O objetivo desse estudo foi avaliar a eficiência do protocolo de pré-sincronização da ovulação com progesterona (P4) injetável de longa ação em novilhas e a influência de seus efeitos sobre a taxa de prenhez do protocolo de inseminação artificial em tempo fixo (IATF) J-Synch adaptado. Novilhas Nelore (n=638; 21,5±3,1 meses e 295±23,3 kg) foram classificadas por ultrassonografia nos D22 e D12 em púberes (presença de corpo lúteo (CL) no D22 e/ou D12) ou pré-púberes (ausência de CL em ambas avaliações) e receberam 150 mg de P4 de longa ação I.M. no D22 (tratadas) ou não (controle), perfazendo arranjo fatorial 2X2. No D12, apenas as novilhas tratadas, receberam 150 µg de D-cloprostenol (PGF, I.M.) e 1 mg de benzoato de estradiol (BE, I.M.). No D0, avaliou-se a ciclicidade das novilhas e todas foram sincronizadas de acordo com protocolo J-Synch adaptado: D0: dispositivo intravaginal de P4 (1 g) + 2 mg BE e 75 µg PGF; D6: remoção do dispositivo + 150 micro;g PGF. Uma detecção de estro foi realizada 48 h após a retirada dos dispositivos e as detectadas em estro foram inseminadas 12 h depois, ou em tempo fixo no D9, com aplicação I.M. de 10,5 µg acetato de buserelina. Exames ultrassonográficos foram realizados para mensurar o diâmetro do maior folículo e foi determinado um escore uterino (EU=1-6). O diagnóstico de gestação foi realizado no D39. Após 12 dias do tratamento (D0), menor proporção de novilhas, apresentando CL, foi verificada no grupo controle, quando comparada à de novilhas tratadas. Esta diferença foi mais acentuada nas pré-púberes (controle: 11,4% (23/199) vs. tratamento: 63,7% (136/215); P<0,0001), quando comparada às púberes (controle: 79,5% (92/113) vs. tratamento: 91,2% (102/111); P=0,002). A taxa de prenhez geral foi de 42,2% e tendeu a ser influenciada por tratamento (P=0,07). Novilhas do grupo controle apresentaram menor taxa de prenhez, de manifestação de estro 48 h após a retirada do dispositivo (P=0,02) e de ovulação antecipada (P=0,007), quando comparadas às novilhas tratadas (37,3% (119/312) vs. 44,7% (150/326); 15,9% (48/312) vs. 23,3% (52/224); 7,5% (23/258) vs. 15,4% (42/244), respectivamente). Para o diâmetro do folículo dominante, no momento da IATF (D9), houve interação entre status puberal e tratamento (P<0,05), sendo que as novilhas tratadas não diferiram entre si (pré-púberes: 11,1±0,13 mm vs. púberes: 11,1±0,17 mm; P=0,99). Para as novilhas do controle, as pré-púberes apresentaram menores diâmetros foliculares (10,9±0,13 mm), quando comparados aos das púberes (11,5±0,17 mm, P=0,03). A probabilidade de ciclicidade foi influenciada pelo diâmetro do folículo no D22 e no D12, para as novilhas pré-púberes tratadas (P<0,05). O uso da P4 aumentou o diâmetro folicular e o EU, no D12, para as novilhas pré-púberes tratadas, quando comparadas às controles (P<0,05). A taxa de prenhez foi maior nas novilhas que manifestaram estro 48 h após a retirada do dispositivo e foram inseminadas com 60h (60h: 66,1% (85/124); IATF: 34,8% (185/515)), e nas novilhas que apresentaram CL no D0 (com CL: 51,5% (181/353); sem CL: 30,5% (89/286)). Conclui-se que o protocolo de pré-sincronização com P4 injetável aumenta a porcentagem de novilhas ciclando e tende a aumentar a taxa de prenhez apresentada pelo protocolo J-Synch adaptado. / The objective of this study was to evaluate the effect of long-acting injectable progesterone (P4) pre-synchronization protocol and the influence of its effects on the pregnancy rate of the timed artificial insemination (TAI) J -Synch adapted protocol. Nelore heifers (n=638; 21.5±3.1 months and 295±23.3 kg) were classified by ultrasonography on D22 and D12 in pubertal (with corpus luteum (CL) on D22 and/or D12) or prepubertal (absence of CL in both evaluations), and received 150 mg of long-acting P4 I.M. on D22 (treatment) or not (control), making a factorial arrangement 2X2. On D12, only heifers treated with P4 received 150 µg of D-cloprostenol (PGF, I.M.) and 1 mg of estradiol benzoate (EB, I.M.). On D0, presence of CL was evaluated and all heifers were synchronized according to the adapted J-Synch protocol: D0: intravaginal release P4 device (1 g) + 2 mg EB and 75 µg PGF; D6: removal of the P4 device + 150 µg PGF. Animals detected in estrus at 48 hours after device removal were inseminated 12 h after or at fixed time on D9, with application of 10,5 µg buserelin acetate I.M. The largest follicular diameter was evaluated by ultrasound and was determined a uterine score (US= 1-6). The pregnancy diagnostic was performed on D39. After 12 days of treatment (D0), lowest proportion of heifers presenting CL was verified in control group, when compared to treated heifers. This difference was more pronounced in the prepubertal (control: 11.4% (23/199) vs. treatment: 63.7% (136/215); P<0,0001), when compared to pubertal (control: 79.5% (92/113) vs. treatament: 91.2% (102/111); P=0,002). The pregnancy rate was 42.2% and tended to be influenced by treatment (P=0.07). Control heifers had lower pregnancy rate, estrus manifestation 48 h after device remotion (P = 0.02) and early ovulation (P = 0.007), when compared to treated heifers (37.3% (119/312) vs. 44.7% (150/326); 15.9% (48/312) vs. 23.3% (52/224); 7.5% (23/258) vs. 15.4% (42/244), respectively). For diameter of the dominant follicle at TAI (D9) there was interaction between pubertal status and treatment (P<0,05), and the two treated groups did not differ (prepubertal: 11.1±0.13 mm vs. pubertal: 11.1±0.17 mm; P=0,99). For control heifers, follicular diameter was smaller for prepubertal (10.9 ± 0.13 mm) than for pubertal (11.5 ± 0.17 mm, P = 0.03). Probability of cyclicity was influenced by follicular diameter on D22 and D12, for treated prepubertal heifers (P <0.05). Use of P4 increased the follicular diameter and US on D12 for prepubertal heifers treated, when compared to controls (P <0.05). Pregnancy rates was greater in heifers that showed estrus 48 h after the device was removed and were inseminated with 60h (60h: 66.1% (85/124); TAI: 34.8% (185/515)), and in heifers with CL on D0 (with CL: 51.5% (181/353); without CL: 30.5% (89/286)). In conclusion, pre-synchronization protocol with long-acting P4 increases the percentage of cyclic heifers and tends to increase the pregnancy rate after J-Synch adapted protocol.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-10T14:08:07Z No. of bitstreams: 1 HernaniVeloso.pdf: 2733892 bytes, checksum: 47d4ac1052c3951cb8dcf6754030289e (MD5) / Made available in DSpace on 2017-08-10T14:08:07Z (GMT). No. of bitstreams: 1 HernaniVeloso.pdf: 2733892 bytes, checksum: 47d4ac1052c3951cb8dcf6754030289e (MD5) Previous issue date: 2017-01-16 / The present research subtends an analytical comparison between the Philosophy of education of Jean-Jacques Rousseau (1712-1778) and the LDBN - Law of Guidelines and Bases of National Education Nº 9.394 / 1996, as to the purpose of Basic Education that is the formation of citizenship. Therefore, this research presents as main categories of analysis: citizenship, the subject of citizenship from Rousseau's perspective and the realization of this ideal through school functionality as prescribed in LDB and NCPs. The bibliographical references of this research come from the works of Rousseau (1983, 1999, 2004), Dalbosco (2011), Vernant (2009), Descartes (1996), Fortes (1997), Freitas (2003), Pissarra (2002), Almeida Júnior (2009), which will guide discussions in the perspective of Philosophy; (1999), Pinsky & Pinsky, (2015), Delors (2012), Santos (2011), Dozol (2006) and other works and authors converging on the proposed theme. We will identify J-J Rousseau's criticism of the ideal of progress in the Enlightenment perspective as a course of deconstruction and moral reconstruction from the perspective of interiority, seducing by self-experience, informal knowledge of self in relation to things and men in the social realm. We will analyze the concept of citizenship, considering rights and duties as factors inherent to the formation of civil society, necessary for the process of globalization of citizenship in the perspective of solidarity and otherness, with J-J Rousseau's political philosophy as the guiding principle for the twenty-first century. We will investigate, therefore, under the eyes of Rousseau, the formation of citizenship from the LDB, considering approximations and distances with regard to public education and the formation of citizenship in the molds of Rousseau's thinking. In this sense, we seek, through this approach, a moral and political awareness of the elementary school student having as the target of the critical-philosophical view the transversality of Ethics as the school practice that is intended for the formation of citizenship. In order to contribute to the content of this analysis, will be adopted UEB "Senator Miguel Lins", which will be constituted as a locus and corpus for documentary and curricular analysis, taking into account the school space which is, together with the transversality of the Ethics, in one of the conditioning factors of its pedagogical practices. / Jean-Jacques Rousseau (1712-1778) e a LDBN – Lei de Diretrizes e Bases da Educação Nacional nº 9.394/1996, quanto a finalidade da Educação Básica que é a formação da cidadania. Para tanto, esta investigação apresenta como principais categorias de análise: a cidadania, o tema da cidadania na perspectiva de Rousseau e a concretização deste ideal através da funcionalidade escolar tal como está prescrito na LDB e nos PCN‟S. Os referenciais bibliográficos desta pesquisa partem das obras de Rousseau (1983, 1999, 2004), Dalbosco (2011), Vernant (2009), Descartes (1996), Fortes (1997), Freitas (2003), Pissarra (2002), Almeida Júnior (2009), que nortearão as discussões na perspectiva da Filosofia; também, Cambi (1999), Pinsky & Pinsky, (2015), Delors (2012), Santos (2011), Dozol (2006) e outras obras e autores convergentes no tema proposto. Identificaremos a crítica de J-J Rousseau ao idealA presente pesquisa subtende uma comparação analítica entre a Filosofia da educação de do progresso na perspectiva iluminista como um percurso de desconstrução e reconstrução moral sob a ótica da interioridade, sedimentando pela auto experiência, o conhecimento informal de si em relação às coisas e aos homens no âmbito social. Analisaremos o conceito de cidadania considerando os direitos e deveres como fatores inerentes à formação da sociedade civil, necessários ao processo de globalização da cidadania nas perspectivas da solidariedade e da alteridade, tendo como princípio norteador para o século XXI a Filosofia política de J-J Rousseau. Investigaremos, assim, sob o olhar de Rousseau, a formação da cidadania a partir da LDB, considerando aproximações e distanciamentos no que se refere à educação pública e a formação da cidadania nos moldes do pensamento rousseauniano. Nesse sentido, busca-se, por meio deste enfoque uma sensibilização moral e política do aluno do Ensino Fundamental tendo como o alvo do olhar crítico-filosófico a transversalidade da Ética como a prática escolar que se destina a formação da cidadania. A fim de contribuir com o teor desta análise, será adotado UEB “Senador Miguel Lins”, a qual se constituirá em locus e corpus para análises documentais e curriculares, levando ainda em consideração o espaço escolar o qual se constitui, juntamente com a transversalidade da Ética, em um dos fatores condicionantes de suas práticas pedagógicas.

Essa dissertação tem como objetivo apresentar uma medida de desigualdade distinta das usualmente utilizadas na literatura de desigualdade. Tal medida, aqui denominada índice J, além de possuir a característica de ser simétrica também possibilita conduzir análises distintas daquelas feitas com os índices usualmente utilizados. Para avaliar a aplicabilidade do índice J foram utilizados dados provenientes da PNAD referente aos anos de 2007, 2011 e 2015 . Apenas dados referentes ao estado de São Paulo foram incluídos. Além de avaliar a evolução da desigualdade no período, decomposição intra e entre grupos foram conduzidas. Testes de hipótese para a desigualdade entre grupos, uma das possibilidades apresentada pelo índice J, foram conduzidos. Também foi avaliado como a presença de erros de medidas não condicionais à renda influenciaria o resultado. Os resultados apresentados pelo índice J apontam para uma diminuição da desigualdade de renda no período analisado, sendo que a variável educação se apresentou como a característica com maior capacidade de explicar a desigualdade total a partir da desigualdade entre grupos, dentre as variáveis analisadas. A simulação de Monte Carlo conduzida para o teste de hipótese para desigualdade entre grupos também apontou à variável educação como a mais provável de gerar desigualdade. A presença de erros de medida não condicionais à renda não influenciou no resultado final do índice J, porém a simulação de tais erros contribuiu para amenizar o problema de discretização dos dados provenientes da PNAD. O índice J apresentou-se como uma alternativa viável aos índices usualmente utilizados na literatura de desigualdade, possibilitando algumas análises distintas e que podem auxiliar no estudo da desigualdade de renda. / This dissertation aims to present a measure of inequality distinct from those usually used in the inequality literature. Such a measure, here called the J index, besides having the characteristic of being symmetrical also makes it possible to conduct analyzes different from those made with the indexes usually used. To evaluate the applicability of the J index, data from the PNAD for the years 2007, 2011 and 2015 were used in the analysis. Only data referring to the state of São Paulo were included. In addition to assessing the evolution of inequality in the period, within and between group decomposition were conducted. Hypothesis tests for the inequality between groups, one of the possibilities presented by the index J, were conducted. It was also evaluated how the presence of errors of measures not conditional to the income would influence the result. The results presented by the index J point to a decrease in income inequality in the analyzed period, with the education variable being the characteristic with the greatest capacity to explain the total inequality from the inequality between groups, among the variables analyzed. The Monte Carlo simulation conducted for the hypothesis test for inequality between groups also pointed to the education variable as the most likely to generate inequality. The presence of measurement errors did not influence the final result of the J index, but the simulation of such errors contributed to soften the problem of discretization of PNAD data. The index J was presented as a viable alternative to the indexes usually used in theliterature of inequality, allowing some different analyzes and that can help in thestudy of income inequality.

Le plasma de quarks et de gluons (QGP) est un état de la matière nucléaire apparaissant à hautedensité d’énergie. En laboratoire, il est possible de reproduire de telles conditions grâce aux collisionsd’ions lourds aux énergies ultra-relativistes. ALICE (A Large Ion Collider Experiment) estl’expérience du LHC dédiée à la mise en évidence du QGP.Différentes signatures ont été proposées et étudiées expérimentalement comme manifestations duQGP. Parmi celles-ci, le méson J/ψ joue un rôle central. Il fait partie de la famille des quarkonia,états mésoniques (Q¯Q) formées d’un quark lourd c ou b et de son anti-quark, liés par un potentield’interaction forte. En 1986, Matsui et Satz proposèrent la suppression des charmonia (états liés cc)et notamment du J/ψ comme signature de la formation du plasma de quarks et de gluons.ALICE peut détecter le J/ψ à grande rapidité (2.5 < y < 4) via le canal de désintégration en deuxmuons. Cette thèse porte sur la mesure de la production du J/ψ, via le canal muonique, dans lescollisions pp à une énergie dans le centre de masse de 2.76 et 7 TeV. Elle a exploité les donnéesacquises en 2010 et 2011 auprès du collisionneur LHC.Tenter d’appréhender le mécanisme de production du J/ψ (et plus généralement du quarkonium)dans les collisions pp est un préalable nécessaire avant d’aborder le degré de complexité suivantque constitue le cas des collisions noyau-noyau. Il est également un test important pour la QuantumChromo Dynamics (QCD), la théorie de l’interaction forte, aux énergies très élevées du LHC. / Quarkonia are meson states whose constituents are a charm or bottom quark and its correspondingantiquark (Q¯Q). The study of the production of such bound states in high-energy hadron collisionsrepresents an important test for the Quantum Chromo-Dynamics. Despite the fact that the quarkoniumsaga has already a 40-year history, the quarkonium production mechanism is still an open issue.Therefore, measurements at the new CERN Large Hadron Collider (LHC) energy regimes are extremelyinteresting.In this thesis, the study of inclusive J/ψ production in proton-proton (pp) collisions at √s = 2.76and 7 TeV, obtained with the ALICE experiment, is presented. J/ψ mesons are measured at forwardrapidity (2.5 < y < 4), down to zero pT, via their decay into muon pairs (μ+μ−).Quarkonium resonances also play an important role in probing the properties of the stronglyinteracting hadronic matter created, at high energy densities, in heavy-ion collisions. Under suchextreme conditions, the created system, according to QCD, undergoes a phase transition from ordinaryhadronic matter to a new state of deconfined quarks and gluons, called Quark Gluon Plasma(QGP). The ALICE experiment at CERN LHC has been specifically designed to study this state ofmatter. Quarkonia, among other probes, represents one of the most promising tools to prove the QGPformation. In order to correctly interpret the measurements of quarkonium production in heavy-ioncollisions, a solid baseline is provided by the analogous results obtained in pp collisions.Hence, the work discussed in this thesis, concerning the inclusive J/ψ production in pp collisions,also provides the necessary reference for the corresponding measurements performed in Pb-Pb collisionswhich were collected, by the ALICE experiment, at the very same center-of-mass energy pernucleon pair (√sNN = 2.76 TeV).

Cette thèse vise à utiliser le t-J Hamiltonian de la corrélation forte pour mieux comprendre la micro-fonctionnalité des scénarios de matériau condensé. Un des problèmes qui existe depuis longtemps est que pour ce type de modèle comme Hubbard Hamiltonian ou t-J Hamiltonian avec une corrélation forte ne peut pas être résolu complètement analytiquement. Par conséquent, quand on aborde ces modèles, il est important de les exploiter de façon numérique. Dans cette thése, nous utiliserons la manière qui s'appelle "Renormalized Mean-Field Theory"(RMFT) pour le t-J Hamiltonian. Grâce à M. Gutzwiller, ce que nous devons faire est simplement de chiffrer des paramètres qui incluent l'influence de la corrélation électronique et de les mettre avant chaque partie du Hamiltonian. Après ce calcul, nous calculerons l'Hamiltonian du champ moyen de manière standard. Ceci sera notre façon principale pour aborder des questions physiques. Ensuite, nous l'appliquerons sur deux systèmes. Le premier est la mystique de supraconducteur à haute température. Après sa découverte il y a 30 ans, on ne peut pas encore définir une théorie pour expliquer sa micromécanique de manière appropriée. Cependant, avec des équipements avancés, on peut faire des expériences correctement et obtenir des résultats exacts. Ces preuves nous facilitent l'élaboration d'une bonne théorie, même s'il est aussi très difficile d'inclure tous les phénomènes ensemble. Nous avons obtenu des résultats et par rapport aux expériences, ils sont similaires qualitativement. Nous montrerons les détails dans le texte. Le deuxième système qui nous intéresse est le mouvement d'électron dans un champ magnétique fort. Le papillon d'Hofstadter et son modèle, l'Hamiltonian de Harper-Hofstadter ont obtenu un grand succès à décrire la mécanique d'électrons libres aux treillis. Donc il est ainsi intéressant de se demander ce qu'il se passera si nous remplaçons des électrons libres avec ceux qui s'interagissent. D'ailleurs, t-J Hamiltonian s'utilise comme bon modèle à le découvrir. Nous allons comparer nos résultats avec ceux de la diagonalisation exacte. Nous proposerons des découvertes intéressantes qui désormais seront réalisées par l'expérience d'atome froide. / This thesis is aiming in utilizing the strongly correlated t-J Hamiltonian for better understanding the microscopic pictures of certain condensed matter scenario. One of the long existing issues in the Hubbard model and its extreme version, t-J model, lies in the fact that there is not an analytical way of solving them. Therefore, when dealing with these models, numerical approaches become very crucial. In this thesis, we will present one of the methods called renormalized mean-field theory (RMFT) and exploit it upon the t-J model. Thanks to the concept proposed by Gutzwiller, all we have to do is to try to include the correlation of electrons, which is mainly the most difficult part, with several renormalization factors. After obtaining the correct form of these factors, we can apply the routine mean-field theory in solving for the Hamiltonian, which is the principle methodology throughout this thesis. Next, the physical systems that we are interested in consist of two parts. The mystery of High-Tc superconductivity comes first. After 30 years of its discovery, people still cannot settle down a complete microscopic theory in describing this exotic phenomenon. However, with more and more experimental equipment with higher accuracy nowadays, lots of behavior of copperoxide superconductor (also known as cuprate) have been revealed. Those discoveries can definitely help us better understand its microscopic mechanism. Therefore, from the theoretical side, to compare the calculated data with experiments leads us to know whether our theory is on the right track or not. We have produced tons of data and made a decent comparison which will be shown in the main text. The second system we are curious about is the mechanism of electrons under magnetic field. The Hofstadter butterfly along with its Hamiltonian, the Harper-Hofstadter model has achieved great success in describing free electrons' movement with lattice present. Thus, it will be also interesting to ask the question: what will happen if the electrons are correlated. Our RMFT for t-J Hamiltonian, by adding an additional phase in the hopping term, happens to serve as a great preliminary model for answering this question. We will compare the results of ours with our collaborators, who solved this model by a different approach, the exact diagonalization(ED). Together with our calculations, we proposed several discoveries which might be realized by the cold atom experiments in the future.

Version commerciale remaniée de: Dissertation--Philosophische Fakultät--Münster im Westfalen--Westfälische Wilhelms-Universität, 2005. / Bibliogr. p. 401-427.

Thesis (Ph. D.)--University of California, San Diego, 2001. / Vita. Includes bibliographical references (leaves 673-700).