Le développement d'un vaccin anti-paludique est limité par notre connaissance incomplète des effecteurs agissant contre P.falciparum. Nous avons mis en évidence que les cellules T Vγ9Vδ2 sont activées par la forme intra-érythrocytaire (schizonte) et par les phosphoantigènes de P.falciparum, et peuvent inhiber la croissance du parasite in vitro par un mécanisme dépendant de la granulysine ciblant la forme invasive du parasite (mérozoïte). Ces résultats suggérent que les lymphocytes T Vγ9Vδ2 jouent un rôle dans le contrôle précoce de la charge parasitaire. Cependant, le mécanisme médiant l’interaction entre les schizontes, les mérozoïtes les cellules T Vγ9Vδ2 et reste élusif. L'objectif de cette thèse est d’étudier les interactions entre les stades sanguins de P. falciparum et les cellules T Vγ9Vδ2, afin de mieux comprendre leurs activités anti-parasitaires, dans le but à long terme d’une utilisation clinique. Dans ce travail, nous étudions l'importance du contact direct avec les parasites dans l’activation et les activités anti-parasitaires des cellules T Vγ9Vδ2, par des approches de microscopie confocale et de cytométrie en flux. Nous suggérons que les cellules T Vγ9Vδ2 forment peu ou pas de contacts avec les mérozoïtes, et très peu de contacts avec le schizonte. De plus, nous montrons que, contrairement à une lignée cellulaire tumorale cible (Daudi), le contact avec les schizontes n'affecte pas l'activation des cellules T Vγ9Vδ2, suggérant que les phosphoantigenes du parasite sont libérés dans le milieu. Nous démontrons que les phosphoantigènes produits par la voie DOXP sont probablement libérés par un processus actif, dépendant des new permeation pathways (NPP). Ensembles, ces résultats suggèrent que l'activation et l'activité antiparasitaire des cellules T Vγ9Vδ2 n’est pas dépendante du contact, mais est médié par des facteurs solubles. / The limited knowledge of immune effector against Plasmodium falciparum precludes the development of a malaria efficient vaccine. We have recently evidenced that Vγ9Vδ2 T cells act as a new immune effector early in malaria infection. These cells are activated by the mature intraerythrocytic form (schizont) and by parasite-derived antigens (phosphoantigens). After activation, they inhibit in vitro parasite growth by targeting the extraerythrocytic invasive form (merozoite), by a granulysin-dependent mechanism. However, the mechanism by which Vγ9Vδ2 T cells are activated by schizonts and target merozoites remains elusive. The aim of this PhD project is to describe the interactions between P.falciparum blood stages and γδ T cells, in order to better understand their anti-parasitic activities and in the long term goal to manipulate these cells to prevent malaria. In the work, we investigate the importance of cell to parasite contact in Vγ9Vδ2 T cell activation and anti-parasitic activity by time-lapse and fixed confocal imaging, and cytometry. We suggest that Vγ9Vδ2 T cells form little or no contacts with merozoites, and very few contacts with the mature intraerythrocytic (schizont) form of the parasite. Moreover, we show that cytotoxic activities are elicited by schizonts, but that contrary to a known tumor cell line (Daudi cells), contact has no effect on the level of activation, suggesting that parasite-derived phosphoantigens are secreted in the microenvironment. We pursue the characterization of the parasite-derived phosphoantigens and demonstrate that they are produced by the DOXP pathway. Lastly, we show that phosphoantigens are most likely released by an active process, dependent on the new permeation pathways. Altogether, these results shed light on an unconventional mode of activation by P.falciparum blood stages and antiparasitic activity of Vγ9Vδ2 T cells, which is not contact-dependent, but rather is mediated by soluble factors.

Este trabalho descreve o projeto de um modulador Analógico-Digital (A/D) Sigma-Delta de 16 bits (98 dB de SNR) de baixo consumo em tecnologia CMOS para a aquisição de sinais de áudio. Para projetar o modulador foi utilizada a metodologia top down, a qual consiste em projetar desde o nível de sistema até os blocos básicos em nível de transistores. O sistema foi analizado e projetado utilizando equacões e modelos comportamentais para obter as especificações de cada bloco do modulador. Considerando um baixo consumo de potência foi escolhida a topologia CIFF (do inglês Chain of Integrator with FeedForward) de terceira ordem e quatro bits implementado com capacitores chaveados. O modulador projetado é composto por três integradores chaveados, um somador analógico, um weigthed DAC e um quantizador de quatro bits. A técnica de Chopper é incluida no modulador para diminuir o ruído Flicker na entrada do modulador. Os blocos de maior consumo dentro do modulador são as OTAs. Por esta razão eles são projetados utilizando a metodologia gm/ID reduzindo assim o consumo de potência. O projeto foi realizado na tecnologia IBM 0,18 \'mü\'m sendo utilizado o simulador spectre do Cadence. O modulador Sigma-Delta atinge um SNR de 98 dB para uma banda de 20 kHz e um consumo de potência de 2,4 mW para uma fonte de alimentação de 1,8 V. / This work describes the design of a 16 bits low power Sigma-Delta modulator (98 dB SNR) in a CMOS technology for the acquisition of audio signals. To design the modulator it was used the top-down methodology, which consists on the design from system level to the transistor-level basic blocks. The system was analyzed and designed using behavioral models and equations to obtain the specifications of each block of the modulator. Considering a low power consumption it was chosen a third-order four bits CIFF topology (Chain Integrator with feedforward) implemented with switched capacitors. The modulator is composed by three integrators, one analog adder, one weigthed DAC and one four bit quantizer. The Chopper technique is included in the modulator to reduce the Flicker noise at the input of the modulator. The blocks of higher consumption within the modulator are the OTAs. Hence, they was designed using the methodology gm/ID to reduce power consumption. It was designed on the 0.18 \'mü\'m IBM technology and using the Cadence Spectre simulator. The Sigma-Delta modulator achieves a SNR of 98 dB for a bandwidth of 20 kHz and a power consumption of 2.4 mW with a 1.8 V power supply.

Man Chi-shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 198-205). / Abstracts in English and Chinese. / List of Tables --- p.i. / Abstract --- p.ii. / 摘要 --- p.iii. / Acknowledgement --- p.iv. / Chapter Chapter 1 --- Going into migrants in the Pearl River Delta --- p.1 / Chapter I --- The living strategy besides political resistance --- p.2 / Chapter II --- Exploring the migrants in township-and-village areas of the Pearl River Delta --- p.6 / Chapter III --- Methodology --- p.9 / Chapter IV --- Overview of this study --- p.13 / Chapter V --- Terms clarification --- p.14 / Chapter Chapter 2 --- Literature review: understanding migrants in South China --- p.16 / Chapter I --- Migration --- p.18 / Chapter II --- Floating population in China after the economic reforms --- p.22 / Chapter III --- Theoretical framework --- p.38 / Chapter Chapter 3 --- A dichotomous community: the construction of oppressed and oppressor in Tianshen Township --- p.59 / Chapter I --- Going down to the field site --- p.60 / Chapter II --- Unequal relationships between the oppressed and the oppressor --- p.73 / Chapter III --- Concluding remarks --- p.97 / Chapter Chapter 4 --- "The voice from migrants: ""The outside world is splendid, but also ruthless.""" --- p.102 / Chapter I --- Living experience --- p.103 / Chapter II --- Working experience --- p.110 / Chapter III --- Floating: a short stage of life --- p.117 / Chapter IV --- Concluding remarks --- p.131 / Chapter Chapter 5 --- Exit and familism: the ways to accommodate dissatisfaction --- p.135 / Chapter I --- The infrequency of direct confrontation --- p.136 / Chapter II --- Job switching as a from of self-defense --- p.140 / Chapter III --- The significance of family support --- p.148 / Chapter IV --- A case study: the entanglement between survival and exploitation --- p.157 / Chapter V --- Concluding remarks --- p.163 / Chapter Chapter 6 --- Economic retreatism: the basic reason of the social stability in the Pearl River Delta --- p.168 / Chapter I --- A comparison with Scott's and Popkin's cases --- p.169 / Chapter II --- A supplement to previous studies concerning Chinese migrant workers --- p.180 / Chapter III --- Suggestions --- p.182 / Chapter IV --- Prediction --- p.184 / Chapter V --- IEpilogue --- p.185 / Appendix A: List of Interviewees --- p.189 / Appendix B: Photos --- p.190 / Appendix C : Cartoon --- p.195 / Appendix D: Map --- p.197 / Bibliography --- p.198

Soil organic matter (SOM) plays an important role in the global carbon cycle. Therefore, it is important to understand the stability of SOM, which is related to several processes. Its intrinsic properties may be related to its stability, for example black carbon is considered to be relatively resistant to degradation. In most soils, the dark horizons coincide with the superficial layers or horizons due to the greater accumulation of organic matter, but in the southern states of Brazil, the presence of soils with dark subsurface horizons is frequently observed. The dark subsurface horizon of these soils are similar to a sombric horizon. Aspects about its origin, formation and preservation have not yet been fully elucidated. The objective of this work is to understand the formation of \'sombric\' horizons in soils of the region from Tijucas do Sul (Paraná, Brazil). Five soil profiles were described and collected, from which three originate from a toposequence and contained a \'sombric\' horizon (P1-P3), a reference soil that is representative of the area (P5) and an intermediate soil (P4) that showed morphology between the reference soil and the soils with a \'sombric\' horizon. To this end SOM is studied for its molecular composition by the pyrolysis technique coupled to gas chromatography and mass spectrometry (pyrolysis-GC-MS). In addition, 13C isotopic composition (δ13C) and phytolytic composition were studied in order to understand paleoclimatic conditions. These results will be related to past environmental conditions using 14C dating techniques, and supported by classical soil analysis. The samples of the horizons were submitted to the SOM chemical fractionation, generating two fractions: extractable fraction with NaOH (EXT) and residue (RES). The morphology of the profiles showed an intense biological activity in A horizons and a wide distribution of microfragments of charcoals. The lateral continuity of \'sombric\' horizons in toposequence soils was also observed, which differentiated them (P1-P3) from buried A horizons. The distribution of SOM in the fractions studied was the same for the five profiles studied: EXT> RES. Products related to wildfires such as polyaromatics (PAHs; BC) were found in all profiles, but in greater relative abundance in the \'sombric\' horizons, indicating a higher incidence of fire during the formation of these horizons and these compounds can be related to the maintenance of dark color of the \'sombric\' horizons. In relation to the paleoclimatic conditions it was observed that the dark subsurface horizons were developed during the Mid-Holocene under vegetation composed mainly by C4 grasses with shrubs, evidencing a drier climate corresponding to a higher fire incidence. / A matéria orgânica do solo (MOS) desempenha um papel importante no ciclo global do carbono. Portanto, é importante entender a estabilidade da MOS, que está relacionada a vários processos. As suas propriedades intrínsecas podem estar relacionadas com a sua estabilidade, por exemplo, o \"black carbon\" é considerado relativamente resistente à degradação. Na maioria dos solos, os horizontes escuros coincidem com as camadas ou horizontes superficiais devido ao maior acúmulo de matéria orgânica, mas nos estados do sul do Brasil, a presença de solos com horizontes subsuperficiais escurecidos é frequentemente observada. O horizonte subsuperficial escurecido destes solos assemelha-se a um horizonte sômbrico. Aspectos sobre sua origem, formação e preservação ainda não foram totalmente elucidados. O objetivo deste trabalho é compreender a formação de horizontes \'sômbricos\' em solos da região de Tijucas do Sul (Paraná, Brasil). Foram descritos e coletados cinco perfis de solo, dos quais três estão localizados em uma topossequência e continham um horizonte similar ao sômbrico (P1-P3), um solo de referência representativo da área (P5) e um solo intermediário (P4) que apresentou uma morfologia entre o solo de referência e os solos com horizonte \'sômbrico\'. Para este fim, a MOS foi estudada pela sua composição molecular através da técnica de pirólise acoplada à cromatografia gasosa e espectrometria de massa (pirólise-GC-MS). Além disso, estudou-se a composição isotópica 13C (δ 13C) e a composição fitolítica, a fim de compreender as condições paleoclimáticas que foram relacionados com as condições ambientais passadas usando técnicas de datação com 14C, e suportados pelas análises clássicas de solo. As amostras dos horizontes foram submetidas ao fracionamento químico MOS, gerando duas frações: fração extraível com NaOH (EXT) e resíduo (RES). A morfologia dos perfis mostrou uma intensa atividade biológica nos horizontes A e uma ampla distribuição de microfragmentos de carvão. Observouse também a continuidade lateral de horizontes \'sômbricos\' em solos da topossequência (P1-P3), diferenciando-os dos horizontes A enterrados. A distribuição da MOS nas frações estudadas pela pirólise foi a mesma para os cinco perfis: EXT> RES. Os produtos relacionados a incêndios florestais como os poliaromáticos (PAHs, BC) foram encontrados em todos os perfis, mas em maior abundância relativa nos horizontes sômbricos, indicando uma maior incidência de incêndio durante a formação destes horizontes. Os PAHs podem estar relacionados com a manutenção da cor escura dos horizontes \'sômbricos\'. Em relação às condições paleoclimáticas observou-se que os horizontes subsuperficiais escurecidos foram desenvolvidos durante o Holoceno Médio sob vegetação composta principalmente por gramíneas C4 com arbustos, evidenciando um clima mais seco correspondente a maior incidência de incêndio.

abstract: This dissertation proposes and presents two different passive sigma-delta modulator zoom Analog to Digital Converter (ADC) architectures. The first ADC is fullydifferential, synthesizable zoom-ADC architecture with a passive loop filter for lowfrequency Built in Self-Test (BIST) applications. The detailed ADC architecture and a step by step process designing the zoom-ADC along with a synthesis tool that can target various design specifications are presented. The design flow does not rely on extensive knowledge of an experienced ADC designer. Two example set of BIST ADCs have been synthesized with different performance requirements in 65nm CMOS process. The first ADC achieves 90.4dB Signal to Noise Ratio (SNR) in 512µs measurement time and consumes 17µW power. Another example achieves 78.2dB SNR in 31.25µs measurement time and consumes 63µW power. The second ADC architecture is a multi-mode, dynamically zooming passive sigma-delta modulator. The architecture is based on a 5b interpolating flash ADC as the zooming unit, and a passive discrete time sigma delta modulator as the fine conversion unit. The proposed ADC provides an Oversampling Ratio (OSR)- independent, dynamic zooming technique, employing an interpolating zooming front-end. The modulator covers between 0.1 MHz and 10 MHz signal bandwidth which makes it suitable for cellular applications including 4G radio systems. By reconfiguring the OSR, bias current, and component parameters, optimal power consumption can be achieved for every mode. The ADC is implemented in 0.13 µm CMOS technology and it achieves an SNDR of 82.2/77.1/74.2/68 dB for 0.1/1.92/5/10MHz bandwidth with 1.3/5.7/9.6/11.9mW power consumption from a 1.2 V supply. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2018

Xu, Fang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 75-79). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background Information --- p.3 / Chapter 2.1 --- Growth of Air-Transportation Industry --- p.3 / Chapter 2.1.1 --- General Figures --- p.3 / Chapter 2.1.2 --- Growth of Air Cargo Market --- p.3 / Chapter 2.1.3 --- Regulatory Support --- p.5 / Chapter 2.2 --- The Focus: Pearl River Delta --- p.6 / Chapter 2.2.1 --- Strategic Moves of Airports --- p.8 / Chapter 2.2.2 --- Investment and Development of Airlines --- p.12 / Chapter 2.2.3 --- Hong Kong VS Shen Zhen --- p.13 / Chapter 3 --- Airport Competition --- p.14 / Chapter 3.1 --- Introduction --- p.14 / Chapter 3.2 --- One-period two port competition model --- p.15 / Chapter 3.2.1 --- The basic model --- p.15 / Chapter 3.2.2 --- Stackelberg Game --- p.23 / Chapter 3.2.3 --- Location factor --- p.26 / Chapter 3.3 --- Two-period two port competition model --- p.27 / Chapter 3.3.1 --- The basic model --- p.27 / Chapter 3.3.2 --- Switching cost --- p.30 / Chapter 3.4 --- Conclusion --- p.33 / Chapter 4 --- Combined airline VS full-cargo airline --- p.34 / Chapter 4.1 --- Introduction --- p.34 / Chapter 4.2 --- Model Setup --- p.35 / Chapter 4.2.1 --- Modelling Capacity and Cost --- p.35 / Chapter 4.2.2 --- Modelling Demand --- p.37 / Chapter 4.2.3 --- The Optimization Framework --- p.37 / Chapter 4.2.4 --- Decomposition of the Decision Process --- p.39 / Chapter 4.3 --- Step 1: Strategies in the Passenger Market --- p.40 / Chapter 4.3.1 --- Carriers enter the game with zero-inventory --- p.40 / Chapter 4.3.2 --- Incumbent carrier has established initial capacity --- p.42 / Chapter 4.4 --- Step 2: Strategies in the Cargo Market --- p.45 / Chapter 4.5 --- Centralized decision --- p.49 / Chapter 4.5.1 --- Both airlines have zero initial capacity in the passenger market --- p.50 / Chapter 4.5.2 --- One airline has non-zero initial capacity in the passenger market --- p.51 / Chapter 4.5.3 --- Both airlines have initial capacity in the cargo market --- p.53 / Chapter 4.6 --- Conclusion --- p.53 / Chapter 5 --- Demand growth and shifting --- p.55 / Chapter 5.1 --- Introduction --- p.55 / Chapter 5.2 --- Competition Scenario --- p.56 / Chapter 5.2.1 --- Growth and shifting of passenger demand --- p.56 / Chapter 5.2.2 --- Growth and shifting of cargo demand --- p.60 / Chapter 5.3 --- Centralized decision making --- p.64 / Chapter 5.4 --- conclusion --- p.72 / Chapter 6 --- Conclusion --- p.73 / Bibliography --- p.75

Os vírus da hepatite B (HBV), C (HCV) e Delta (HDV) causam grande impacto para a saúde pública mundial. Noventa e duas, oito e quatro amostras para HBsAg, anti-HD e anti-HCV, respectivamente, foram identificadas em indivíduos no Maranhão. Cinquenta amostras positivas para HBV DNA foram classificadas em subgenótipo D4 (42/86%) e A1 (8/14%). Para o HDV, apenas quatro foram classificadas como HDV-8. As amostras positivas para anti-HCV não apresentaram RNA detectável. O HBV-D4 parece ser o principal vírus representante na região estudada. O estudo filogenético sugere que houve a introdução de uma única cepa do subgenótipo D4 no Maranhão, enquanto que para o subgenótipo A1 existiu introdução de diferentes cepas. A confirmação do achado do HDV-8 em coinfecção com HBV- D4 suporta a hipótese de origem desses vírus na África. A ausência de infecção ativa pelo HCV é provavelmente devido uma introdução recente desse vírus e/ou menor frequência de meios de transmissão eficientes. Mais estudos são necessários em regiões onde é desconhecido o perfil de infecção desses vírus. / Hepatitis B (HBV), C (HCV) and Delta (HDV) viruses cause a great universal public health concern. Ninety-two, eight and four positive individuals for HBsAg, anti-HD and anti-HCV were identified, respectively. Fifty samples for HBV were classified in. subgenotype D4 (42/86%) and A1 (8/14%). Concerning HDV, four samples were identified as HDV-8 genotype. Anti-HCV positive samples were negative for RNA. HBV-D4 seems to be the main representative in the studied region. The phylogenetic tree topology suggests there was the introduction of a single strain of D4 subgenotype in Maranhao, whereas subgenotype A1 had several introductions of different strains. The finding of HDV-8 in coinfection with HBV D4 confirms the hypothesis of origin of these viruses in Africa. The low number of HCV infection in this region may be due to the recent introduction of this virus and / or lower frequency of efficient means of transmission. More studies are necessary in other regions where the infection profile of these viruses is indefinite.

Les récepteurs opioïde delta (DORs) sont des récepteurs couplés aux protéines G et sont fortement exprimés au niveau du bulbe olfactif, du cortex, du striatum, du noyau basolateral de l'amygdala et des noyaux du pons (Mansour et al., 1995; Le Merrer et al., 2009). Les souris mutantes de première génération (souris knockout, délétion totale du gène) ont déjà permis de démontrer que DOR joue un rôle critique dans le contrôle de la douleur chronique (Gavériaux-Ruff et al., 2011), la régulation de l’activité motrice et des réponses émotionnelles (Filliol et al ., 2000) et l’association drogue-contexte (Le Merrer et al., 2011). Le but de notre étude est d’identifier les circuits neuronaux dans lesquels les DORs contrôlent les processus émotionnels et cognitifs. Nous avons développé une lignée de souris de deuxième génération, dans laquelle les récepteurs sont supprimés spécifiquement dans les neurones GABAergiques du cerveau antérieur. Nous avons ensuite étudié le rôle des DORs exprimés par ces neurones dans les réponses émotionnelles, locomotrices et la sensibilité aux crises épileptiques. / Delta opioid receptors (DORs) are G-protein coupled receptors belonging to the opioid system, which play a central role in chronic pain and emotional responses. DORs are strongly expressed in olfactory bulb, cortex, striatum, basolateral nucleus of the amygdala and pons nuclei. Using constitutive gene knockout, we have previously demonstrated the role of DORs in reducingchronic pain (Gaveriaux-Ruff, Nozaki et al. 2011), anxiety-related behaviors and impulsivity(Olmstead,Ouagazzal et al. 2009), regulating locomotor activity (Filliol, Ghozland et al. 2000) and facilitating context learning (Le Merrer, Faget et al. 2012; Le Merrer, Rezai et al. 2013), Although these functions are well-established, neuronal networks and mechanisms underlying DOR-regulated behaviors remain poorly understood. The aim of this thesis work was to identify neuronal populations and brain circuits that support DOR functions. Recent evidence showed that DOR is highly expressed in GABAergic neurons (Scherrer et al.. 2006;Erbs et al., 2012; Rezai et al.. 2012). We therefore developed a conditional knockout mouse line (Dlx-DOR)by breeding floxed DOR gene (Oprd1) with a transgenic Dlx-5/6-Cre mouse line (Monorv et al., 2006) in order to produce a specific deletion of DOR in GABAergic neurons of the forebrain. We first determined brain distribution of delta receptors in Dlx-DOR at mRNA and protein levels. Then, behavioral analysis were performed to assess whether DORs expressed in forebrain GABAergic neurons contribute to the regulation of emotional contrai, locomotor activity as well as epileptogenic effect of SNC80, the prototypal DOR agonist. Finally, we initiated a project focused on DORs detected at the level of BLA.

Les travaux présentés ici visent à déterminer l’implication du récepteur aux opioïdes delta dans des modèles de pathologies chroniques telles que la douleur chronique et l’administration d’opiacés. Nous avons mis en oeuvre des approches génétiques, d’imagerie et comportementales afin de décrire précisément les changements de distribution neuronale du récepteur aux opioïdes delta dans un modèle de douleur neuropathique et dans l’administration chronique de morphine, dans les tissus du système nerveux central et périphérique. Nous avons étudié l’implication des récepteurs aux opioïdes delta périphériques dans l’effet thérapeutique de traitements antiallodyniques dans un modèle de douleur neuropathique, et examiné le rôle des récepteurs aux opioïdes delta dans la sensibilité viscérale et dans les effets thérapeutiques de la Prégabaline. Nos travaux ont permis de décrire précisément les changements et l’implication du récepteur aux opioïdes delta dans plusieurs modèles de pathologies chroniques, dans le but de dégager des pistes thérapeutiques futures. / In this work, we used genetic, imaging and behavioral approaches to describe the changes which the distribution of the delta opioid receptor underwent in models of clinical conditions such as neuropathic pain and chronic opioid exposure, at the peripheral and supraspinal levels. We investigated the role of peripheral delta opioid receptor populations in the antiallodynic effect of chronic treatment by antidepressant and β2 agonist molecules in a model of neuropathic pain. We also described the implication of delta opioid receptors in visceral sensitivity, and their involvement in the pain-relieving effects of Pregabalin in a model of neuropathic pain. Thus, we have brought insight as to the role of delta opioid receptors in these various clinical conditions, and thoroughly described the distribution changes; which may lead the way to therapeutic strategies to treat chronic pain or drug addiction.

Nesse trabalho, estudamos a equação de Schrödinger não-linear com uma função potencial delta atrativa. As soluções para essa equação tem uma componente localizada e uma dispersiva. Além de estudar o comportamento das soluções dessa equação em espaços de Sobolev clássicos, mostramos algumas propriedades do grupo unitário em espaços Lp, L2 com peso, Sobolev com peso e assim obtemos alguns resultados de boa colocação local e global das soluções. O ponto central desta tese é mostrarmos a existência de uma variedade invariante centro que irá consistir de órbitas periódicas no tempo. / In this work, we study the nonlinear Schrodinger equation with an attractive delta function potential.The solutions to this equation have a localized and a dispersive component. In addition to studying the behavior of solutions of this equation in classical Sobolev space, we show some properties for the unitary group in Lp, weighted L2 and Sobolev spaces and so we get some results of local and global well-posedness of solutions. The central theme this thesis is to show the existence of a center invariant manifold, which will consist of time-periodic orbits.