L’ostéoarthrose (OA) est une pathologie qui touche les articulations principalement chez les personnes âgées. Il devient capital de mieux cerner cette pathologie à cause des coûts économiques qu’elle engendre mais surtout à cause du vieillissement de la population. Cette maladie se caractérise par une dégradation du cartilage articulaire, une sclérose osseuse, une inflammation de la membrane synoviale ainsi que la présence d’ostéophytes. L’étiologie de cette pathologie est restée nébuleuse car la recherche sur la maladie touchait principalement le cartilage articulaire. Toutefois, le rôle clé de l’os sous-chondral dans l’OA est maintenant reconnu. L’obésité étant un facteur de risque de l’OA, nous avons émis l’hypothèse que la leptine, une adipocytokine clé dans l’obésité, joue un rôle important dans l’OA. En effet, la leptine modifie le phénotype des ostéoblastes (Ob) normaux humain et puisque les Ob OA humains ont un phénotype altéré, notre objectif était de déterminer le rôle potentiel de la leptine dans ces cellules. Pour ce faire, nous avons préparé des cultures primaires d’Ob issus de la plaque sous-chondral du plateau tibial de patients OA et d’individus normaux (N). L’expression de la leptine et de son récepteur actif (OB-Rb) ont été mesurées par RT-PCR en temps réel, et leur production a été mesurée par ELISA et immunobuvardage (IB). La prolifération des Ob OA a été déterminée par incorporation de BrdU. La phosphorylation de p42/44 MAPK dans les Ob OA a été déterminée par IB. Le phénotype des Ob fut déterminé par la mesure de l’activité de la phosphatase alcaline (ALP) et la sécrétion d’ostéocalcine (OC), en présence ou non de leptine. De plus, les effets des ARNs d’interférences (SiRNA) anti-leptine et anti OB-Rb sur le phénotype des Ob OA furent déterminés via leur impact sur l’activité de l’ALP et sur la sécrétion d’OC. L’effet dose-réponse de la leptine sur les expressions d’OB-Rb, du facteur de croissance TGF-1 ou encore sur sa propre expression furent déterminées par RT-PCR en temps réel. Pour terminer, la signalisation de la leptine a été étudiée en évaluant l’effet dose réponse de celle-ci sur la production des protéines JAK2 et STAT3 phosphorylées par IB. Les résultats obtenus ont montrés que les Ob OA expriment et produisent plus de leptine que les Ob N. Au niveau phénotypique, ces Ob OA possèdent une activité de l’ALP ainsi qu’une sécrétion d’OC plus importante que celles observées chez les Ob N. L’ajout d’anticorps inactivant l’interaction leptine et OB-Rb ou d’inhibiteurs chimiques comme tyrphostin ou piceatannol diminuèrent l’activité de l’ALP ainsi que la sécrétion d’OC dans les Ob OA. Par contre, l’ajout de leptine exogène aux Ob OA augmenta l’activité de l’ALP sans pour autant faire varier la sécrétion d’OC. La leptine à des doses de 1ng/ml à 10mg/ml stimula la prolifération des Ob OA ainsi que la phosphorylation de p42/44 MAPK. La leptine exogène diminua l’expression de TFG-1 tandis qu’elle stimula la phosphorylation de JAK2 et STAT3 ou encore sa propre expression de manière dose-dépendante. Cependant, l’expression d’OB-Rb diminua de manière dose-dépendante. Enfin, le traitement des Ob OA avec des Si leptine ou Si OB-Rb diminua l’activité d’ALP, la sécrétion d’OC, l’expression de la leptine, l’expression d’OB-RB ainsi que l’expression du facteur TGF-1. L’ensemble de ces données démontre que la leptine endogène des Ob OA est sous contrôle des facteurs de croissance et qu’elle contribue à maintenir le phénotype anormal de l’os sous-chondral OA. De plus, ceci suggère que la leptine serait un acteur important dans la régulation du remodelage osseux. / Osteoarthritis (OA) is a disease which mainly affects the joints in the elderly. It becomes essential to better understand this disease because of the economic costs it brings, but mainly because of population aging. This disease is characterized by a deterioration of cartilage, bone sclerosis, inflammation of the synovial membrane and the presence of osteophytes. The knowledge of its etiology has remained incomplete because research on this disease focused mainly on the articular cartilage. However, the key role of subchondral bone in OA is now recognized. Obesity is a risk factor for OA, then we hypothesized that leptin, a key adipocytokine in obesity plays an important role in OA. Indeed, leptin alters the phenotype of osteoblasts (Ob) and human Ob has altered phenotype in OA patients, our objective was to determine the potential role of leptin in OA Ob. To do this, we prepared primary cultures of Ob from the sub-chondral plate of the tibial plateaus of OA patients and normal individuals (N). The expression of leptin and its receptor active (OB-Rb) were measured by RT-PCR in real time, and their production was measured by ELISA and western blot (WB). The proliferation of Ob OA was determined by BrdU incorporation. The phosphorylation of p42/44 MAPK was evaluated by WB. The phenotype of Ob was determined by measuring the activity of alkaline phosphatase (ALP) and the secretion of osteocalcin (OC), in the presence or absence of leptin. Moreover, the effects of small interference RNAs (siRNAs) anti-leptin and anti OB-Rb on the phenotype of OA Ob were determined through their impact on the activity of the ALP and the secretion of OC. The dose-response effect of 1eptin on its own expression or the expressions of OB-Rb, the growth factor TGF-β1 were determined by RT-PCR in real time. Finally, signalisation of leptin in OA Ob was studied by evaluating the dose-response effect of this on the production of JAK2 and STAT3 protein phosphorylated by WB. The results showed that the OA Ob express and produce more leptin than N. Moreover, these Ob OA have an activity of the ALP and a secretion OC higher than those observed in N Ob. The addition of antibodies inactivating interaction leptin and OB-Rb or chemical inhibitors such as tyrphostin or piceatannol diminished the activity of the ALP and the secretion of OC in OA Ob against by the addition of exogenous leptin to Ob OA increased the activity of the ALP without influencing the secretion of OC. Leptin at doses of 1ng/ml to 10mg/mL stimulated the proliferation of OA Ob and the phosphorylation of p42/44 MAPK. Exogenous leptin decreased the expression of TGF-β1 while it stimulated the phosphorylation of JAK2 and STAT3 and expression of its own in dose-dependent manner. However, the expression of OB-Rb decreased in dose-dependent. Finally, the treatment of OA Ob with Si leptin or Si OB-Rb decreased activity of ALP, the secretion of OC, the leptin expression, expression of OB-Rb and the expression of TGF-β1 factor. All these data show that endogenous leptin Ob OA controls the growth factors and contributes to maintaining the abnormal phenotype of the subchondral bone OA. Moreover, this suggests that leptin is an important player in the regulation of bone remodelling

Dabartiniu laikotarpiu žmogiškųjų išteklių efektyvus vystymas įgyja vis didesnę svarbą. Tai siejasi su tuo, kad viešojo sektoriaus efektyvios veiklos užtikrinimui daugeliu atvejų reikalinga daugialypė specialistų kompetencija, kuriai pasiekti būtinos įvairios mokymo ir tobulinimo formos. Esminiais prioritetais tobulinant darbuotojų gebėjimus ir kompetenciją tampa darbuotojų mokymo problemų sprendimas, mokymo poreikių nustatymas bei sistemingo mokymo ir kvalifikacijos tobulinimo proceso sukūrimas, kas sąlygoja šio darbo aktualumą. Tačiau praktinis šių aspektų taikymas organizacijose stokoja mokslinio tyrinėjimo, todėl nuoseklaus darbuotojų mokymo(si) ir kvalifikacijos tobulinimo proceso ir jo ypatumų analizė Lietuvos mokslų akademijos Vrublevskių bibliotekoje sąlygoja šio darbo naujumą. Tyrimo tikslas – ištirti ir išanalizuoti darbuotojų mokymo(si) ir kvalifikacijos tobulinimo procesą Lietuvos mokslų akademijos Vrublevskių bibliotekoje. Minėtas procesas apibrėžia tiriamąjį objektą. Darbe analizuojama problema – ar organizacijoje darbuotojų mokymo(si) ir kvalifikacijos tobulinimo procesas vyksta nuosekliai, skatinant organizacijos bei darbuotojų vystymą, ir kokie dominuojantys šio proceso ypatumai. Tikslui pasiekti numatyti šie uždaviniai: 1) apžvelgti vyraujančias žmogiškųjų išteklių vystymo sampratas ir ypatumus, apibrėžti darbuotojų mokymo ir kvalifikacijos tobulinimo procesą, jo elementus ir funkcijas; 2) išnagrinėti esminius suaugusiųjų švietimą ir bibliotekininkų... [toliau žr. visą tekstą] / Nowadays efficient development of human resources becomes increasingly important. This is related to the fact that in many cases multiple competences of specialists, which require various training and improvement forms, are necessary in order to ensure effective activities of the public sector. Solutions of employees’ training related issues, determination of training needs and formation of a systematic training and qualification improvement process become the fundamental principles in improving skills and competences of the employees and this fact determines the relevance of this thesis. However, the practical application of these aspects within organizations requires scientific research, thus, the analysis of the consistent employee’s training and qualification improvement process as well as its peculiarities determines the novelty of this thesis. The goal of the research is to investigate and analyze the employees’ training and qualification improvement process in the Wroblewski Library of the Lithuanian Academy of Sciences. The abovementioned process defines the analyzed object. The problem analyzed in the thesis – whether the employees’ training and qualification improvement process is conducted in a consistent manner by promoting the development of the organization and its employees and what are the dominant peculiarities of this process. In order to achieve this goal the following tasks have been set: 1) to review the prevailing concepts and peculiarities of the... [to full text]

Un traumatisme de la moelle épinière (TME) est une condition dévastatrice entraînant la perte permanente de fonctions neuronales. L’objectif de cette thèse est de formuler de microsupports pharmacologiquement actif (MPAs) avec une surface de fibronectine (FN), libérant le« brain-derived neurotrophic factor » (BDNF) de façon controlée. Nous voulons combiner ce système avec des cellules souches mésenchymateuses (CSMs) pour la réparation de TME. Le BDNF nanoprécipité a été encapsulé dans les FN-MPAs et le profil de libération in vitro a été évaluée. Elle a montré une libération biphasique et prolongée de BDNF bioactifs. Nous avons combinés des cellules souches humaines mésenchymateuse issues de la moelle osseuse adulte (cellules MIAMI) et FN-MPAs avec un hydrogel non-toxique silanisés-hydroxypropylméthylcellulose (Si-HPMC). Nous avons démontré que les FN-MPAs et le Si-HPMC augmentait l'expression de marqueurs neuraux/neuronaux de cellules MIAMI après 1 semaine. En outre, l'environnement 3D (hydrogel ou FN-MPAs) a augmenté le sécrétome thérapeutique de cellules MIAMI. Pour avoir un système facile à appliquer en clinique, nous avons choisi d’utiliser les cellules souches de la papille apicale (SCAP) et FN-MPAs libérant ou non du BDNF pour la thérapie du TME. Plus de 90 % du SCAP complexée avec FN-MPAs (libérant ou pas BDNF) demeurent viables pendant 7 jours et il y a augmentation de l'expression des gènes neuronaux/oligodendrogliaux in vitro. La récupération de la fonction locomotrice a été significativement améliorée après la transplantation du SCAP complexée avec FN-MPAs-BDNF avec une coordination cohérente du membre postérieur après 28 jours de traitement. / Traumatic spinal cord injury (SCI) is a devastating condition resulting in permanent loss of neural functions. The objective of this thesis is to develop pharmacologically active microcarriers (PAMs) with a fibronectin (FN) surface that deliver biologically active brain derived neurotrophic factor (BDNF) in a controlled manner. We want to combine this system with adult mesenchymal stem cells (MSCs) for SCI repair. The nanoprecipitated BDNF was encapsulated in FN-PAMs and the in vitro release profile was evaluated. It showed a prolonged, bi-phasic, release of bioactive BDNF, without burst effect. We combined human marrow-isolated adult multilineage-inducible (MIAMI) stem cells and FN-PAMs with an injectable non-toxic silanized-hydroxypropylmethylcellulose (Si-HPMC) hydrogel. We demonstrated that FN-PAMs and the Si-HPMC hydrogel increased the expression of neural/neuronal differentiation markers of MIAMI cells after 1 week. Moreover, the 3D environment (FN-PAMs or hydrogel) enhanced the therapeutic MIAMI cell secretome. To have a clinically translatable system, we chose to use stem cells of the apical papilla (SCAP) and FNPAMs releasing or not BDNF for SCI therapy. More than 90% of SCAP complexed with FN-PAMs (releasing or not BDNF) remained viable for 7 days and an increased neuronal-oligodendroglial gene expression in vitro. The recovery of locomotor function was significantly improved after transplantation of SCAP complexed with FN-PAMs-BDNF with frequent to consistent forelimb-hindlimb coordination after 28 days of treatment.

Submitted by Anna Patricia Pachas Manrique (annapamanrique@gmail.com) on 2017-02-23T20:20:56Z No. of bitstreams: 1 20_02 (1).pdf: 1460371 bytes, checksum: e98c8f4713680550a770e8efcc7ffa14 (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2017-08-03T17:52:37Z (GMT) No. of bitstreams: 1 20_02 (1).pdf: 1460371 bytes, checksum: e98c8f4713680550a770e8efcc7ffa14 (MD5) / Made available in DSpace on 2017-08-18T14:34:31Z (GMT). No. of bitstreams: 1 20_02 (1).pdf: 1460371 bytes, checksum: e98c8f4713680550a770e8efcc7ffa14 (MD5) Previous issue date: 2016-08-29 / The speed and comprehensiveness global level with the pathogen has spread in recent years has drawn attention to the importance of the contact’s social network structure. In fact, the topology of the networks in which members of society interact has influenced the dynamics of epidemics. Studies have shown that pathogens when disiparem in scale-free networks have different effects when compared broadcast in random networks, such as the classic models. In these there were epidemic threshold, may somehow the health ministry have a control on the dissipation of diseases by applying certain measures such as vaccines. Already in models in which are considered the networks, specifically the free network scale, the threshold disappears. Thus, the epidemic threshold depends on the topology is required to include within this structure models Because of the importance of these networks, random networks and scalefree have been implemented along the epidemics of propagation models to check the epidemic threshold and the characteristic time, noting that the epidemic threshold disappears / A velocidade e a abrangência a nível mundial com que os agentes patogênicos tem se disseminado nos últimos anos tem chamado a atenção para a importância da estrutura da rede social de contato . De fato, a topologia das redes na qual os membros da sociedade interagem têm influenciado na dinâmica das epidemias.Estudos têm demostrado que os agentes patogênicos ao se dissiparem em redes livres de escala tem efeitos diferentes se comparado quando difundidos em redes aleatórias, como nos modelos clássicos. Nestes existiam limiar de epidemia ,podendo de alguma forma as entidades de saúde ter um controle sobre a dissipação das enfermidades , aplicando certas medidas como as vacinas por exemplo. Já nos modelos nos quais são consideradas as redes , especificamente a rede livre de escala,este limiar desaparece. Desta forma, o limiar de epidemia ao depender da topologia se faz necessário incluir esta estrutura dentro dos modelos epidemiológicos. Devido a importância destas redes , redes aleatórias e principalmente redes livres de escala foram implementadas junto a modelos de propagação de epidemias para verificar o limiar de epidemia e o tempo característico , verificando que o limiar de epidemia desaparece.

Les alliages aluminium-silicium (Al-Si) ont attiré une attention considérable en raison de leur importance pour les applications industrielles. Dans le présent travail, des alliages à haute pureté (Al-12.7 wt. % Si) avec et sans ajout de strontium (400 ppm), solidifiés lentement en creuset ou de façon dirigée (DS), ont été préparés et traités thermiquement. L'influence de l'ajout de strontium et des post-traitements thermiques sur les caractéristiques microstructuraux et cristallographiques des phases eutectiques a été étudiée de façon systématique. Les caractéristiques de croissance du silicium eutectique (Si) dans l'alliage non modifié ainsi que dans l'Al-12.7Si Sr-modifié ont été étudiés. Pour le cas du non-modifié, la formation répétée de variantes de macles mono-orientées permet une croissance rapide du silicium eutectique selon le mécanisme twin plane re-entrant (TPRE). Microscopiquement, les cristaux de silicium ont une forme de plaque allongée dans la direction <1 1 0> non conforme à la croissance selon <1 1 2> présumée par le modèle TPRE. L'élongation selon <1 1 0> est réalisée par des paires en zigzag <1 1 2> sur des plans de maclage parallèles, conduisant à une disparition alternative et à la création de macles rentrantes à 141°. Ce mécanisme de croissance permet aux cristaux de silicium de n'exposer que les plans {1 1 1} à faible consommation d'énergie à la consolidation. Pour les alliages modifiés au strontium, des changements importants de morphologie apparaissent dans le silicium eutectique, attribuable à la croissance de TPRE restreinte et au maclage induit par les impuretés (IIT). Ce dernier améliore la croissance latérale en formant de nouvelles macles avec des plans de macles parallèles, tandis que le second conduit à une croissance isotrope en formant des macles orientées différemment. Le traitement thermique provoque l'affinement des grains des deux phases eutectiques. L'affinement de l'α-Al se produit en même temps que la fragmentation et la sphéroïdisation du silicium et est principalement lié à la fracture des grains de silicium en raison de leur capacité limitée à accommoder la très grande dilatation thermique l'α-Al, ainsi qu'à la diffusion des atomes d'aluminium au cours du traitement thermique. La rupture du silicium génère une force de "capillarité" qui active la diffusion d'atomes d'aluminium dans la fissure. En raison du caractère de substitution de la diffusion de l'aluminium, la migration des lacunes vers l'intérieur de l'α-Al est induite lorsque l'aluminium se déplace dans les fissures, ainsi les vides de la fracture du silicium sont transférés à l'α-Al. De cette façon, les cristaux d'α-Al sont altérés et déformés. Les défauts cristallins produits, à leur tour, initient la restauration et même la recristallisation du α-Al, ce qui entraîne une diminution de taille de grain. La phase α-Al dans l'alliage de Al-12.7Si-0.04Sr solidifiée directionnellement, affiche une forte texture de fibre <1 0 0> parallèle à la direction de solidification. De très gros grains <1 0 0> α-Al sont principalement formés à la périphérie de l'échantillon cylindrique en raison des directions d'évacuation de chaleur favorables disponibles pour les trois directions [1 0 0]. Après traitement thermique, l'intensité de la texture de la phase α-Al diminue en raison de la restauration et de la recristallisation, mais le type de texture ne change pas. Pour la phase de silicium eutectique dans l'alliage de coulée, il y a deux fibres principales de texture, <1 0 0> et <1 1 0> parallèles à la direction de solidification, accompagnées de deux composantes faibles, <2 2 1> et <1 1 3> dans la même direction. Les fibres <1 0 0> et <1 1 0> correspondent à des grains de silicium situés sur la périphérie et dans le centre de l'échantillon. Les composantes <2 2 1> et <1 1 3> proviennent de plusieurs macles de grains orientés <1 1 0> et <1 0 0>. Les faibles intensités de ces deux composantes sont liées à leur fraction volumique mineure [...] / Al-Si alloys have attracted considerable attention due to their importance to industrial applications. In the present work, both crucible slowly solidified and slowly directionally solidified (DS) high-purity Al-12.7 wt. % Si alloys with and without 400 ppm Sr addition have been prepared and heat treated. The influence of Sr addition and post heat treatments on the microstructural and crystallographic features of the eutectic phases has been systematically studied. The growth characteristics of eutectic Si in the unmodified and the Sr-modified Al-12.7Si alloys were investigated. For the non-modification case, the formation of repeated single-orientation twin variants enables rapid growth of eutectic Si according to the twin plane re-entrant (TPRE) mechanism. Microscopically, Si crystals are plate-like elongated in one <1 1 0> direction that is not in accordance with the <1 1 2> growth assumed by the TPRE model. The <1 1 0> extension is realized by paired <1 1 2> zigzag growth on parallel twinning planes, leading to alternative disappearance and creation of 141° re-entrants. This growth manner ensures Si crystals to expose only their low-energy {1 1 1} planes to the melt. For the Sr-modification case, substantial changes appear in eutectic Si morphology, attributable to the restricted TPRE growth and the impurity induced twinning (IIT) growth. The first enhances lateral growth by forming new twins with parallel twinning planes, while the second leads to isotropic growth by forming differently oriented twins. Heat treatment brings about refinement of both eutectic phases. The refinement of the α-Al occurs concomitantly with the fragmentation and spheroidization of Si and is mainly related to the fracture of the Si crystals due to their limited capacity to accommodate the giant thermal expansion of the α-Al and the diffusion of Al atoms to the cracks during the heat treatment. The Si fracture generates “capillarity” force that activates the diffusion of Al atoms to the gap of the crack. Due to the substitutional feature of Al diffusion, the migration of vacancies toward the interior of the α-Al is induced when Al moves to the gaps, thus the voids of the Si fracture are transferred to the α-Al. In this way, the crystals of α-Al are distorted and defected. The produced crystal defects, in turn, initiate recovery and even recrystallization of the α-Al, resulting in grain refinement. The α-Al phase in the directionally solidified Al-12.7Si-0.04Sr alloy, displays a strong <1 0 0> fiber texture in the solidification direction. Giant <1 0 0> α-Al grains are mainly formed in the outer circle region of the cylindrical specimen due to the favorable heat evacuation directions available for the three <1 0 0> directions. After heat treatment, the texture intensity of the α-Al phase decreases due to the recovery and recrystallization, but the texture type does not change. For the eutectic Si phase in the as-cast alloy, there are two main fiber texture components, <1 0 0> and <1 1 0> in the DS direction, accompanied by two weak components, <2 2 1> and <1 1 3> in the same direction. The <1 0 0> and <1 1 0> components are from Si crystals located in the outer circle and center regions of the cylindrical specimen. The <2 2 1> and the <1 1 3> components are from multiple twins of the <1 1 0> and <1 0 0> oriented crystals. The weak intensities of these two components are related to their minor volume fraction. Once heat treated, the twinned parts with minor volume fractions enlarge at the expense of their twin related matrix, thus the <1 1 0> component is weakened and accompanied by the intensification of the components from the twins. The disappearance of the <1 1 3> component and the appearance of the <1 1 5> component are due to crystallographic rotation of Si crystals during their fragmentation

Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-13T13:01:16Z No. of bitstreams: 1 arquivototal.pdf: 7899614 bytes, checksum: f001983854e55609b8ccfb1ce80578f2 (MD5) / Made available in DSpace on 2017-09-13T13:01:16Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 7899614 bytes, checksum: f001983854e55609b8ccfb1ce80578f2 (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / One of the main problems that permeates the Particle Physics and Cosmology is the Dark Matter (DM), which makes up about 26% of the energy content of the Universe. The main evidence pointing to its existence provides us with important features, such as being neutral, stable (with lifetime over the age of the Universe), cold or warm, weakly interacting with Particle Physics Standard Model (SM) particles and sufficiently abundant. The SM does not provide a candidate who meets these characteristics and hence it is necessary to extend it. One of the most sophisticated extensions of the SM is the Supersymmetry, that in addition to solving the problem of DM, explains other unsolved puzzles that are present in SM, among them, the hierarchy and the unification of the gauge couplings. This model implies the inclusion of a new symmetry that puts bosons and fermions in equal footing. The minimal supersymmetric version of the SM is the Minimal Supersymmetric Standard Model (MSSM), whose viable candidate is the neutralino, which is a fermion composed of superpartners of neutral Higgs and gauge bosons. In this work, we performed the neutralino analysis as DM candidate in CMSSM or mSUGRA scenario, which contains 5 free parameters, M0, M1/2, tan , sign(μ) and A0, for two different analyzes. In the first one we varied the M0 and M1/2 parameters for three different values of tan while in the second and third one we varied all parameters except the sign(μ). In this study, we use some computational tools, including, SARAH, SPheno, SSP and Micromegas, in order to obtain DM Relic Abundance and DM scattering cross section in this scenario. We compared our results with the most recent experimental data, namely, we have used Planck satellite data for the relic abundance, LUX and XENON1T (prospect) for the spin-independent scattering cross section and XENON100 for the spin dependent one. We finally analyzed the implications concerning the viability of the MSSM under the light of the DM problem. / Um dos principais problemas que permeia a Física de Partículas e Cosmologia é a Matéria Escura (ME), que compõe cerca de 26% do conteúdo energético do Universo. As principais evidências que apontam para a sua existência nos fornecem importantes características, tais como, ser neutra, estável (com tempo de vida maior que a idade do Universo), fria ou morna, pouco interagente com partículas do Modelo Padrão de Física de Partículas (MP)e suficientemente abundante. O MP não fornece um candidato que supre estas características, sendo necessário estendê-lo. Uma das mais sofisticadas extensões do MP é a Supersimetria, que além de resolver o problema da ME, soluciona outros que estão presentes no MP, dentre eles, a hierarquia e a unificação dos acoplamentos de gauge. Tal modelo implica na inclusão de uma nova simetria que coloca bósons e férmions em pé de igualdade. A versão mínima supersimétrica do MP é o Modelo Padrão Supersimétrico Mínimo (MSSM), cujo candidato viável à ME é o neutralino, que se trata de um férmion composto pelos superparceiros dos bósons de gauge e Higgs neutros. Neste trabalho, fizemos uma análise do neutralino como candidato à ME no cenário CMSSM ou mSUGRA, que contém 5 parâmetros livres, M0, M1/2, tan , sinal(μ) e A0, para três análises distintas. Na primeira variamos apenas os parâmetros M0 e M1/2 para três valores distintos da tan e na segunda e terceira variamos todos os parâmetros com exceção do sinal(μ). Neste estudo, utilizamos algumas ferramentas computacionais, entre as quais, SARAH, SPheno, SSP e micrOMEGAs, no intuito de obter abundância e seção de choque de espalhamento de ME neste cenário. Obtidos os gráficos, comparamos com os resultados experimentais mais recentes, para a abundância utilizamos dados do satélite Planck, para a seção de choque de espalhamento independente de spin, o LUX e XENON1T (2017) e para dependente de spin, XENON100 e verificamos suas implicações na viabilidade do modelo.

The guidelines for this dissertation are to be found in two of Sartre s works, Being and Nothingness and Existentialism and Humanism. These two works form part of the composite body of texts written by Jean-Paul Sartre on ethics and authenticity. Other bibliographies have been drawn upon, with parts referred to at strategic points throughout this work. Ethics and authenticity in Sartre s philosophy form the basis for what I aim to examine, with three main areas of focus: uncovering what authenticity means to Sartre as a writer, how it can be an ethical concept and what its presence in human behaviour indicates. It would be meaningless to speak of authenticity if it were not for the notion of freedom always having Sartrean ontology at its core. To this end, the two initial chapters of this dissertation make an attempt to look more closely at the topic of ontology and to understand and recount the writer s main concerns with regard to authenticity and ethics. Following this, the major references comprise the commentators, all of whom have been duly cited in the final bibliography, and Sartre s literary works. And finally, ethics and authenticity would not have full meaning if it were not for the fact that they are grounded in existential ontology, because thinking of being, for Sartre, is thinking that one ought to be, which is being For-Itself, and reflecting on ethics means thematizing the original unity of its moral which lies in the authenticity of being and recognizing For-itself. / Dois livros de Sartre, O Ser e o Nada e O Existencialismo é um Humanismo, nos dão as diretivas dessa dissertação. As duas obras formam parte do complexo corpo de textos escritos por Jean-Paul Sartre para falar de ética e autenticidade. Outras bibliografias são levantadas, contudo, parte delas, mescladas em pontos estratégicos do trabalho. Ética e autenticidade na filosofia de Sartre é o que tentamos apresentar com três grandes preocupações; desvelar o que é a autenticidade para nosso autor, como ela pode ser um projeto ético e o que significa sua presença dentro do comportamento humano. Não teria sentido falar de autenticidade se não fosse por causa da liberdade tendo sempre em vista a ontologia sartriana. É por isso que os dois capítulos iniciais dessa dissertação tentam aprofundar o tema da ontologia para compreender e elencar as principais preocupações do autor em relação a autenticidade e a ética. A seguir as grandes referências são, os comentadores, que estão devidamente citados na bibliografia final, e as obras literárias de Sartre. E, finalmente, ética e autenticidade não encontrariam seu pleno sentido, se não fossem fundamentadas numa ontologia existencialista, porque pensar o ser, para Sartre, é pensar o dever-ser (que é Para-si) e refletir sobre ética, significa tematizar a unidade originária de sua moral que está na autenticidade de ser e se reconhecer Para-si. / Mestre em Filosofia

Nesta tese, utilizamos técnicas de química quântica para o estudo de sistemas contendo átomos de silício e nitrogênio. Nesse contexto, o trabalho aqui apresentado procurou concentrar-se em três tópicos principais: aglomerados de silício e nitrogênio, a superfície Si(100) e a interação de um átomo de nitrogênio com essa superfície. Estudamos inicialmente os aglomerados de fórmula SiNN e Si3N2, onde procuramos caracterizar de forma rigorosa a estabilidade e a natureza das ligações químicas das várias espécies. Com relação ao sistema SiNN, os resultados utilizando cálculos de alto nível mostraram a necessidade de novos dados experimentais para a caracterização inequívoca dessa espécie. Além disso, obtivemos os primeiros resultados para as propriedades de quatro novas estruturas. Estudamos a estrutura de várias espécies com fórmula Si3N2, e obtivemos como mínimo global uma estrutura planar contendo apenas ligações Si-N. Para a simulação da superfície Si(100) utilizamos os aglomerados de fórmula Si9H12 e Si15H16. Apenas a metodologia do Funcional da Densidade indicou a existência de uma estrutura distorcida para o Si9H12. Os cálculos CASSCF mostraram a necessidade do uso de funções multideterminantais. Com relação ao aglomerado Si15H16, obteve-se uma estrutura distorcida com os dímeros alternados como a forma mais estável. Entretanto, o uso do CASSCF mostrou ser a forma simétrica a mais estável. Com base no estudo dos aglomerados Si9H12 e Si15H16, partimos para a investigação dos mecanismos envolvidos no processo de interação e incorporação de átomos de nitrogênio na superfície de silício. Estruturas com simetria de spin quarteto e dupleto foram estudadas, sendo os mecanismos bastante semelhantes, com o nitrogênio interagindo inicialmente com um dos silícios dímeros para em seguida poder formar duas outras estruturas, uma com o nitrogênio ligado aos dois silícios dímeros e outra com o nitrogênio inserido no interior do aglomerado. Esta última estrutura corresponde à forma mais estável. Os resultados mostram claramente que a reação é bastante favorável do ponto de vista energético. Questionamos também o uso de vínculos durante a otimização das estruturas por impedir um devido relaxamento apropriado dos átomos de silício da primeira e segunda camadas. / In this thesis, quantum chemical techniques were used to study molecular systems containing silicon and nitrogen atoms. ln this context, the work was concentrated on three main topics: silicon-nitrogen clusters, the Si(100) surface, and the interaction of a nitrogen atom with that surface. We studied initially the clusters SiNN and Si3N2, where we tried to characterize with rigour the stability and the nature of the chemical bonds of the various species. Concerning the system SiNN, using high level calculation, the results showed the necessity of new experimental data for the unequivocal characterization of this species. Moreover, the properties of four new structures were described for the first time in this study. The structures of various species with formula Si3N2 were studied, and the global minimum corresponds to a planar structure containing only Si-N bonds. For the simulation of Si(100) surface, the clusters Si9H12 and Si15H16 were used. Density Functional Theory predicted the existence of an asymmetric geometry for the Si9H12 cluster. The CASSCF calculations showed the necessity of using multideterminantal wave functions. Concerning the Si15H16 cluster, the most stable structure corresponds to a distorted one with alternated dimers. However, the CASSCF methodology showed that the symmetric structure is the most stable. Based on the results for the Si9H12 and Si15H16 clusters, we started to investigate the mechanism involved in the interaction and incorporation of a nitrogen atom into the silicon surface. Structures with quartet and doublet spin symmetry were studied, being their mechanisms very similar, with the nitrogen atom interacting initially with one silicon dimer; after that two other structures can be formed, one with the nitrogen bonded to two silicon dimers, and the other with the nitrogen bonded to one silicon dimer and two internal silicons. This last structure corresponds to the most stable species. The results show clearly that the reaction is very favorable energetically. The use of geometrical constraints during the optimization was questioned since it prevents the proper relaxation of the silicon atoms in the first and second layers.

Un protocole expérimental a été développé dans cette thèse pour étudier l'influence de la microstructure héritée du procédé de fonderie dit Procédé à Modèle Perdu sur le comportement en fatigue oligocyclique des alliages Al-Si à température ambiante. Dans un premier temps, la microstructure des alliages étudiés a été caractérisée à la fois en 2D et en 3D. Les éprouvettes les plus appropriées et les plus représentatives et les régions d’intérêt où le suivi in-situ est réalisé (ROIs) ont été sélectionnées par une caractérisation préliminaire en tomographie aux rayons X. Cette caractérisation 3D est également nécessaire pour comprendre les mécanismes d’endommagement après rupture de l’éprouvette. Les observations in-situ réalisées en surface en utilisant un microscope longue distance (Questar) et en volume avec la tomographie aux rayons X permettent de suivre l’amorçage et la propagation des fissures et ainsi d'identifier la relation entre les mécanismes d’endommagement et les microstructures moulées. Les champs de déplacement et de déformation en 2D/3D mesurés à l'aide de la Corrélation d'Images Numériques et la Corrélation d’Images Volumiques permettent d'analyser la relation entre les champs mesurés et les mécanismes d'endommagement. L'analyse post-mortem et la simulation éléments finis ont permis de compléter l’analyse des mécanismes d’endommagement. Les grands pores favorisent l'amorçage de fissures car ils augmentent fortement le niveau de contrainte locale. Les inclusions dures (phase Si, intermétalliques au fer et phases au cuivre) jouent un rôle important dans l’amorçage et la propagation des fissures en raison des localisations de déformation sur ces inclusions / An experimental protocol was developed in this thesis in order to study the influence of casting microstructure on the fatigue behavior in Lost Foam Casting Al-Si alloys in tension and in Low Cycle Fatigue at room temperature. First of all, the microstructures of studied alloys were thoroughly characterized both in 2D and in 3D. The most suitable and representative specimens and Region of Interest (ROIs) where the in-situ monitoring was performed were selected through a preliminary characterization using X-ray tomography, which is also necessary to understand damage mechanisms after failure. In-situ observations performed on surface using Questar long distance microscope and in volume using X-ray tomography allow following cracks initiations and their propagations and thus allow identifying the relation between damage mechanisms and casting microstructure. 2D/3D displacement and strain fields measured using Digital Image Correlation and Digital Volume Correlation allows analyzing the relation between measured fields and damage mechanisms. Postmortem analysis and FEM simulation gave more information for the damage mechanisms. Large pores favor crack initiation as they strongly increase local stress level. Hard inclusions (Si phase, iron intermetallics and copper containing phases) also play an important role in crack initiation and propagation due to strain localizations at these inclusions

The present dissertation has the intention to establish how measured Sartre obtains to surpass the solipsism of the conscience, interpreting the registers that compose the phenomenological concept of Looking at, in The Being and the Nothing. After to define the concept of solipsism, will be in evidence the problem that it implies and that, according to Sartre, is originated from the notion of Cartesian Cogito. It is manifested the construction of conceptual-description of the notion of Looking at and the paper that this concept plays in the measure that offers a not cognitive evidence of the Other s existence. There are evaluated the contributions and obstacles of the concept s use of Looking at in the Sartrean attempt of overcoming the solipsism. Concluding, it is verified the reach of this Cogito extended , as Sartre calls to the experience of Looking at. From a phenomenological point of view, it results evident that the solipsism is a false problem and that the Other exists without no doubt. Ontologically, is more difficult to have this certainty, therefore Sartre does not resign to the starting point of Cogito. / O texto discute em que medida Sartre consegue superar o solipsismo da consciência, interpretando os registros que compõem o conceito fenomenológico de Olhar, em O Ser e o Nada. Após definir o conceito de solipsismo, ficará em evidência a problemática que este implica e que, segundo Sartre, origina-se da noção de Cogito cartesiano. Mostra-se a construção histórico-conceitual da noção de Olhar e o papel que este conceito joga na medida que oferece uma evidência não cognitiva da existência do Outro. Avaliam-se as contribuições e malogros do uso do conceito de Olhar na tentativa sartreana de superação do solipsismo. Em conclusão, indica-se o alcance desse Cogito ampliado , como Sartre chama à experiência do Olhar. Fenomenologicamente, a existência do Outro resulta evidente. Porém, não se dá a mesma certeza no nível ontológico. Isso exigiria sair do Cogito, como ponto de partida do filosofar, mas Sartre não abre mão dessa perspectiva.