868 resultados para Chain of custody of traces


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We explore the thesis that tall structures can be protected by means of seismic metamaterials. Seismic metamaterials can be built as some elements are created over soil layer with different shapes, dimensions, patterns and from different materials. Resonances in these elements are acting as locally resonant metamaterials for Rayleigh surface waves in the geophysics context. Analytically we proved that if we put infinite chain of SDOF resonator over the soil layer as an elastic, homogeneous and isotropic material, vertical component of Rayleigh wave, longitudinal resonance of oscillators will couple with each other, they would create a Rayleigh bandgap frequency, and wave will experience attenuation before it reaches the structure. As it is impossible to use infinite chain of resonators over soil layer, we considered finite number of resonators throughout our simulations. Analytical work is interpreted using finite element simulations that demonstrates the observed attenuation is due to bandgaps when oscillators are arranged at sub-wavelength scale with respect to the incident Rayleigh wave. For wavelength less than 5 meters, the resulting bandgaps are remarkably large and strongly attenuating when impedance of oscillators matches impedance of soil. Since longitudinal resonance of SDOF resonator are proportional to its length inversely, a formed array of resonators that attenuates Rayleigh waves at frequency â¤10 Hz could be designed starting from vertical pillars coupled to the ground. Optimum number of vertical pillars and their interval spacing called effective area of resonators are investigated. For 10 pillars with effective area of 1 meter and resonance frequency of 4.9 Hz, bandgap frequency causes attenuation and a sinusoidal impulsive force illustrate wave steering down phenomena. Simulation results proved analytical findings of this work.

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Le mouvement derridien de la différance marque la rupture avec l'affirmation de la métaphysique de la présence, avec l'autorité du signifié transcendantal. Dans cet univers mouvant de signifiants qui se renvoient perpétuellement les uns aux autres, la logique d'univocité se disloque. La "présence" n'est que fantomatique, s'esquissant au sein d'une chaîne ininterrompue de signifiants et se laissant toujours creuser par la marque d'un irréductible manque. Face au logocentrisme, corollaire de l'affirmation de la présence, l'écriture se veut siège et articulation de la trace, d'une origine qui ne peut être que raturée, véhicule d'une irrémédiable fêlure. La volet littéraire de la déconstruction a pour but de mettre en évidence le fonctionnement de l'"indécidabilité" du discours, soit une certaine ambivalence dans la signification qui caractérise tout texte. L'objectif principal de la présente recherche est de fournir une compréhension plus approfondie de la déconstruction en insistant sur l'ancrage langagier de tout texte. Le discours philosophique n'échappe ainsi pas au mécanisme différentiel du langage et de la dérive métaphorique. La parenté entre la perspective déconstructiviste derridienne et la conception mallarméenne du langage poétique semble frappante. La mise en oeuvre, par Mallarmé, d'une dislocation de l'espace textuel, son minutieux "creusement" du vers après renoncement à toute quête d'"Idéal", la mise en relief du leurre de l'appropriation langagière, voilà qui trouve un écho particulier dans les thèses derridiennes. La "mimésis" platonicienne se voit au travers du prisme de la "mimique" mallarméenne. La déconstruction poursuit son travail de "luxation" de l'oreille philosophique, insérant les philosophèmes dans la matrice langagière, les livrant ainsi au hasard du cheminement textuel et les confrontant à l'aporie. La philosophie n'a alors d'autre choix que d'abandonner ses prétentions transcendantales. La marche de la "différance" instaure une inexorable distance qui prive le sujet de tout rapport direct avec une origine assurée et lui ôte toute possibilité de maîtrise sur le monde. Au travers de la langue, se profile la question de l'altérité, de la relation dissymétrique qui nous lie à cet "autre", ce "tout-autre" qui nous fonde et nous constitue. L'accueil inconditionnel de cette altérité nous mènera à l'étude de la "religion", la déconstruction se tournant vers le "religieux" tout en effectuant un "retournement" habile de tout credo essentialiste.

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We present a reformulation of the hairy-probe method for introducing electronic open boundaries that is appropriate for steady-state calculations involving nonorthogonal atomic basis sets. As a check on the correctness of the method we investigate a perfect atomic wire of Cu atoms and a perfect nonorthogonal chain of H atoms. For both atom chains we find that the conductance has a value of exactly one quantum unit and that this is rather insensitive to the strength of coupling of the probes to the system, provided values of the coupling are of the same order as the mean interlevel spacing of the system without probes. For the Cu atom chain we find in addition that away from the regions with probes attached, the potential in the wire is uniform, while within them it follows a predicted exponential variation with position. We then apply the method to an initial investigation of the suitability of graphene as a contact material for molecular electronics. We perform calculations on a carbon nanoribbon to determine the correct coupling strength of the probes to the graphene and obtain a conductance of about two quantum units corresponding to two bands crossing the Fermi surface. We then compute the current through a benzene molecule attached to two graphene contacts and find only a very weak current because of the disruption of the Ï conjugation by the covalent bond between the benzene and the graphene. In all cases we find that very strong or weak probe couplings suppress the current.

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AbstractâThis paper presents PORBS, a parallelised observation-based slicing tool. The tool itself is written in Java making it platform independent and leverages the build chain of the system being sliced to avoid the need to replicate complex compiler analysis. The target audience of PORBS is software engineers and researchers working with and on tools and techniques for software comprehension, debugging, re-engineering, and maintenance.

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A gestão de um armazém de componentes de uma qualquer empresa produtiva é uma das principais tarefas a desempenhar no seio desta, pois a mesma afecta toda a cadeia de abastecimento de entrega do produto final, sendo o armazém de componentes o início da cadeia interna. Qualquer dificuldade que surja no desenrolar das actividades associadas poderá causar impactos prejudiciais nos processos consequentes. A melhoria do principal processo do armazém, correspondente à satisfação dos pedidos de material dos processos a jusante, é algo que trará benefícios a toda a cadeia, ao mesmo tempo que são melhoradas as condições de trabalho, eliminando o desperdício e tornando o processo mais eficiente. Não obstante deste processo, ainda existe a necessidade de recolher e gerir informações referentes aos diferentes processos do armazém da maneira mais rápida possível, para actuar de acordo com as necessidades. A falta de informação relativamente ao estado de um processo também poderá influenciar os processos seguintes de forma negativa. O projecto aqui apresentado foi realizado no armazém de componentes da Bosch Termotecnologia S.A., em Aveiro, tendo como objectivo mostrar a importância da movimentação de material e também de informação dentro desta área, criando ao mesmo tempo a melhoria tanto dos fluxos de material como dos fluxos de informação. Serão apresentadas diferentes implementações que foram desenvolvidas com o intuito de criar melhoria nos fluxos: a criação de novos fluxos de informação para o processo de recepção de material, com o intuito de recolher informação que até agora não era perceptível, para depois actuar na melhoria do processo; a criação de áreas dedicadas dentro da área de picking, de modo a atingir uma redução no número de colaboradores afectos ao processo de picking; a implementação de uma célula de repacking, de modo a remover esta actividade do processo de picking; bem como todas as actividades realizadas com o objectivo de implementar as melhorias propostas.

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The Brexit vote was a financial thunderclap for the entire Western chain of globalised finance. The EU and the Eurozone now face an unknown period of disintegration, instability and rebranding.

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Due to diminishing petroleum reserves, unsteady market situation and the environmental concerns associated with utilization of fossil resources, the utilization of renewables for production of energy and chemicals (biorefining) has gained considerable attention. Biomass is the only sustainable source of organic compounds that has been proposed as petroleum equivalent for the production of fuels, chemicals and materials. In fact, it would not be wrong to say that the only viable answer to sustainably convene our future energy and material requirements remain with a bio-based economy with biomass based industries and products. This has prompted biomass valorization (biorefining) to become an important area of industrial research. While many disciplines of science are involved in the realization of this effort, catalysis and knowledge of chemical technology are considered to be particularly important to eventually render this dream to come true. Traditionally, the catalyst research for biomass conversion has been focused primarily on commercially available catalysts like zeolites, silica and various metals (Pt, Pd, Au, Ni) supported on zeolites, silica etc. Nevertheless, the main drawbacks of these catalysts are coupled with high material cost, low activity, limited reusability etc. â all facts that render them less attractive in industrial scale applications (poor activity for the price). Thus, there is a particular need to develop active, robust and cost efficient catalytic systems capable of converting complex biomass molecules. Saccharification, esterification, transesterification and acetylation are important chemical processes in the valorization chain of biomasses (and several biomass components) for production of platform chemicals, transportation fuels, food additives and materials. In the current work, various novel acidic carbons were synthesized from wastes generated from biodiesel and allied industries, and employed as catalysts in the aforementioned reactions. The structure and surface properties of the novel materials were investigated by XRD, XPS, elemental analysis, SEM, TEM, TPD and N2-physisorption techniques. The agro-industrial waste derived sulfonic acid functionalized novel carbons exhibit excellent catalytic activity in the aforementioned reactions and easily outperformed liquid H2SO4 and conventional solid acids (zeolites, ion-exchange resins etc). The experimental results indicated strong influence of catalyst pore-structure (pore size, pore-volume), concentration of âSO3H groups and surface properties in terms of the activity and selectivity of these catalysts. Here, a large pore catalyst with high âSO3H density exhibited the highest esterification and transesterification activity, and was successfully employed in biodiesel production from fatty acids and low grade acidic oils. Also, a catalyst decay model was proposed upon biodiesel production and could explain that the catalyst loses its activity mainly due to active site blocking by adsorption of impurities and by-products. The large pore sulfonated catalyst also exhibited good catalytic performance in the selective synthesis of triacetin via acetylation of glycerol with acetic anhydride and out-performed the best zeolite H-Y with respect to reusability. It also demonstrated equally good activity in acetylation of cellulose to soluble cellulose acetates, with the possibility to control cellulose acetate yield and quality (degree of substitution, DS) by a simple adjustment of reaction time and acetic anhydride concentration. In contrast, the small pore and highly functionalized catalysts obtained by hydrothermal method and from protein rich waste (Jatropha de-oiled waste cake, DOWC), were active and selective in the esterification of glycerol with fatty acids to monoglycerides and saccharification of cellulosic materials, respectively. The operational stability and reusability of the catalyst was found to depend on the stability of âSO3H function (leaching) as well as active site blocking due to adsorption of impurities during the reaction. Thus, our results corroborate the potential of DOWC derived sulfated mesoporous active carbons as efficient integrated solid acid catalysts for valorization of biomass to platform chemicals, biofuel, bio-additive, surfactants and celluloseesters.

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The main thesis of this article is that the increasing recourse to the use of unmanned aerial systems in asymmetric warfare and the beginning routinization of U.S. drone operations represent part of an evolutionary change in the spatial ordering of global politics -- Using a heuristic framework based on actor-network theory, it is argued that practices of panoptic observation and selective airstrikes, being in need of legal justification, contribute to a reterritorialization of asymmetric conflicts -- Under a new normative spatial regime, a legal condition of state immaturity is constructed, which establishes a zone of conditional sovereignty subject to transnational aerial policing -- At the same time, this process is neither a deterministic result of the new technology nor a deliberate effect of policies to which drones are merely neutral instruments -- Rather, military technology and political decisions both form part of a long chain of action which has evolved under the specific circumstances of recent military interventions

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The Brazilian agricultural research agency has, over the years, contributed to solve social problems and to promote new knowledge, incorporating new advances and seeking technological independence of the country, through the transfer of knowledge and technology generated. However, the process of transfering of knowledge and technology has represented a big challenge for public institutions. The Embrapa is the largest and main brazilian agricultural research company, with a staff of 9.790 employees, being 2.440 researchers and an annual budget of R$ 2.52 billion. Operates through 46 decentralized research units, and coordinate of the National Agricultural Research System - SNPA. Considering that technology transfer is the consecration of effort and resources spent for the generation of knowledge and the validity of the research, this work aims to conduct an assessment of the performance of Embrapa Swine and Poultry along the production chain of broilers and propose a technology transfer model for this chain, which can be used by the Public Institutions Research â IPPs. This study is justified by the importance of agricultural research for the country, and the importance of the institution addressed. The methodology used was the case study with a qualitative approach, documentary and bibliographic research and interviews with use of semi-structured questionnaires. The survey was conducted in three stages. In the first stage, there was a diagnosis of the Technology Transfer Process (TT), the contribution of the Embrapa Swine and poultry for the supply chain for broiler. At this stage it was used bibliographical and documentary research and semi- structured interviews with agroindustrial broiler agents, researchers at Embrapa Swine and Poultry, professionals of technology transfer, from the Embrapa and Embrapa Swine and Poultry, managers of technology transfer and researchers from the Agricultural Research Service - ARS. In the second step, a model was developed for the technology transferring poultry process of Embrapa. In this phase, there were made documentary and bibliographic research and analysis of information obtained in the interviews. The third phase was to validate the proposed model in the various sectors of the broilers productive chain. The data show that, although the Embrapa Swine and Poultry develops technologies for broiler production chain, the rate of adoption of these technologies by the chain is very low. It was also diagnosed that there is a gap between the institution and the various links of the chain. It was proposed an observatory mechanism to approximate Embrapa Swine and Poultry and the agents of the broiler chain for identifying and discussing research priorities. The proposed model seeks to improve the interaction between the institution and the chain, in order to identify the chain real research demands and the search and the joint development of solutions for these demands. The proposed TT model was approved by a large majority (96.77%) of the interviewed agents who work in the various links in the chain, as well as by representatives (92%) of the entities linked to this chain. The acceptance of the proposed model demonstrates the willingness of the chain to approach Embrapa Swine and Poultry, and to seek joint solutions to existing problems.

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American visceral leishmaniasis is a zoonosis caused by Leishmania infantum and transmitted by the bite of the sand flies Lutzomia longipalpis.The main domestic reservoir is the dog, while foxes and opposums are the known wild reservoirs. However, identification of natural infections with L. infantum in rodents appears for need of investigating the participation of these rodents how source of infection of the parasite. In the present work the Leishmania infantum infection was investigated in rodents captured in Rio Grande do Norte, aiming at to offer subsidies to the understanding of the epidemic chains of LVA in the State. Thirteen Galea spixii were distributed in four groups, being G1 the group control with four animals and the others, G2, G3 and G4, with three animals each. Those animals were intraperitoneally inoculated with 107 promastigotas of L. infantum and accompanied for, respectively, 30, 90 and 180 days. Weekly the animals were monitored as for the corporal weight and rectal temperature. At the end of each stipulated period the animals were killed. Blood were used for determination of the parameters biochemical and haematological, PCR, ELISA, microscopic examination and cultivation in NNN medium. Liver, spleen and lymph node were used in Giemsa-stained impression and cultivation in NNN medium. Liver and spleen fragments were still used in PCR and histopathological, respectively. At the same time 79 rodents of the species Rattus rattus, Bolomys lasiurus, Oligoryzomys nigripis, Oryzomys subflavus and Trichomys apereoides were captured in the Municipal districts of Brejinho, Campo Grande, Coronel Ezequiel, Passa e Fica and Vázea for identification of natural infection with L. infantum. Evidence of infection was checked by direct examination of Giemsa-stained impression of liver, spleen and blood and culture of these tissues in NNN medium. Antibodies were researched by ELISA. They were not found differences among the weigh corporal final, rectal temperature and biochemical and haematological parameters of the Galea spixii controls and infected. The rectal temperature of the animals varied from 36OC to 40OC. For the first time values of the haematocrit (33,6% to 42,8%), hemoglobin (10,2 to 14,5g/dl), erythrocyts number (4,67x106 to 6,90x106/mm3), total leukocytes (0,9x103 to 9,2x103/mm3), platelets (49x103 to 509x103/mm3) total proteins (1,56 to 6,06 g/dl), albumin (1,34 to 3,05 g/dl) and globulins (0,20 to 3,01 g/dl) of the Galea spixii were determined. The lymphocytes were the most abundant leucocytes. Infection for L. infantum was diagnosed in two animals euthanasied 180 days after the infection. In one of the animals was also identified antibodies anti-Leishmania. The parasite was not found in none of the five other species of rodents captured. Galea spixii are resistant to the infection for L. infantum and they are not good models for the study for visceral leishmaniose, although they can act as infection sources. More studies are necessary to determine the paper of the rodents in the epidemic chain of transmission of the visceral leishmaniose in the State of Rio Grande do Norte

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Die Gesteine des bearbeiteten Aufschlusses, dem Naturdenkmal "Saurierfährten Münchehagen" bei Münchehagen (Rehburger Berge), liegen stratigraphisch in der Bückeberg-Formation des Berrias (Wealden). Aufgeschlossen ist der Hauptsandstein (Wealden 3) . Es werden die Sedimenttexturen der Sohlbankfläche des ehemaligen Steinbruchs analysiert und interpretiert. Vorherrschende Schichtungstypen sind Wellenrippelschichtung und Flaserschichtung. Die Sedimente sind stark bioturbat. Auf mehreren freiliegenden Flächenniveaus der Sohlbank sind Rip- pelmarken zu beobachten, die systematisch vermessen wurden. Danach handelt es sich uro Wellenrippeln und untergeordnet um strÃmungsüberformte Wellenrippeln durch ablaufendes Wasser. Zahlreiche Merkmale zeigen wiederholtes Auftauchen und Trok- kenfallen an. Tonlagen kennzeichnen zeitweilige Stillwasserbedingungen. Ein ehemals verzweigtes Rinnensystem ist in Relikten erhalten und beweist ebenfalls einen wechselnden Wasserstand (ablaufendes Wasser). Sporadisch kam es im Zuge hochenergetischer Ereignisse zu einem schichtflutartigen Abfließen des Wassers. Eine reiche Ichnofauna ist zu beobachten. Wenige Spurentypen sind vorhanden, die Spurendichte ist jedoch sehr hoch. Es dominieren horizontale oder wenig geneigte Gestaltungswühlgefüge, vertikale Bauten kommen nur untergeordnet vor. Als häufigste Spurentypen treten Thalassinoides, Muensteria, Plano- lites und Pelecypodichnus auf. Die GrÃße der Ichnofossilien ist meist gering. Die Spuren bilden eine Ichnocoenose aus Ichnofossilien der Cruziana- und untergeordnet der Skolithos- Fazies. Bivalven belegen Brackwasser-Verhältnisse. Dies alles sind Merkmale eines lagunären Ablagerungsraumes, gelegen am Rand eines gezeitenarmen bzw. -losen Nebenmeeres (Niedersächsisches Becken) im Ãœbergang von der fluviatilen in die litorale Fazies im rückwärtigen Bereich eines Barrierensystems. Wahrscheinlich spielte Wind eine entscheidende Rolle als Ursache für Wasserspiegelschwankungen. Die maximale Wassertiefe bei auflandigem Sturm hat vermutlich nicht mehr als 3 - 4 m betragen. Sonst war sie wahrscheinlich deutlich geringer und ermÃglichte Dinosauriern ein Durchwaten des Gewässers, wie Fährten auf der Sohlfläche beweisen.

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A dificuldade em conhecer o histórico de temperatura de um alimento, desde sua produção até o consumo, torna difícil prever sua verdadeira vida-útil. O uso de indicadores de tempo e temperatura (ITT) pode ser uma alternativa inovadora empregada para garantir a validade de produtos de forma dinâmica. Assim, este trabalho visa desenvolver novos indicadores enzimáticos de tempo e temperatura para monitorar a qualidade de alimentos perecíveis durante o seu processamento e armazenamento, baseados na reação de complexação entre o amido e o iodo (azul), e na posterior atuação de uma enzima amilase sobre esse complexo, para causar uma redução da intensidade da cor azul a uma taxa dependente do tempo e da temperatura de armazenagem. Os sistemas inteligentes propostos possuem versatilidade de atuação em função do tipo e quantidade de amilase empregada. Desta forma, foi utilizada uma amilase termoestável para a formulação de um indicador inteligente de processamento, utilizado para o controle de tratamentos térmicos industriais (pasteurização);e uma amilase termosensível na formulação de um indicador de armazenamento, empregada para o controle das condições de temperatura durante a cadeia de frio de produtos perecíveis. Na elaboração dos ITT de processamento foram realizadas simulações em laboratório e testes em planta fabril, os quais avaliaram diferentes concentrações de amilase termoestável nos protótipos de ITT quando submetidos as condições de tempo e temperatura de pasteurização. Os resultados evidenciaram que a resposta de cor dos indicadores foi visualmente interpretada, como adaptável à medição usando equipamentos, apresentando boa reprodutibilidade em todas as condições estudadas. O ITT contendo 6,5 % de amilase termoestável (penzima/pamido) foi aquele cujo resultado melhor se adequou à utilização na validação de cozimento de presunto. Nesta condição, o protótipo anexado à embalagem primária do produto indicou o processo de pasteurização de forma fácil, precisa e não destrutiva. Já durante o desenvolvimento do ITT de armazenamento foram realizadas simulações em laboratório, testes em planta fabril e ponto de venda, os quais avaliaram o uso de diferentes concentrações de amilase termosensível nos protótipos de ITT quando submetidos a diversas condições de cadeia de frio. Os resultados evidenciaram que devido à possibilidade de definir a vida-útil destes protótipos variando as concentrações de enzima termosensível, os indicadores podem ser facilmente adaptados para controlar as condições de temperatura durante a cadeia de diversos alimentos perecíveis. O protótipo contendo 60 % de amilase termosensível (penzima/pamido) foi aquele cujo resultado melhor se adequou à utilização no controle da cadeia avícola. Assim, o ITT indicou visualmente o histórico de tempo e temperatura de produtos à base de frango de forma fácil e precisa. Os resultados obtidos na avaliação das percepções dos consumidores frente ao emprego de indicadores inteligentes em embalagens alimentícias mostraram que o uso de ITT é uma inovação receptiva, com consequente aceitação e intenção de compra elevada pela população brasileira. Assim, com este trabalho espera-se contribuir efetivamente para que o conceito de embalagens inteligentes possa ser aceito comercialmente e que sejam estabelecidas no Brasil normas que regulamentem seu uso, conferindo benefícios à conservação de grande variedade de alimentos.

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Le mouvement derridien de la différance marque la rupture avec l'affirmation de la métaphysique de la présence, avec l'autorité du signifié transcendantal. Dans cet univers mouvant de signifiants qui se renvoient perpétuellement les uns aux autres, la logique d'univocité se disloque. La "présence" n'est que fantomatique, s'esquissant au sein d'une chaîne ininterrompue de signifiants et se laissant toujours creuser par la marque d'un irréductible manque. Face au logocentrisme, corollaire de l'affirmation de la présence, l'écriture se veut siège et articulation de la trace, d'une origine qui ne peut être que raturée, véhicule d'une irrémédiable fêlure. La volet littéraire de la déconstruction a pour but de mettre en évidence le fonctionnement de l'"indécidabilité" du discours, soit une certaine ambivalence dans la signification qui caractérise tout texte. L'objectif principal de la présente recherche est de fournir une compréhension plus approfondie de la déconstruction en insistant sur l'ancrage langagier de tout texte. Le discours philosophique n'échappe ainsi pas au mécanisme différentiel du langage et de la dérive métaphorique. La parenté entre la perspective déconstructiviste derridienne et la conception mallarméenne du langage poétique semble frappante. La mise en oeuvre, par Mallarmé, d'une dislocation de l'espace textuel, son minutieux "creusement" du vers après renoncement à toute quête d'"Idéal", la mise en relief du leurre de l'appropriation langagière, voilà qui trouve un écho particulier dans les thèses derridiennes. La "mimésis" platonicienne se voit au travers du prisme de la "mimique" mallarméenne. La déconstruction poursuit son travail de "luxation" de l'oreille philosophique, insérant les philosophèmes dans la matrice langagière, les livrant ainsi au hasard du cheminement textuel et les confrontant à l'aporie. La philosophie n'a alors d'autre choix que d'abandonner ses prétentions transcendantales. La marche de la "différance" instaure une inexorable distance qui prive le sujet de tout rapport direct avec une origine assurée et lui ôte toute possibilité de maîtrise sur le monde. Au travers de la langue, se profile la question de l'altérité, de la relation dissymétrique qui nous lie à cet "autre", ce "tout-autre" qui nous fonde et nous constitue. L'accueil inconditionnel de cette altérité nous mènera à l'étude de la "religion", la déconstruction se tournant vers le "religieux" tout en effectuant un "retournement" habile de tout credo essentialiste.

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The delicate balance between the production and disposal of proteins is vital for the changes required in the cell to respond to given stimulus. Ubiquitination is a protein modification with a range of signaling outcomes when ubiquitin is attached to a protein through a highly ordered enzymatic cascade process. Understanding ubiquitination is a growing field and nowadays the application of chemical reactions allows the isolation of quantitative materials for structural studies. Therefore, in this dissertation it is described some of these suitable chemical methodologies to produce an isopeptide bond toward the polymerization of ubiquitin bypassing the enzymatic control with the purpose of showing if these chemical modifications have a direct impact on the structure of ubiquitin. First, the possibility of incorporating non-natural lysine analogs known as mercaptolysines into the polypeptide chain of Ubiquitin was explored when they were attached to ubiquitin by native chemical ligation at its C terminus. The sulfhydryl group was used for the attachment of a paramagnetic label to map the surface of ubiquitin. Second, the condensation catalyzed by silver nitrate was used for the dimer assembly. In particular, the main focus was on examining whether orthogonal protection and deprotection of each monomer have an impact on the reaction yield, since the synthetic strategy has been previously attempted successfully. Third, the formation of ubiquitin dimers was approached by building an inter-ubiquitin linkage mimicking the isopeptide bond with two approaches, the classic disulfide exchange as well as the thiol-ene click reaction by thermal initiation in aqueous conditions. After assembling the dimeric units, they were studied by Nuclear Magnetic Resonance, in order to establish a conformational state profile which depends on the pH conditions. The latter is a very important concept since some ligands have a preferred affinity when the protein-protein hydrophobic patches are in close proximity.

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Dissertação (mestrado)âUniversidade de Brasília, Faculdade de Arquitetura e Urbanismo, Programa de Pós-Graduação em Arquitetura e Urbanismo, 2015.