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O objetivo central desta tese é estudar o percurso artístico e intelectual de Leon Hirszman a partir dos filmes Que país é este? (1976-77), ABC da greve (1979- 90) e Eles não usam black-tie (1981). Discutindo as relações entre cinema e História, a pesquisa se concentra nas práticas culturais, estéticas e ideológicas do realizador, procurando analisar as interpretações que ele mobilizou em torno do Brasil durante a vigência do regime militar. A despeito de Hirszman ter consolidado a sua trajetória como integrante do Cinema Novo, questão que percorre as páginas deste doutorado, propõe-se também uma aproximação entre a sua obra e o projeto dramatúrgico construído por autores oriundos do Teatro de Arena. Na década de 1970, face à crise que se instalou no campo cultural da esquerda, em especial o colapso da crença revolucionária anterior a 1964 e o refluxo da leitura do povo como vanguarda heroica para uma transformação do mundo, o cineasta se aproximaria do revisionismo artístico proposto, principalmente, por Gianfrancesco Guarnieri, Paulo Pontes e Vianinha. Mantendo em seus filmes uma abordagem politizada da classe popular, sem abdicar da figura do intelectual como mediador de denúncias contra a ditadura, o diretor se voltaria para uma produção em sintonia com o viés comunista de engajamento, em diálogo com a tradição do realismo crítico e disposta a elaborar narrativas e registros documentais em confronto ao autoritarismo dos militares. Nesse sentido, mesmo sem partilhar do ideário do novo sindicalismo surgido sobretudo entre os metalúrgicos da cidade paulista de São Bernardo do Campo, Hirszman deslocaria a figura do operário para o centro do processo criativo de ABC da greve e de Black-tie, representando-o em uma chave próxima à resistência articulada pelo Partido Comunista Brasileiro (PCB), na qual o trabalhador seria visto como parte de uma ampla frente organizada para superar a ditadura e atuar em prol da redemocratização. Uma obra realizada com o intuito de responder aos dilemas sociais de seu contexto histórico, a propor uma abordagem particular sobre a classe popular e a militância antiautoritária, a partir de leituras e experiências estéticas construídas em meio aos impasses que percorreram a esquerda política e cultural na segunda metade dos anos 1970. / The main goal of this thesis is to study Leon Hirszman\'s artistic and intellectual trajectory through the films Que país é este? (1976-77), ABC da greve (1979-90) and They don\'t wear black-tie (1981). Discussing the relation between film and History, the research concentrates itself on the cultural, aesthetic and ideological practices of the director, aiming to analyze his interpretations about Brazil during its military dictatorship. Despite Hirszman\'s consolidated career as a member of the Cinema Novo movement, issue that is described during this doctoral thesis, it also proposes an approach of his work with the dramaturgical project originated by authors from the Teatro de Arena. On the 1970\'s, in virtue of the crisis installed in the left wing\'s cultural sphere, specially the collapse of the revolutionary belief preceding 1964 and the retrocession of the interpretation placing the people as the heroic vanguard leading a structural transformation, the filmmaker would court the artistic revisionism proposed by Gianfrancesco Guarnieri, Paulo Pontes and Vianinha. Maintaining a politicized approach about the popular class on his films, without abdicating the image of the intellectual as a mediator of denounces against the dictatorship, the director would proceed to a production in tune with the communist\'s active participation project, establishing a dialogue with the tradition of critical realism, willing to elaborate narratives and documental registers confronting with the authoritarian way of the military. In this sense, even without sharing the ideology originated from the newly born trade unionism, especially among the steelworkers from São Bernardo do Campo\'s city, Hirszman shifted the figure of the worker, making it the core of the creative process of ABC da greve and Black-tie. In these movies, it was represented as a key-piece close to the resistance articulated by the Brazilian Communist Party (PCB), in which it was seen as part of a large front, organized to overcome the military regime and act in favor of the country\'s redemocratization. A work realized with the intention of responding to the social dilemmas of its time, proposing a singular approach about the popular class and the anti-authoritarian militancy, originating interpretations and aesthetic experiences constructed among conflicts that filled the left-wing politic and cultural manifestations on the second half of the seventies.

Le processus de recombinaison V(D)J des gènes d’immunoglobulines (Ig) est caractérisé par une grande imprécision des jonctions entre les segments variables (V), de diversité (D) et de jonction (J). Deux fois sur trois, un décalage du cadre de lecture apparaît, aboutissant à une jonction non productive dite « hors phase ». Plusieurs études ont démontré que les deux allèles productifs et non-productifs sont activement transcrits. Les transcrits matures issus des allèles non-productifs sont pris en charge par un mécanisme de surveillance des ARNm appelé NMD « Nonsense-Mediated mRNA Decay ». En dégradant efficacement les ARNm d’Ig contenant des codons non-sens, ce mécanisme prévient l’apparition des Ig tronquées au cours de l’ontogénie B. Néanmoins, aucune étude n’a jusqu’ici analysé l’impact de l’épissage alternatif des transcrits d’Ig non-productifs. Ce phénomène appelé NAS « Nonsense-associated Altered Splicing » peut conduire à une production d’Ig tronquées présentant des délétions internes du domaine variable (V).Les projets développés lors de cette thèse ont montré que la présence d’un codon non-sens, au niveau de l’exon variable (VJ) des transcrits Igκ, favorise le saut d’exon et la production de chaînes légères dépourvues de domaine variable (ΔV-κLCs). De façon intéressante, ces Ig tronquées provoquent un stress cellulaire et conduisent à l’apoptose des plasmocytes (Article 1). Ces observations ont permis d’identifier un nouveau point de contrôle agissant tardivement lors de la différenciation plasmocytaire : le TIE « Truncated-Ig Exclusion » checkpoint. Ce processus de contrôle provoque l’élimination des plasmocytes qui produisent des chaînes d’Ig tronquées. Nous avons également étudié l’épissage alternatif des transcrits d’Ig non-productifs en l’absence de TIE-checkpoint (Article 2). Cette étude a révélé que l’hypertranscription des gènes d’Ig dans les plasmocytes favorise l’épissage alternatif des transcrits d’Ig non-productifs. En utilisant un modèle d’expression forcée d’Ig tronquées, nous avons mis en évidence une coopération entre les mécanismes assurant la surveillance des ARNm (NMD) et la surveillance au niveau protéique (UPR : « Unfolded Protein Response », autophagie) (Article 3). Sur la base de ces résultats, nous avons mis au point une nouvelle approche thérapeutique qui consiste à forcer la production d’Ig tronquées en utilisant des oligonucléotides anti-sens (AON) capables de provoquer l’élimination de l’exon variable lors de l’épissage. Cette invention pourrait ouvrir des perspectives thérapeutiques pertinentes dans le traitement du Myélome Multiple et d’autres pathologies touchant les plasmocytes. / The recombination process V(D)J of immunoglobulin (Ig) genes is characterized by random junctions between the variable (V), diversity (D) and joining (J) segments. A frameshift mutation appears in two-third of cases, generating a non-productive or « out of frame » junction. Several studies have shown that both productive and non-productive alleles are actively transcribed. The mature transcripts from nonproductive alleles are usually considered sterile and innocuous as a result of an mRNA surveillance mechanism called NMD « Nonsense-Mediated mRNA Decay ». By degrading aberrant mRNA, this mechanism prevents the appearance of truncated Ig during B cell ontogeny. However, less is known about the impact of alternative splicing on non-productive Ig transcripts. This mechanism, called NAS « Nonsense-associated Altered Splicing » can lead to the production of truncated Ig with internal deletions of variable domain (V). During my thesis, we have shown that the presence of a stop codon, within the variable exon (VJ) of Igκ transcripts, promotes exon skipping and synthesis of V domain-less κ light chains (ΔV-κLCs). Interestingly, such truncated Ig causes cellular stress and leads to plasma cells apoptosis (Article 1). These findings have identified a new checkpoint acting late during plasma cell differentiation: TIE « Truncated-Ig Exclusion » checkpoint. This process ensures counter-selection of plasma cells producing truncated-Ig. We also studied the alternative splicing of non-productive Ig transcripts in the absence of TIE-checkpoint (Article 2). We found that hypertranscription of Ig genes in plasma cells promote alternative splicing of non-productive Ig transcripts. Using a model forcing the expression of truncated Ig, we identified a cooperative action between mRNA surveillance mechanisms (NMD) and those of protein surveillance (UPR « Unfolded Protein Response », autophagy) (Article 3). Based on these results, we have developed a new therapeutic approach by increasing the production of truncated Ig using antisense oligonucleotides (AON) that leads to the elimination of the variable exon during splicing. This invention could open new avenues for the treatment of Multiple Myeloma patients and other pathologies affecting plasma cells.

Abstract : Deep reinforced concrete beams are commonly used as transfer girders or bridge bents, at which its safety is often crucial for the stability of the whole structure. Such elements are exposed to the aggressive environment in northern climates causing steel-corrosion problems due to the excessive use of de-icing salts. Fiber-reinforced polymers (FRP) emerged as non-corroded reinforcing materials to overcome such problems in RC elements. The present study aims to address the applicability of concrete deep beams totally reinforced with FRP bars. Ten full-scale deep beams with dimensions of 1200 × 300 × 5000 mm were constructed and tested to failure under two-point loading. Test variables were shear-span depth ratio (equal to 1.47, 1.13, and 0.83) and different configurations of web reinforcement (including vertical and/or horizontal web reinforcement). Failure of all specimens was preceded by crushing in the concrete diagonal strut, which is the typical failure of deep beams. The test results indicated that, all web reinforcement configurations employed in the tested specimens yielded insignificant effects on the ultimate strength. However, strength of specimens containing horizontal-only web reinforcement were unexpectedly lower than that of specimens without web reinforcement. The web reinforcement’s main contribution was significant crack-width control. The tested specimens exhibited reasonable deflection levels compared to the available steel-reinforced deep beams in the literature. The development of arch action was confirmed through the nearly uniform strain distribution along the length of the longitudinal reinforcement in all specimens. Additionally, the basic assumption of the strut-and-tie model (STM) was adequately used to predict the strain distribution along the longitudinal reinforcement, confirming the applicability of the STM for FRP-reinforced deep beams. Hence, a STM based model was proposed to predict the strength of FRP-reinforced deep beams using the experimental data, in addition to the available experimentally tested FRP-reinforced deep beams in the literature. Assessment of the available STMs in code provisions was conducted identifying the important parameters affecting the strut efficiency factor. The tendency of each parameter (concrete compressive strength, shear span-depth ratio, and strain in longitudinal reinforcement) was individually evaluated against the efficiency factor. Strain energy based calculations were performed to identify the appropriate truss model for detailing FRP-reinforced deep beams, hence, only four specimens with vertical web reinforcement exhibited the formation of two-panel truss model. The proposed model was capable to predict the ultimate capacity of the tested deep beams. The model was also verified against a compilation of a data-base of 172 steel-reinforced deep beams resulting in acceptable level of adequacy. The ultimate capacity and performance of the tested deep beams were also adequately predicted employing a 2D finite element program (VecTor2), which provide a powerful tool to predict the behavior of FRP-reinforced deep beams. The nonlinear finite element analysis was used to confirm some hypotheses associated with the experimental investigations. / Résumé : Les poutres profondes en béton armé (BA) sont couramment utilisées comme poutre de transfert ou coude de pont, comme quoi sa sécurité est souvent cruciale pour la sécurité de l’ensemble de la structure. Ces éléments sont exposés à un environnement agressif dans les climats nordiques causant des problèmes de corrosion de l’acier en raison de l’utilisation excessive de sels de déglaçage. Les polymères renforcés de fibres (PRF) sont apparus comme des matériaux de renforcement non corrodant pour surmonter ces problèmes dans les BA. La présente étude vise à examiner la question de l'applicabilité des poutres profondes en béton complètement renforcées de barres en PRF. Dix poutres profondes à grande échelle avec des dimensions de 1200 × 300 × 5000 mm ont été construites et testées jusqu’à la rupture sous chargement en deux points. Les variables testées comprenaient différents ratios de cisaillement porté/profondeur (égal à 1.47, 1.13 et 0.83) ainsi que différentes configurations d’armature dans l’âme (incluant un renforcement vertical avec ou sans renforcement horizontal). La rupture de tous les spécimens a été précédée par l’écrasement du béton dans le mât diagonal, ce qui est la rupture typique pour les poutres profondes en BA. Les résultats ont révélé que toutes les configurations de renforcement de l’âme employées dans les spécimens d'essais avaient un effet négligeable sur la résistance ultime. Toutefois, la résistance des spécimens contenant uniquement un renforcement horizontal était étonnamment inférieure à celle des spécimens sans renforcement. La contribution principale du renforcement de l’âme était dans le contrôle de la largeur de fissuration. Les spécimens examinés présentaient une déflexion raisonnable par rapport à ce qui est disponible pour les poutres profondes renforcées en acier dans la littérature. Le développement de l'effet d'arche a été confirmé par la distribution quasi uniforme des déformations le long du renforcement longitudinal dans tous les spécimens. En outre, l'hypothèse de base du modèle des bielles et tirants (MBT) a été utilisée adéquatement pour prédire la distribution de déformation le long du renforcement longitudinal, confirmant l'applicabilité du MBT pour les poutres profondes armées de PRF. Par conséquent, un modèle basé sur un MBT a été proposé afin de prédire la résistance des poutres profondes renforcées de PRF en utilisant les données expérimentales en plus de la mise à l'épreuve expérimentalement des poutres profondes renforcées de PRF trouvées dans la littérature. Une évaluation des MTB disponibles dans les dispositions des codes a été menée afin de déterminer les paramètres importants affectant le facteur d'efficacité de la bielle. La tendance de chaque paramètre (la résistance à la compression du béton, le ratio de cisaillement porté/profondeur, et la déformation dans le renforcement longitudinal) a été évaluée individuellement contre le facteur d'efficacité. Des calculs basés sur l’énergie des déformations ont été effectués pour identifier le modèle de treillis approprié afin de détailler les poutres profondes renforcées de PRF. Par conséquent, seulement quatre spécimens avec un renforcement vertical dans l’âme présentaient la formation de modèles avec deux panneaux de treillis. Le modèle proposé a été capable de prédire la capacité ultime des poutres profondes testées. Le modèle a également été vérifié contre une base de données de 172 poutres profondes renforcées en acier aboutissant en un niveau acceptable de pertinence. La capacité ultime et la performance des poutres profondes testées ont été également adéquatement prédites employant un programme d'éléments finis en 2D (VecTor2), ce qui fournira un puissant outil pour prédire le comportement des poutres profondes renforcées de PRF. L'analyse non linéaire par éléments finis a été utilisée afin de confirmer certaines hypothèses associées à l'étude expérimentale.

Thesis (MDram (Drama))--Stellenbosch University, 2008. / Theatre for young people (TYP) is the umbrella term for all theatre created by professional actors for the age group 2 to 25. Within this term there is a form or genre that creates theatre for the ages 13 – 18 with the specific purpose of entertaining these audiences rather than educating them through other forms such as Theatre-In-Education. The aims of this study are to firstly establish to what extent this phenomenon exist within the Western Cape and secondly, if it is found lacking to look at the challenges and opportunities that can arise when introducing this form into the market. There are three reasons why this form should be introduced into the Western Cape’s TYP market. Firstly, theatre is more than just an educational tool for younger audiences and young people deserve the same cultural rights as adults. Secondly, many industries already approach young people as a separate market and theatre needs to adopt the same approach. Lastly, theatre for the age group 13 – 18 is an important part of audience development and should be pursued if theatre wants to expand its market base. To establish what the current strengths and weaknesses of the TYP industry in the Western Cape are, an international frame of reference must be created. The government policy and TYP industry structure of four countries, namely Australia, Denmark, England and The Netherlands are used to create a broad framework from which specific TYP companies and festivals within these countries are discussed. Some general challenges facing TYP in these countries are also highlighted and these elements then form the framework for comparison. The same elements within the TYP industry of the Western Cape – government policy, the TYP industry, companies and festivals – are also discussed and then a comparison between the countries and the Western Cape is made. Based on this it becomes clear that the age group 13 – 18 is grossly neglected when it comes to theatre as form of entertainment as TYP companies in the Western Cape focus mainly on children and educational theatre. From this the challenges that face creators of TYP as entertainment within the larger South African society are highlighted and also made applicable to the Western Cape. The definition of theatre in a multicultural society, the economic situation of the country, the general attitude of society towards theatre, the problematic nature of the youth market and funding structures are identified as possible challenges for TYP in the Western Cape. There are, however, also opportunities for TYP as entertainment within the industry. By using the concept of branding and existing structures in the youth market it is possible to raise the presence of TYP as entertainment form. Youth theatre, educational institutes and the current adult festival circuit of the Western Cape are all possible platforms through which the brand of TYP as entertainment can be introduced and work in symbiosss with the current theatre industry.

Malaria remains one of the world's major health problems, especially in developing countries. A better understanding of the pathology and pathophysiology of severe malaria is key to develop new treatments. Different approaches have been used in malaria research including the in vitro co-culture models with endothelial cells and both murine and simian animal models. However these are open to controversy due to disagreement on their representativeness of human disease. Using human post-mortem tissue in malaria research is another important approach but is practically challenging, limiting the availability of post mortem samples from malaria patients. The work in this thesis had two main themes. First I examined the role of the endothelial signalling Angiopoetin-Tie-2 receptor pathway in malaria. Ang-2 has been shown to be a significant biomarker of severe and fatal malaria. I examined the tissue specific expression of proteins from this pathway in post-mortem brain tissues from fatal malaria cases, but found no difference between cerebral malaria and non-cerebral malaria cases. Ang-2 correlated with the severity of malaria in these patients. An attempt to examine the interaction of hypoxia and the Ang-Tie-2 pathway in vitro using a co-culture model of human brain endothelial cells was unsuccessful due to contamination of the cell line. The second part of the thesis aimed to utilise molecular pathology techniques including miRNA and whole-genome microarrays. I have shown for the first time that these can be successfully applied to human post-mortem tissue in malaria. First I used archival tissues to examine the microRNA signature in the kidney of patients with malaria associated renal failure. Second I optimised a protocol to preserve post mortem tissue for molecular pathology, from an autopsy study in Mozambique. Using the subsequent total mRNA transcriptomic data and bioinformatics analysis this work has expanded our knowledge of differential gene expression and the families of genes which are dysregulated in the brain in response to malaria infection.

Este trabalho estuda a interação entre os métodos anti-ilhamento aplicados em sistemas fotovoltaicos residenciais, operando simultaneamente em uma rede de distribuição de baixa tensão. Os sistemas fotovoltaicos em geral interagem entre si, com a rede de distribuição da concessionária e com outras fontes de geração distribuída. Uma consequência importante dessa interação é a ocorrência do ilhamento, que acontece quando as fontes de geração distribuída fornecem energia ao sistema elétrico de potência mesmo quando esta se encontra eletricamente isolada do sistema elétrico principal. A função anti-ilhamento é uma proteção extremamente importante, devendo estar presente em todos os sistemas de geração distribuída. Atualmente, são encontradas diversas técnicas na literatura. Muitas delas oferecem proteção adequada quando um inversor está conectado à linha de distribuição, mas podem falhar quando dois ou mais funcionam simultaneamente, conectados juntos ou próximos entre si. Dois destes métodos são analisados detalhadamente nesse estudo, avaliados em uma rede de distribuição residencial de baixa tensão. Os resultados obtidos mostram que a influência de um método sobre o outro é dependente da predominância de cada um deles dentro do sistema elétrico. Contudo, nas condições analisadas o ilhamento foi detectado dentro do limite máximo estabelecido pelas normas pertinentes. / This work studies the interaction between islanding detection methods applied in residential photovoltaic systems, operating simultaneously in a low voltage distribution network. Photovoltaic systems, in general, interact with themselves, with the utility grid and other distributed generation sources. An important consequence of this interaction is the islanding occurrence, which happens when distributed generation sources supply energy to the electrical power system even when it is electrically isolated from the main electrical system. The anti-islanding function is an extremely important protection, and should be present in all distributed generation systems. Actually, many techniques are found in the literature. Most of them provide suitable protection when one inverter is connected to the distribution line, but can fail when two or more work simultaneously, connected at the same point or close to each other. Two of these methods are analyzed in detail in this study and evaluated in a residential low voltage distribution line. The obtained results show that the influence of a method over another one is dependent of the predominance of each one within the electrical system. However, in the analyzed condition the islanding was detected within the maximum allowed time established by applicable rules.

Várias espécies de moscas-das-frutas têm sido alvo de investigações visando sua criação massal, incluindo Ceratitis capitata (Wiedemann) (mosca-do-Mediterrâneo ou medfly) e, mais recentemente, Anastrepha fraterculus (Wiedemann) (mosca-das-frutas sul americana), sendo as espécies de maior importância econômica e quarentenária em várias áreas produtoras de frutas do Brasil, Uruguai, Argentina e Peru. Um dos fatores determinantes para que a Técnica do Inseto Estéril (TIE) seja aplicada contra uma determinada praga é a existência de métodos de criação massal da espécie. Para se alcançar a criação em larga escala dessas espécies de moscas-das-frutas, é necessário, inicialmente, o preparo de uma dieta larval adequada. Como a dieta de criação pode oferecer uma quantidade enorme de substâncias nutritivas, as larvas criadas artificialmente amadurecem mais cedo do que as selvagens, o que acelera a sucessão de gerações. Essas mudanças detectadas durante o estágio larval podem formar adultos com maiores reservas nutritivas, atingindo a maturidade sexual mais cedo. Existem várias biofábricas de mosca-das-frutas no mundo capazes de produzir machos estéreis que são utilizados para a erradicação ou supressão populacional em área-ampla. Visando-se diminuir os custos de produção dos insetos, pesquisas voltadas para a otimização e desenvolvimento de novas dietas não podem parar. Portanto, os objetivos deste trabalho foram determinar a adequação e densidade larval ideal das moscas C. capitata e A. fraterculus em novas dietas à base de farinha de milho (FM), bagaço de cana-de-açúcar (BC), pó de cenoura liofilizada (PC) e carragenina (MC), escolhendo a dieta mais eficiente e viável economicamente para produção de cada uma dessas espécies com base na quantidade e qualidade de insetos produzidos e no custo de produção. As densidades larvais ideais para a criação de C. capitata nas dietas larvais FM, BC e PC foram, respectivamente, 0,5; 2,0; e 1,0 mL de ovos/kg de dieta. A dieta larval com maior produtividade foi a dieta BC, produzindo uma média de 6.514 pupas/kg de dieta, seguida das dietas FM e PC, que produziram, respectivamente, uma média de 5.018 e 4.135 pupas por kg de dieta. A ordem decrescente de viabilidade econômica entre as três dietas larvais para C. capitata foi a mesma (BC>FM>PC), sendo necessário um investimento médio de R$ 471,29; R$ 482,26; e R$ 1.085,85, respectivamente, para a produção de 1 milhão de pupas. Os resultados com A. fraterculus mostraram que as densidades larvais ideais nas dietas FM e MC foram de 2,0/kg de dieta e 1,5 mL de ovos/L de dieta, respectivamente. A dieta larval PC foi considerada inviável devido à baixa produtividade e peso de pupas. Em termos de produtividade, a dieta larval MC (produção média de 22.451 pupas/L de dieta), foi mais eficiente do que a FM (6.688 pupas/kg de dieta). Quanto à viabilidade econômica, a dieta larval MC foi mais vantajosa, demandando um investimento médio de R$ 312,67 para a produção de 1 milhão de pupas, enquanto que a dieta FM custou R$ 1.266,36 para produzir a mesma quantidade de pupas / Several species of fruit flies have been the subject of research for their mass rearing, including Ceratitis capitata (Wiedemann) (Mediterranean fruit fly or medfly) and, more recently, Anastrepha fraterculus (Wiedemann) (South American fruit fly), being these species the ones with most economic and quarantine importance in several fruit producing areas of Brazil, Uruguay, Argentina and Peru. One of the requirements for the Sterile Insect Technique (SIT) is the existence of mass rearing methods of the target species. In order to achieve the large-scale rearing of these species of fruit flies, it is necessary initially to develop a suitable larval diet. As the rearing diet can offer a huge amount of nutrients, artificially reared larvae mature earlier than wild ones, what accelerates the succession of generations. These changes during the larval stage may form adults with higher nutritional reserves and they can reach sexual maturity earlier. There are several mass-rearing facilities for fruit flies in the world capable of producing sterile males that are used for population eradication and suppression in area-wide. In order to reduce insect production costs, the optimization or development of new diets cannot stop. Therefore, the objectives of this study were to determine the adequacy and optimal larval density of C. capitata and A. fraterculus flies in new diets based on corn flour (FM), sugarcane bagasse (BC), lyophilized carrot powder (PC) and carrageenan (MC), choosing the most efficient and less costly diet for the production of each of the species, based on the quantity and quality of insects reared and production costs. The optimal larval densities for C. capitata in larval diets FM, BC and PC were, respectively, 0.5; 2.0 and 1.0 mL of eggs/kg of diet. The larval diet that reached the highest productivity was the BC diet, giving an average of 6,514 pupae/ kg of diet, followed by FM and PC diets, which produced an average of 5,018 and 4,115 pupae per kg of diet, respectively. The decreasing order of economic viability among the three larval diets used was the same (BC>FM>PC), requiring a mean investment of R$ 471.29; R$ 482.26; and R$ 1,085.85, respectively, for the production of 1 million pupae. The results with A. fraterculus showed that the ideal larval densities in FM and MC diets were 2.0 eggs/kg of diet and 1.5 mL of eggs/L of diet, respectively. The PC larval diet was considered infeasible based on the low production and weight of pupae. In terms of productivity, the MC larval diet, which resulted in an average of 22,451 pupae produced per L of diet, was more efficient than FM, which produced a mean of 6,688 pupae per kg of diet. Considering the economic costs, the MC larval diet was also superior, requiring R$ 312,67.00 for the production of 1 million pupae, while the FM diet required R$ 1,266.36 to produce the same amount of pupae

Wenn die Nutzer Erfahrungen mit Sozialen Netzwerken sammeln: i) tauschen sie Informationen mit einander aus; ii) verbinden sich mit einander und bilden Netzwerke; und iii) können auf soziales Kapital zugreifen, das durch die Pflege von diesen Kontakten entsteht. Die Struktur dieser Dissertation spiegelt diese drei Besonderheiten wider. In dem ersten Kapitel untersuchen wir den Einfluss von Informationseigenschaften – den Umfang, die Tiefe, den Kontext als auch dem Feedback – auf den Informationsnutzen. Im zweiten Kapitel untersuchen wir die Netzwerk-Gestaltungsstrategien und die Beziehung von den resultierenden Netzwerkeigenschaften – die Beziehungsstärke als auch Netzwerküberschneidung – mit dem Informationsnutzen. Im dritten Kapitel erforschen wir den Einfluß von den gewonnenen Informationen und der Struktur des Netzwerkes – auf das Soziale Kapital. Zusätzlich beziehen wir in jedes Kapitel die Erfahrung der Nutzer mit dem Medium ein. Aufgrund von fehlenden Forschungserkenntnissen, setzen wir Grounded Theory ein, um konzeptionelle Verhaltensmodelle zu entwickeln. Diese Modelle werden im Anschluß empirisch getestet. Obwohl die Forschung in dieser Dissertation meist verhaltenswissenschaftlich ist, kann man auch Ansätze aus der Design Science erkennen. Zum Beispiel, spezielle Facebook-Anwendungen sind implementiert um reale Nutzerdaten zeitnah zu sammeln. Diese Dissertation weisst drei Hauptergebnisse auf. Erstens, die Beziehungsstärke ist der wichtigster Faktor, der das Verhalten von den Nuztern bestimmt. Zweitens, obwohl die Nutzer die Informationen von Ihren engen Freunden bevorzugen, andere Netzwerkeigenschaften sollten in Betracht gezogen werden, denn zum Beispiel Netzwerküberschneidung einen negativen Einfluss auf Informationsnutzen hat. Drittens, Erfahrungsfaktoren beinflussen das Nutzerverhalten auf diesen Netzwerken. / As SNS users gain experience with using SNS they: i) exchange the information with each other; ii) connect with each other and form certain network structures as a result; iii) obtain the social capital benefits due to the maintenance of relationships with others. The dissertation structure clearly reflects these peculiarities of SNS. Thus, in the first part of the dissertation we explore the impact of information characteristics – depth, breadth, context, social information – on the value of information users derive from their networks. In the second part of the dissertation we explore how users construct their networks and how properties of network structure – tie strength and network overlap – relate to information value. In the third part, we explore the impact of network structure and shared information in the process of social capital formation. We additionally control for the user experience, as we believe that this factor might impact the perception of value. Due to the scarcity of research findings we use explorative methodologies, such as Grounded Theory to study these new phenomena and generate conceptual models. These models are then verified empirically. Although most of the research presented in this dissertation is behavioral, we can also recognize design science elements. For example, we design and implement Facebook applications that allow to collect user data in real time. The main results of the dissertation can be summarized around three major contributions. First and foremost, the underlying tie strength emerges as the most important factor that drivers user behavior on SNS. Second, although people prefer information from their stronger ties, researchers should differentiate between different forms of network structure in their impact on information value, as, for example, network overlap has a negative relationship with information value. Third, experience factors mediate many of the behaviors of users on SNS.