Uppsatsen ämnar belysa hur Harry Martinsons Aniara (1956) förebådar postmodernismen trots att verket är rotat i den modernistiska traditionen. Analysen tar upp två aspekter med fokus på innehåll och berättarteknik där verket visar prov på en postmodern idévärld. Först behandlas miman, och resonemang förs kring att hon och hennes produktion bör ses som en masskulturell företeelse snarare än som elitistisk diktkonst. Analysen anknyter till Baudrillards teori om hyperverklighet och simulacrum och visar på hur miman skapar detta med sin kultur­produktion. Här framstår två tolkningsalternativ: ett där miman i egenskap av masskultur upp­värderar synen på masskulturen och pekar framåt mot postmodernismen, och ett andra där hon blir en negativ symbol för masskulturen. Detta eftersom hon döljer verkligheten för befolkningen så pass länge att de slutar försöka lösa sin situation. Den andra aspekten är Aniaras förhållande till metanarrativ, vilket belyses utifrån Lyotards teorier om vad som kännetecknar det postmoderna samhället. Analysen visar hur metanarrativen ses som omöjliga inom fiktionen och istället byts ut mot lokalt meningsskapande. Verket i sin helhet bjuder också på motstånd mot metanarrativ genom att (1) utge sig för att vara en klart av­gränsad händelse, (2) skriva ut ett motstånd mot djuplodande tolkningar och slutligen genom att (3) mimaroben som ska förmedla revyn över människan i tid och rum inte är pålitlig nog att lägga fram en allmän sanning. Sammantaget konstateras att verket är rotat i modernismen men att det samtidigt förebådar postmodernismen i dess syn på masskultur, hyperverklighet och meta­narrativ. / The aim of this essay is to highlight tendencies of postmodernism in Harry Martinson’s Aniara (1956), a work that has traditionally been placed in a modernist context. The analysis centers around two aspects in the text with the aim of finding traces of a postmodern world view. First the “mima”, an enigmatic machine that consoles the passengers in the first six years of the journey, is reasoned to be a mass cultural phenomenon rather than an elitist poetic device, as pre­vious studies have suggested. The cultural production of the machine is then analyzed in the light of the theories of hyper reality and simulacrum, as conceived by Jean Baudrillard. The analysis renders two possible implications, one where the machine can be viewed as a precursor to a post­modern positive attitude of mass culture, and one more modernistic where the machine in its role as mass culture numbs the passengers and prevents them from acting on their situation in time. The second part of the analysis focuses on the view of metanarratives, as expressed within the fiction and in the wok as a whole. Jean-François Lyotard and his explanation of postmodernism’s incredulity towards metanarratives is used as a theoretical standpoint. The analysis shows that metanarratives are considered impossible within the fiction of Aniara as during the course of the journey, they are replaced with more local methods of creating meaning. On the whole, the book could be seen to replace the metanarrative of human progress by one telling of the inadequacy and inert destructibility of humanity. However, the analysis shows that metanarratives are rejected all together. The construction of a new metanarrative is made impossible by (1) the fictitious accounts clearly being a local event, (2) the text openly stating the impossibility of deeper interpretation and finally (3) the work employing a narrator too unreliable to be able to convey the unarguable truths necessary to create a new metanarrative.

Introduction : Chez les nouveau-nés prématurés, l’hyper-alimentation intraveineuse (HAIV) contribue à leur survie, mais elle est aussi une source importante de molécules oxydantes. L’absence d’une protection adéquate contre la lumière ambiante génère in vitro, via la photo-excitation de la riboflavine, du H2O2, des peroxydes organiques et un dérivé peroxydé de la vitamine C, l’ascorbylperoxyde (AscOOH). Plusieurs données du laboratoire associent l’infusion d’HAIV à des désordres lipidiques dans notre modèle animal. L’hypothèse est donc que l’AscOOH a un pouvoir oxydant et est responsable de certains des effets biologiques observés. Mes objectifs sont les suivants : 1) développer une méthode de dosage de l’AscOOH; 2) démontrer, à l’aide du modèle animal bien établi au laboratoire, des relations entre la concentration tissulaire de cette molécule et des paramètres métaboliques et l’état redox au foie et dans la circulation; et 3) confirmer l’effet physiologique de l’AscOOH dans un modèle cellulaire. Méthode : Différents étalons internes potentiels ont été testés pour le dosage de l’AscOOH par spectrométrie de masse après séparation sur HPLC (LC-MS). Les phases mobiles et conditions chromatographiques ont été optimisées. Pour l’objectif 2, des cobayes de 3 jours de vie (n=11) ont reçu par voie intraveineuse une dose d’AscOOH (entre 0 et 3,3mM). Les animaux ont été sacrifiés au 4e jour de traitement pour le prélèvement de tissus. Les concentrations tissulaires d’AscOOH ont été déterminées au LC-MS. La triglycéridémie et la cholestérolémie ont été mesurées à l’aide d’un kit commercial par spectrophotométrie. Le glutathion oxydé et réduit ont été mesurés par électrophorèse capillaire. Les relations linéaires obtenues sont exprimées par le ratio des carrés (r2), et traitées par ANOVA. Résultats : La validation du dosage de l’AscOOH par LC-MS a été réalisée. Chez les animaux, la concentration urinaire d’AscOOH par créatinine corrèle positivement avec la dose reçue, négativement avec la lipidémie, et négativement avec le redox sanguin et érythrocytaire, indiquant un milieu moins oxydé. Conclusion : La concentration urinaire d’AscOOH peut donc être un reflet de l’oxydation de l’HAIV en clinique. Nos données chez l’animal suggèrent une interaction de l’AscOOH avec le métabolisme hépatique produisant une chute de la concentration plasmatique de cholestérol et de triglycérides. Le modèle cellulaire n’a pas permis d’élucider le mécanisme moléculaire de l’action de l’AscOOH sur le métabolisme. / Introduction: Intravenous hyperalimentation (IVHA) often contributes to the survival of preterm newborns, but it is also an important source of oxidizing molecules. The lack of adequate protection from ambient light generates, in vitro, through the photo-excitation of riboflavin, H2O2, organic peroxides and a peroxidated derivative of vitamin C: ascorbylperoxide (AscOOH). Certain data from our laboratory linked the infusion of IVHA to lipid disorders in our animal model. The hypothesis is that AscOOH is an oxidant that is responsible for some of the biological effects observed. My objectives are: 1) to develop a method for quantitation of AscOOH, 2) to demonstrate, using the guinea pig model used by our laboratory, relations between the tissue concentration of this molecule and metabolic and redox parameters in the liver and plasma, and 3) to confirm the physiological effect of AscOOH in a cell culture model. Method: Different promising internal standards were tested for AscOOH quantitation by mass spectrometry after HPLC separation (LC-MS). Mobile phases and chromatography conditions have been optimized. For objective #2, 3 days old guinea pig pups (n = 11) received an intravenous dose of AscOOH (between 0 and 3.3mM). Animals were sacrificed on the 4th day of treatment for tissue gathering. Tissues AscOOH concentrations were determined by LC-MS. The triglyceride and cholesterol levels were measured by spectrophotometry using a commercial kit. The oxidized and reduced glutathione were measured by capillary electrophoresis. The linear relations obtained are expressed by the square of the correlation coefficient (r2), and processed by ANOVA. Results: The validation of the LC-MS method for AscOOH quantification has been achieved. In animals, the concentration of urinary AscOOH by creatinine correlates positively with the dose received, negatively with blood lipids, and negatively with blood and erythrocyte redox, indicating a less oxidized environment. Conclusion: The urinary AscOOH concentration may be a good indicator of the oxidation state of clinical IVHA. Our data in animals suggest an interaction between AscOOH and liver metabolism producing a drop in plasma concentration of cholesterol and triglycerides. The cell model was not able to clarify the molecular mechanism of AscOOH action on metabolism.

Dans le domaine des neurosciences computationnelles, l'hypothèse a été émise que le système visuel, depuis la rétine et jusqu'au cortex visuel primaire au moins, ajuste continuellement un modèle probabiliste avec des variables latentes, à son flux de perceptions. Ni le modèle exact, ni la méthode exacte utilisée pour l'ajustement ne sont connus, mais les algorithmes existants qui permettent l'ajustement de tels modèles ont besoin de faire une estimation conditionnelle des variables latentes. Cela nous peut nous aider à comprendre pourquoi le système visuel pourrait ajuster un tel modèle; si le modèle est approprié, ces estimé conditionnels peuvent aussi former une excellente représentation, qui permettent d'analyser le contenu sémantique des images perçues. Le travail présenté ici utilise la performance en classification d'images (discrimination entre des types d'objets communs) comme base pour comparer des modèles du système visuel, et des algorithmes pour ajuster ces modèles (vus comme des densités de probabilité) à des images. Cette thèse (a) montre que des modèles basés sur les cellules complexes de l'aire visuelle V1 généralisent mieux à partir d'exemples d'entraînement étiquetés que les réseaux de neurones conventionnels, dont les unités cachées sont plus semblables aux cellules simples de V1; (b) présente une nouvelle interprétation des modèles du système visuels basés sur des cellules complexes, comme distributions de probabilités, ainsi que de nouveaux algorithmes pour les ajuster à des données; et (c) montre que ces modèles forment des représentations qui sont meilleures pour la classification d'images, après avoir été entraînés comme des modèles de probabilités. Deux innovations techniques additionnelles, qui ont rendu ce travail possible, sont également décrites : un algorithme de recherche aléatoire pour sélectionner des hyper-paramètres, et un compilateur pour des expressions mathématiques matricielles, qui peut optimiser ces expressions pour processeur central (CPU) et graphique (GPU). / Computational neuroscientists have hypothesized that the visual system from the retina to at least primary visual cortex is continuously fitting a latent variable probability model to its stream of perceptions. It is not known exactly which probability model, nor exactly how the fitting takes place, but known algorithms for fitting such models require conditional estimates of the latent variables. This gives us a strong hint as to why the visual system might be fitting such a model; in the right kind of model those conditional estimates can also serve as excellent features for analyzing the semantic content of images perceived. The work presented here uses image classification performance (accurate discrimination between common classes of objects) as a basis for comparing visual system models, and algorithms for fitting those models as probability densities to images. This dissertation (a) finds that models based on visual area V1's complex cells generalize better from labeled training examples than conventional neural networks whose hidden units are more like V1's simple cells, (b) presents novel interpretations for complex-cell-based visual system models as probability distributions and novel algorithms for fitting them to data, and (c) demonstrates that these models form better features for image classification after they are first trained as probability models. Visual system models based on complex cells achieve some of the best results to date on the CIFAR-10 image classification benchmark, and samples from their probability distributions indicate that they have learnt to capture important aspects of natural images. Two auxiliary technical innovations that made this work possible are also described: a random search algorithm for selecting hyper-parameters, and an optimizing compiler for matrix-valued mathematical expressions which can target both CPU and GPU devices.

Les explosifs sont des matériaux qui, bien que potentiellement sensibles, sont conçus pour être stables en conditions normales, ainsi que lors de sollicitations mécaniques, chimiques ou thermiques " faibles ". Pourtant, sous sollicitations mécaniques de faible intensité, comme les impacts basse vitesse, ils peuvent réagir de manière intempestive. Les propergols, et plus particulièrement la butalite, objet de notre étude, présentent ce caractère : on observe des " réactions " pour des vitesses d'impacts inférieures à 100 m.s-1, dont l'origine est probablement liée à l'endommagement microstructural du matériau. Dans ce contexte, le but ultime du CEA Gramat est d'obtenir un outil de prédiction de la vulnérabilité des matériaux énergétiques pour les impacts à basse vitesse de type " tour de chute ". Pour ce faire, il est essentiel de disposer de données sur la morphologie et le comportement (thermo)mécanique macroscopique du matériau considéré, de ses phases constitutives à l'échelle mésoscopique et de ses interfaces. Ainsi l'objectif de la thèse est de déterminer le type et le niveau de(s) endommagement(s) apparaissant(s) dans une " butalite inerte " suite à un impact mécanique dit " à basse vitesse " (i.e., inférieure à 100 m.s-1) réalisé à l'aide d'un dispositif de type tour de chute modifié, associant un suivi par vidéo numérique rapide et une analyse microtomographique ante- et post-essai, en étudiant le ou les phénomènes physiques à l'origine des réactions sous " faibles " sollicitations, leur évolution et leur(s) origine(s) physique(s). Les grains sont modélisés par une loi de comportement purement élastique et la matrice en PBHT est décrite par une loi visco-hyper-élastique (couplage d'une série de Prony et du modèle de Mooney-Rivlin).

L'imagerie acoustique est une technique performante pour la localisation et la reconstruction de puissance des sources acoustiques en utilisant des mesures limitées au réseau des microphones. Elle est largement utilisée pour évaluer l'influence acoustique dans l'industrie automobile et aéronautique. Les méthodes d'imagerie acoustique impliquent souvent un modèle direct de propagation acoustique et l'inversion de ce modèle direct. Cependant, cette inversion provoque généralement un problème inverse mal-posé. Par conséquent, les méthodes classiques ne permettent d'obtenir de manière satisfaisante ni une haute résolution spatiale, ni une dynamique large de la puissance acoustique. Dans cette thèse, nous avons tout d'abord nous avons créé un modèle direct discret de la puissance acoustique qui devient alors à la fois linéaire et déterminé pour les puissances acoustiques. Et nous ajoutons les erreurs de mesures que nous décomposons en trois parties : le bruit de fond du réseau de capteurs, l'incertitude du modèle causée par les propagations à multi-trajets et les erreurs d'approximation de la modélisation. Pour la résolution du problème inverse, nous avons tout d'abord proposé une approche d'hyper-résolution en utilisant une contrainte de parcimonie, de sorte que nous pouvons obtenir une plus haute résolution spatiale robuste à aux erreurs de mesures à condition que le paramètre de parcimonie soit estimé attentivement. Ensuite, afin d'obtenir une dynamique large et une plus forte robustesse aux bruits, nous avons proposé une approche basée sur une inférence bayésienne avec un a priori parcimonieux. Toutes les variables et paramètres inconnus peuvent être estimées par l'estimation du maximum a posteriori conjoint (JMAP). Toutefois, le JMAP souffrant d'une optimisation non-quadratique d'importants coûts de calcul, nous avons cherché des solutions d'accélération algorithmique: une approximation du modèle direct en utilisant une convolution 2D avec un noyau invariant. Grâce à ce modèle, nos approches peuvent être parallélisées sur des Graphics Processing Unit (GPU) . Par ailleurs, nous avons affiné notre modèle statistique sur 2 aspects : prise en compte de la non stationarité spatiale des erreurs de mesures et la définition d'une loi a priori pour les puissances renforçant la parcimonie en loi de Students-t. Enfin, nous ont poussé à mettre en place une Approximation Variationnelle Bayésienne (VBA). Cette approche permet non seulement d'obtenir toutes les estimations des inconnues, mais aussi de fournir des intervalles de confiance grâce aux paramètres cachés utilisés par les lois de Students-t. Pour conclure, nos approches ont été comparées avec des méthodes de l'état-de-l'art sur des données simulées, réelles (provenant d'essais en soufflerie chez Renault S2A) et hybrides.

Ozone, being an unstable molecule, is believed to be one of the strongest oxidant agents known to man. Rapid growth in the application of ozone — both as disinfectant and as form of alternative medicine — led to questions about the effects of uncontrolled ozone exposure and inhalation, whether intentional or unintentional, on the human body. This study specifically focussed on examining, identifying and substantiating the respiratory effect of acute exposure (10 min or less) to considerably higher ozone concentrations than reported on before (19.5 ± 0.5 ppm). Respiratory tissue of rodents (Duncan–Hartley guinea pigs of both sexes and Male Wistar rats) was subjected to ozone by utilising three distinctly diverse models of ozone introduction: (a) in vitro exposure, (b) in vivo exposure, and (c) ex vivo by employing an isolated lung perfusion model which allows for real–time, breath–by–breath data acquisition of ozone’s effect on respiratory mechanics. The effect of ozone on the isolated trachea in the presence of various drugs with well–known effects, including methacholine, isoproterenol and ascorbic acid was also examined. The results found in this study identified two direct effects on the isolated trachea due to ozone exposure: (1) a definite contraction of the isolated trachea immediately after exposure to ozone, and (2) a clearly visible and significant hyper responsiveness of the isolated trachea to irritants, e.g. methacholine. Although ozone has a negative effect on the trachea, it was concluded that ozone has no adverse effect on muscarinic acetylcholine receptors. An apparent EC50 value of ozone on the trachea was established by two different methods as (2.77 ± 0.02) x 10–3 M and (2.10 ± 0.03) x 10–3 M, respectively. Ozone furthermore displayed an attenuation of the beneficial pharmacological response of –sympathomimetic drugs (i.e. isoproterenol), while isoproterenol itself has a relaxing effect on the ozone–induced contraction of the isolated trachea. Indomethacin pre–treatment of isolated tracheal tissue significantly (77%) reduced the ozone–induced contraction of tracheal smooth muscle, suggesting that COXproducts of arachidonic acid play a prominent role in the development of pulmonary function decrements consequent to acute high–dose ozone exposure. Ascorbic acid exhibited a meaningful prophylactic effect on ozone–induced contraction of both isolated tracheal tissue and in the isolated lung perfusion model, emphasising the major role antioxidants play in both the epithelium lining fluid (ELF) of the respiratory system and in plasma throughout the body in protecting against the destructive effects of ozone. Surprisingly, pre–treatment with ascorbic acid did not prevent hyper responsiveness of isolated tracheal preparations to methacholine after a 10 min ozone (19.5 ± 0.5 ppm) exposure. In the lung perfusion model, the presence of ascorbic acid in the perfusion medium did, however, significantly reduce the magnitude and rate of decline in lung compliance after ozone exposure (46% decline with ascorbic acid versus 96% in the control study without ascorbic acid). Examination of a lung perfusion model exposed to ozone (19.5 ± 0.5 ppm O3; 5 seconds) presented a significant decline in lung compliance (95.6% within 2 min), tidal volume (70%) and maximum inspiratory flow (71.2%), with an ensuing reduction in lung elasticity and severely hampered breathing pattern. Microscopic examination after acute high–dose inhalation studies did not display any significant cellular damage, oedema or inflammation after acute high–dose ozone exposure. This suggests that significant cellular injury and inflammation is possibly not the causative factor of early breathing difficulty experienced after acute high–dose ozone inhalation, as these symptoms and particularly the result of inflammatory precursors, is believed to probably only set in at a later stage. Although the potential advantages of ozone in certain fields of medicine are not disputed, ozone, depending on its concentration and cumulative dose, can be either therapeutic or toxic. Observations in this study emphasised that even short bursts of high–dose ozone inhalation have deleterious effects on respiratory health and care should be taken not to jump to conclusions regarding ozone’s medical application without relevant scientific evidence. It must be stressed that high–dose inhalation of ozone should be avoided at all cost – especially by those with existing airway diseases. / Thesis (Ph.D. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

La présente thèse propose de situer et d’analyser les potentialités totalitaires participant de la réalité contemporaine. Pour ce, notre démarche se déploie en deux temps. Dans un premier temps, nous retraçons l’évolution philosophique du vivre-ensemble pour ainsi établir les principes et les origines d’un monde non-totalitaire. Dans un deuxième temps, nous nous penchons sur les conditions assurant à la fois la destruction du vivre-ensemble et l’essor des potentialités totalitaires. En mettant les deux composantes de notre démarche en rapport l’une avec l’autre, nous arrivons à une meilleure compréhension du processus par lequel le totalitarisme passe de son principe virtuel à sa réalisation effective en régime politique. La première partie de ce travail s’appuie sur les écrits de Hannah Arendt, de Herbert Marcuse et d’Aristote et s’intéresse surtout à l’œuvre et la responsabilité, à la misère privée et au bonheur public. La deuxième partie élabore la notion de la chrématistique dans la pensée d’Aristote et développe son mode de vie correspondant appelé hyper-responsabilité en invoquant Malcolm Gladwell, Georg Lukàcs, Thomas Hobbes, Léo Strauss et Hannah Arendt.

Ozone, being an unstable molecule, is believed to be one of the strongest oxidant agents known to man. Rapid growth in the application of ozone — both as disinfectant and as form of alternative medicine — led to questions about the effects of uncontrolled ozone exposure and inhalation, whether intentional or unintentional, on the human body. This study specifically focussed on examining, identifying and substantiating the respiratory effect of acute exposure (10 min or less) to considerably higher ozone concentrations than reported on before (19.5 ± 0.5 ppm). Respiratory tissue of rodents (Duncan–Hartley guinea pigs of both sexes and Male Wistar rats) was subjected to ozone by utilising three distinctly diverse models of ozone introduction: (a) in vitro exposure, (b) in vivo exposure, and (c) ex vivo by employing an isolated lung perfusion model which allows for real–time, breath–by–breath data acquisition of ozone’s effect on respiratory mechanics. The effect of ozone on the isolated trachea in the presence of various drugs with well–known effects, including methacholine, isoproterenol and ascorbic acid was also examined. The results found in this study identified two direct effects on the isolated trachea due to ozone exposure: (1) a definite contraction of the isolated trachea immediately after exposure to ozone, and (2) a clearly visible and significant hyper responsiveness of the isolated trachea to irritants, e.g. methacholine. Although ozone has a negative effect on the trachea, it was concluded that ozone has no adverse effect on muscarinic acetylcholine receptors. An apparent EC50 value of ozone on the trachea was established by two different methods as (2.77 ± 0.02) x 10–3 M and (2.10 ± 0.03) x 10–3 M, respectively. Ozone furthermore displayed an attenuation of the beneficial pharmacological response of –sympathomimetic drugs (i.e. isoproterenol), while isoproterenol itself has a relaxing effect on the ozone–induced contraction of the isolated trachea. Indomethacin pre–treatment of isolated tracheal tissue significantly (77%) reduced the ozone–induced contraction of tracheal smooth muscle, suggesting that COXproducts of arachidonic acid play a prominent role in the development of pulmonary function decrements consequent to acute high–dose ozone exposure. Ascorbic acid exhibited a meaningful prophylactic effect on ozone–induced contraction of both isolated tracheal tissue and in the isolated lung perfusion model, emphasising the major role antioxidants play in both the epithelium lining fluid (ELF) of the respiratory system and in plasma throughout the body in protecting against the destructive effects of ozone. Surprisingly, pre–treatment with ascorbic acid did not prevent hyper responsiveness of isolated tracheal preparations to methacholine after a 10 min ozone (19.5 ± 0.5 ppm) exposure. In the lung perfusion model, the presence of ascorbic acid in the perfusion medium did, however, significantly reduce the magnitude and rate of decline in lung compliance after ozone exposure (46% decline with ascorbic acid versus 96% in the control study without ascorbic acid). Examination of a lung perfusion model exposed to ozone (19.5 ± 0.5 ppm O3; 5 seconds) presented a significant decline in lung compliance (95.6% within 2 min), tidal volume (70%) and maximum inspiratory flow (71.2%), with an ensuing reduction in lung elasticity and severely hampered breathing pattern. Microscopic examination after acute high–dose inhalation studies did not display any significant cellular damage, oedema or inflammation after acute high–dose ozone exposure. This suggests that significant cellular injury and inflammation is possibly not the causative factor of early breathing difficulty experienced after acute high–dose ozone inhalation, as these symptoms and particularly the result of inflammatory precursors, is believed to probably only set in at a later stage. Although the potential advantages of ozone in certain fields of medicine are not disputed, ozone, depending on its concentration and cumulative dose, can be either therapeutic or toxic. Observations in this study emphasised that even short bursts of high–dose ozone inhalation have deleterious effects on respiratory health and care should be taken not to jump to conclusions regarding ozone’s medical application without relevant scientific evidence. It must be stressed that high–dose inhalation of ozone should be avoided at all cost – especially by those with existing airway diseases. / Thesis (Ph.D. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

An interpretative methodology for understanding meaning in cinema since the 1950s, auteur analysis is an approach to film studies in which an individual, usually the director, is studied as the author of her or his films. The principal argument of this thesis is that proponents of auteurism have privileged examination of the visual components in a film-maker’s body of work, neglecting the potentially significant role played by sound. The thesis seeks to address this problematic imbalance by interrogating the creative use of sound in the films written and directed by Rolf de Heer, asking the question, “Does his use of sound make Rolf de Heer an aural auteur?” In so far as the term ‘aural’ encompasses everything in the film that is heard by the audience, the analysis seeks to discover if de Heer has, as Peter Wollen suggests of the auteur and her or his directing of the visual components (1968, 1972 and 1998), unconsciously left a detectable aural signature on his films. The thesis delivers an innovative outcome by demonstrating that auteur analysis that goes beyond the mise-en-scène (i.e. visuals) is productive and worthwhile as an interpretive response to film. De Heer’s use of the aural point of view and binaural sound recording, his interest in providing a ‘voice’ for marginalised people, his self-penned song lyrics, his close and early collaboration with composer Graham Tardif and sound designer Jim Currie, his ‘hands-on’ approach to sound recording and sound editing and his predilection for making films about sound are all shown to be examples of de Heer’s aural auteurism. As well as the three published (or accepted for publication) interviews with de Heer, Tardif and Currie, the dissertation consists of seven papers refereed and published (or accepted for publication) in journals and international conference proceedings, a literature review and a unifying essay. The papers presented are close textual analyses of de Heer’s films which, when considered as a whole, support the thesis’ overall argument and serve as a comprehensive auteur analysis, the first such sustained study of his work, and the first with an emphasis on the aural.

Apesar de sua inerente indecidibilidade e do problema da negação, extensões da lógica de primeira ordem tem se mostrado capazes de superar a questão da monotonicidade, vindo a constituir esquemas de representação de conhecimento de expressividade virtualmente universal. Resta entretanto solucionar ou pelo menos amenizar as conseqüências do problema do controle, que limitam o seu emprego a aplicações de pequeno a médio porte. Investigações nesse sentido [BOW 85] [MON 88] indicam que a chave para superar a explosão inferencial passa obrigatoriamente pela estruturação do conhecimento, de modo a permitir o exercício de algum controle sobre as possíveis derivações dele decorrentes. O modelo das hiperredes [GEO 85] parece atingir tal objetivo, dado o seu elevado potencial de estruturação e o instrumental que oferece para o tratamento de construções descritivas, operacionais e organizacionais. Além disso, a simplicidade e uniformidade sintática de suas entidades primitivas possibilita uma interpretação semântica bastante clara do modelo original, por exemplo, baseada em grafos. O presente trabalho representa uma tentativa de associar a programação em lógica ao formalismo das hiperredes, visando obter um novo modelo capaz de preservar as expressividade da primeira, beneficiando-se simultaneamente do potencial heurístico e estrutura do segundo. Inicialmente procura-se obter uma noção clara da natureza do conhecimento e de seus mecanismos com o objetivo de caracterizar o problema da representação de conhecimento. Diferentes esquemas correntemente empregados para esse fim (sistemas de produções, redes semânticas, sistemas de frames, programação em lógica e a linguagem Krypton) são estudados e caracterizados do ponto de vista de sua expressividade, potencial heurístico e conveniência notacional. A programação em lógica é objeto de um estudo em maior profundidade, sob os enfoques modelo-teorético e prova-teorético. Sistemas de programação em lógica - particularmente a linguagem Prolog e extensões em nível meta - são investigados como esquemas de representação de conhecimento, considerando seus aspectos sintáticos e semânticos e a sua retação com Sistemas Gerenciadores de Bases de Dados. O modelo das hiperredes é apresentado introduzindo-se, entre outros, os conceitos de hipernodo, hiperrelação e protótipo, assim como as propriedades particutares de tais entidades. A linguagem Hyper, para o tratamento de hiperredes, é formalmente especificada. Emprega-se a linguagem Prolog como formalismo para a representação de Bases de Conhecimento estruturadas segundo o modelo das hiperredes. Sob tal abordagem uma Base de Conhecimento é vista como um conjunto (possivelmente vazio) de objetos estruturados ou peças de conhecimento, que por sua vez são classificados como hipernodos, hiperrelações ou protótipos. Um mecanismo top-down para a produção de inferências em hiperredes é proposto, introduzindo-se os conceitos de aspecto e visão sobre hiperredes, os quais são tomados como objetos de primeira classe, no sentido de poderem ser valores atribuídos a variáveis. Estuda-se os requisitos que um Sistema Gerenciador de Bases de Conhecimento deve apresentar, do ponto de vista da aplicação, da engenharia de conhecimento e da implementação, para suportar efetivamente os conceitos e abstrações (classificação, generalização, associação e agregação) associadas ao modelo proposto. Com base nas conclusões assim obtidas, um Sistema Gerenciador de Bases de Conhecimento (denominado Rhesus em alusão à sua finalidade experimental é proposto e especificado, objetivando confirmar a viabilidade técnica do desenvolvimento de aplicações baseadas em lógica e hiperredes. / In spite of its inherent undecidability and the negation problem, extensions of first-order logic have been shown to be able to overcome the question of the monotonicity, establishing knowledge representation schemata with virtuatLy universal expressiviness. However, one still has to solve, or at Least to reduce the consequences of the control problem, which constrains the use of Logic-based systems to either small or medium-sized applications. Investigations in this direction [BOW 85] [MON 88] indicate that the key to overcome the inferential explosion resides in the proper knowledge structure representation, in order to have some control over possible derivations. The Hypernets Model [GEO 85] seems to reach such goat, considering its high structural power and the features that it offers to deal with descriptive, operational and organizational knowledge. Besides, the simplicity and syntactical uniformity of its primitive notions allows a very clear definition for its semantics, based, for instance, on graphs. This work is an attempt to associate logic programming with the hypernets formalism, in order to get a new model, preserving the expressiveness of the former and the heuristic and structural power of the latter. First we try to get a clear notion of the nature of knowledge and its main aspects, intending to characterize the knowledge representation problem. Some knowledge representation schemata (production systems, semantic networks, frame systems, Logic programming and the Krypton Language) are studied and characterized from the point of view of their expressiveness, heuristic power and notational convenience. Logic programming is the subject of a deeper study, under the model-theoretic and proof-theoretic approaches. Logic programming systems - in particular the Prolog Language and metateuel extensions- - are investigated as knowledge representation schemata, considering its syntactic and semantic aspects and its relations with Data Base Management Systems. The hypernets model is presented, introducing the concepts of hypernode, hyperrelation and prototype, as well as the particular properties of those entities. The Hyper language, for the handling of h y pernets, is formally specified. Prolog is used as a formalism for the representation of Knowledge Bases which are structured as hypernets. Under this approach a Knowledge Brie is seen rrG a (possibly empty) set of structured objects, which are classified as hypernodes, hyperreLations or prototypes. A mechanism for top-down reasoning on hypernets is proposed, introducing the concepts of aspect and vision, which are taken as first-class objects in the sense that they could be (-Ysigned as values to variables. We study the requirements for the construction of a Knowledge Base Management System from the point of view of the user's need-1', knowledge engineering support and implementation issues, actually supporting the concepts and abstractions (classification, generalization, association and aggregation) rYsociated with the proposed model. Based on the conclusions of this study, a Knowledge Base Management System (called Rhesus, refering to its experimental objectives) is proposed, intending to confirm the technical viability of the development of applications based on logic and hypernets.