Abstract The objective of this thesis was to determine the effects of design, operational and furnish quality parameters on pressure screen and hydrocyclone performance. The general contradictory interrelationships between capacity and selectivity in pressure screening and cleaning are commonly recognized, but deep understanding of the effects of design, operational and furnish quality parameters on the state of operation is missing. As separation selectivity is closely dependent on thickening and pulp passage, an operation curve for separation was applied and its application further developed to examine the parameters affecting pressure screen and hydrocyclone separation. New information was found on the geometry of the screen plate, furnish quality parameters in pressure screen fibre fractionation, and the hydrocyclone separation of fibres, sand and gases. The capacity increases achieved by changes in the wire screen plate geometry were found to be achieved at the cost of separation selectivity in probability screening. The capacity of the screen plate was affected by the flow on the screen plate and through it. The hydraulic resistance both in the forward and reverse flow directions was found to be of great importance for the capacity of the screen plate. Previously unreported knowledge was found regarding the effects of wire width, height and shape. Pressure screening capacity was found to decrease with increasing fibre length, fibre network strength and flocculation. Pressure screen fibre fractionation selectivity was increased by broadening of the fibre length distribution of the feed furnish. The furnish properties also affected the separation selectivity of fibres, sand and gases in the hydrocyclone. An increase in fibre network strength reduced the separation selectivity of the hydrocyclone separation of fibres and sand. Any increase in the specific surface area, and especially in the amount of fines, was found to make gas removal more challenging. It was concluded that a broader range of the specific surface distribution can increase the selectivity of fibre fractionation in the hydrocyclone. Knowledge of the general effects of design, operational and furnish quality parameters on the performance of pressure screen and hydrocyclone separation was deepened as a result of this work, which provides a framework for studying these effects further in pursuit of the general objective of maximizing capacity and selectivity while minimizing energy and investment costs.

Pattern formation is the process by which undifferentiated cells divide and differentiate to generate complex tissues and organs. In plants, pattern formation begins in embryogenesis and continues post-embryonically with the function of the meristems. microRNAs (miRNAs), which are small regulatory RNAs that repress gene expression, are involved in a variety of patterning processes in plants, including the formation and function of the meristems and establishment of polarity. For example, regulation of the class III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors by miR165/6 is not only involved in the formation and function of the meristems, but also in polarity establishment in the leaf, and in axial patterning during embryogenesis. To gain a better understanding of the role of miRNAs in embryonic patterning, I investigated the tissue-specific functions of the miRNA biogenesis protein SERRATE (SE), which is required for the regulation of the HD-ZIP IIIs via miR165/6. By expressing SE in various domains in se-5 null mutant embryos, I revealed that although SE is expressed throughout the embryonic body, tissue-specific expression of SE from either the upper or lower tier of the embryo is sufficient for correct patterning. This observation suggests a SE-dependent non-cell autonomous and bi-directional mechanism that influences patterning in Arabidopsis embryos. Furthermore, through a suppressor screen of a se-3 loss-of-function mutant allele, I identified mutants in genes that likely function upstream of SE, and downstream or in parallel of the HD-ZIP IIIs. One of those se-3 suppressors is likely to be a mutant in the BELL homeobox gene POUND-FOOLISH (PNF).

The TRIUMF view screen system encompases a set of devices which individually image, and produce measurements of, the transverse profile of an accelerated electron beam. A control system is an essential component of the overall diagnostic device. The system requirements were compiled from those produced by the TRIUMF laboratory and from those based on the needs of the individual diagnostic devices. Based on the requirements, a control system was designed and implemented with a combination of industrial electrical and mechanical hardware, and a variety of software components. One component of the image reconstruction algorithm was validated with experimental data; the accuracy and precision of beam profile measurements was evaluated through simulation studies. Although it was not possible to demonstrate the satisfaction of requirements relating to alignment, it was shown that all other requirements were satisfied. / Graduate / 0798 / 0752 / 0605

Les attentats commis sur le sol américain le 11 septembre 2001 ont transi quasi simultanément une incommensurable communauté de regards. Cette participation scopique plurielle a très vite suscité des analogies avec le cinéma-catastrophe, immense pourvoyeur de fictions d’apocalypse urbaine, accusé d’avoir inspiré les commanditaires de l’attentat, d’avoir déréalisé toute catastrophe et de ne pas nous avoir préparé à son surgissement dans la réalité, ou désigné encore comme mètre-étalon de nos fantasmes apocalyptiques auxquels les images médiatiques ont dû se mesurer au point de déréaliser l’événement lui-même. Pour essayer de saisir les logiques de continuité ou de rupture auquel le cinéma américain se trouve exposé à la suite de cet événement, il importe de se demander dans quelles mesures le 11 septembre a pu entailler les habitudes du regard que le spectaculaire Hollywoodien nous avait intimement inculquées. Par comparaison avec le modèle figuratif des images médiatiques de l’attentat, Hollywood peut-il encore se permettre de mettre en scène le chaos au nom d’une pure invention figurative sans référent réel ? Après le 11/9, la représentation du désastre au cinéma n’est-elle pas en position d’incriminer le plaisir pris autrefois devant le spectacle fictionnel du chaos ? La culpabilité ne s’invite-t-elle pas dans le cœur même de la figuration du désastre, le souvenir dysphorique ne s'immisce-t-il pas dans la représentation urbaine, la reconstitution de l'événement ne déclare-t-elle pas ses limites face aux images médiatiques concurrentielles ? Après le 11 septembre, Hollywood semble se laisser déborder par une réalité insaisissable. / Throughout the world on September 11 2001, people watching their screens simultaneously suffered a deep shock caused by the attacks on the American soil. Given the variety of the viewers, parallels were at once made with Hollywood disaster-films which had always been huge providers of urban apocalyptic fiction. These films were charged with having inspired the perpetrators of the attacks, by naturalising disaster as such – so to speak – and thus leaving us unprepared for its intrusion into the real. In other words, Hollywood would have created a reference for our apocalyptic fears to the point that the media, by replicating such fictional images, thus deprived the tragic event itself of its reality. Because since then, American cinema cannot avoid dealing with narratives ruled by ruptures vs continuities which call for analysis, one needs to examine how deeply the 9/11 tragedy has altered the Hollywood spectator’ s gaze, i.e. one’s visual expectations and habits regarding spectacular attraction. Given the realistic images of the attacks in the media, can Hollywood still afford to show chaos on the screen as mere pleasurable fiction? After 9/11, has it become impossible for us to enjoy chaos on the screen without experiencing a feeling of guilt? How far do tragic memories interfere with any kind of urban representation? How does the cinematic reconstruction of the very event suffer from the essentially competitive nature of media images? After September 11, Hollywood appears unable to cope with a reality which remains forever elusive.

Introduction : La rétroaction sur la performance des personnes étudiantes infirmières lors de l’utilisation de simulateur de patients sur ordinateur contribuerait à l’apprentissage et au développement du raisonnement clinique en supportant la métacognition (Zary et al., 2006). Or à notre connaissance, la forme et le contenu de ce type de rétroaction demeure peu discuté dans les écrits scientifiques. Objectif : Ce projet de recherche comportait trois objectifs. Le premier était de contribuer au développement d’une fonctionnalité de rétroaction dans un simulateur sur écran, le second visait à documenter la perception de son utilité à la suite d’une expérimentation guidée en laboratoire auprès de personnes étudiantes infirmières et, enfin, le troisième objectif visait à décrire l’appréciation générale du simulateur par les personnes participantes. Méthodes : Un devis de recherche descriptif avec méthodes mixtes auprès d’un échantillon de convenance constitué d’étudiantes et étudiants en sciences infirmières d’une université québécoise a été retenu pour cette étude. Le modèle de rétroaction PROMPTED (Rudland et al., 2013) a été retenu pour orienter la conception de la rétroaction dans le simulateur sur écran. L’accès au simulateur s’est fait par un lien web et, par la suite, les personnes participantes devaient compléter un questionnaire web autoadministré pour documenter leur appréciation de la rétroaction fournie pendant la simulation et du simulateur sur écran en soi. De plus, des entrevues ont été réalisées pour enrichir la description de l’utilité perçue de la rétroaction offerte dans le simulateur sur écran. Résultats : La rétroaction intégrée dans le simulateur sur écran selon les principes du modèle PROMPTED a permis de guider et de bien renseigner les étudiantes au cours de l’activité. Les données recueillies suggèrent l’appréciation de l’utilisation de la rétroaction en cours d’activité plutôt que d’avoir seulement un solutionnaire à la fin de l’exercice. Conclusion : En plus d’apporter une plus-value au simulateur sur écran par rapport à ce qui se retrouve sur le marché, ce projet contribue à l’avancement des connaissances sur l’utilité de la présence de rétroaction dans les simulateurs sur écran lors de la formation infirmière. / Abstract : Background: Feedback on nursing students’ performance when using a screen simulator could contribute to the learning and development of clinical reasoning by supporting metacognition (Zary et al., 2006). To our knowledge, the form and content of this type of feedback remains slightly discussed in scientific literature. Objective: This research project had three objectives. The first was to contribute to the development of a feedback functionality in a screen simulator, the second was to document the perception of its usefulness following a laboratory-guided experimentation with nursing students, and finally, the third objective aimed to describe its overall appreciation of the simulator. Methods: A descriptive research design with mixed methods was used with a convenience sample of nursing students of a university in Quebec. The PROMPTED feedback model (Rudland et al., 2013) was chosen to guide the conception of feedback in the screen simulator. Access to the simulator was via a web link and subsequently, the participants had to complete a self-administered web questionnaire of their appreciation of the feedback provided during the simulation as well as the screen simulator per se. In addition, interviews were conducted to enrich the description of the perceived usefulness of the feedback provided in the screen simulator. Results: Feedback integrated into the screen simulator in accordance with the PROMPTED Model has helped to guide and to inform the students during the activity. The data collected suggest the use of reel-time continuous feedback rather than only giving the answers at the end of the exercise. Conclusion: In addition to the value upgrade of the screen simulator compared to what is on the market, this project has contributed to the advancement of knowledge on the usefulness of feedback in screen simulators in nursing education.

Magister Scientiae - MSc / Background and objectives: Apoptosis is a process in which a cell programmes its own death. It is a highly organized physiological mechanism in which injured or damaged cells are destroyed. Apart from physiological stimuli however, exogenous factors can induce apoptosis. Many anti-cancer drugs work by activating apoptosis in cancer cells. Natural substances have been found to have the ability to induce apoptosis in various tumour cells and these substances have been used as templates for the construction of novel lead compounds in anticancer treatment. On the other hand, alkylating agents such as cisplatin, cis- [PtCl2 (NH3) 2] have been widely used as antineoplastic agents for a wide variety of cancers including testicular, ovarian, neck and head cancers, amongst others. However, the use of cisplatin as an anticancer agent is limited due to toxicity and resistance problems. The aim of this present study was to screen the leaves of Rhus laevigata, a South African indigenous plant, for the presence of pro-apoptotic and anti-proliferative natural compounds and also to screen newly synthesised palladium based complexes (15 and 57) and a platinum based complex (58) for their antineoplastic activities tested against a panel of cell lines. Results. The results showed that crude methanol extracts from Rhus laevigata as well as the newly synthesised palladium based complexes (15 and 57) and a platinum based complex (58) induced apoptosis in the cell lines tested, as demonstrated by the externalization of phosphatidylserine, mitochondrial membrane permeabilization,caspase-3 activation, and DNA fragmentation. Caski (cervical cancer) and H157 (non small cell lung carcinoma) cell lines treated with the methanol extract from Rhus laevigata however, were more resistant to apoptosis induction. Among the metallocomplexes, complexes 15 and 57, palladium based complexes, were the most active. Conclusion: The methanol extract from the leaves of Rhus laevigata contain pro-apoptotic and antiproliferative natural compound(s), which need to be characterised and elucidated as they could provide the much-needed lead compounds in the fight against cancer. On the other hand the newly synthesized palladium complexes also need further evaluation to see if they can be used as anticancer agents that can overcome the problems associated with cisplatin. / South Africa

Vers le milieu du XIIe siècle, l’église abbatiale de Saint-Michel-de-Cuxa fut dotée d’une « tribune », profond jubé développé sur deux travées. Vraisemblablement démontée au cours du XVIe siècle, elle n’est plus connue aujourd’hui que par 180 éléments architecturaux et sculptés éparpillés en France et à l’étranger. Depuis sa découverte dans les années 1950, cet aménagement liturgique monumental en marbre rose a fait l’objet de plusieurs tentatives de reconstitution. Les divergences observées entre ces précédentes propositions sont nombreuses et portent sur l’inventaire des éléments qui proviennent de l’édicule, son emplacement dans la nef, la forme de cette architecture et l’assemblage des sculptures au sein de celle-ci.Le corpus des pièces conservées est suffisamment représentatif pour en proposer une anastylose numérique. Ce mot, du grec anastellein « remonter », désigne une tentative de reconstitution en trois dimensions d’un monument disparu, à partir du remontage des éléments qui en proviennent. En l’absence de témoignages précis (textuels ou iconographiques), c’est l’examen attentif des pierres qui permet la formulation de nouvelles hypothèses. Au cours de cette recherche, une méthodologie inédite pour l’étude de fragments épars issus d’ensembles démontés en vue de leur anastylose a été formalisée et testée. Toutes les pièces attribuées à l’ancienne « tribune » ont été numérisées et intégrées à cette proposition de restitution en trois dimensions.Cette dernière a apporté une meilleure connaissance de l’architecture et du décor sculpté, renouvelant la discussion sur cet objet artistique, liturgique et historique. Ainsi, son iconographie, ses fonctions, sa datation et le contexte de sa commande ont pu être précisés. / In the middle of the twelfth century, the abbatial church of Saint-Michel-de-Cuxa was endowed with a ''tribune'', a deep choir screen built on two bays. Dismantled in the sixteenth century this ''tribune'' is only known today by its 180 pink marble sculptures scattered throughout France and abroad. Since its discovery in the 1950’s, several attempts have been made to reconstruct this liturgical nonpareil of architecture. Their results differ on several points : the inventory, the location of the construction in the nave of the abbey church, the shapes of the structure and the positioning of the sculptures themselves.The stones preserved, numerous and varied in nature, are sufficient to allow a 3D reconstruction in the form of a digital anastylosis. From the Greek word, anastellein, “to rebuild,” this study appoints an attempt to digitally reconstruct the disappeared monument from its remaining elements. With no contemporaneous descriptions or representations that of the tribune and lacking precise textual and iconographic evidence, it is the careful analysis of the stones themselves that allow the formulation of a new hypotheses. Through this research, a new methodology for the study of the scattered fragments issued from the dismantled structure has been developed and tested for the purpose of their anastylosis. Every stone attributed to the ancient ''tribune'' has been digitized and integrated in the proposition of a 3D reconstruction.The latter has brought a better understanding of the sculpted set and its architecture, renewing discussions on the structure's artistic, liturgical and historical aspects. Thus bringing clarity to its iconography, functions, dating and context of commissioning.

No description available.

Thermoelectric generators (TEG) directly convert heat energy into electrical energy. The impediments as to why this technology has not yet found extensive application are the low conversion efficiency and high costs per watt. On the one hand, the manufacturing process is a cost factor. On the other, the high-­‐priced thermoelectric (TE) materials have an enormous impact on the costs per watt. In this thesis both factors will be examined: the production process and the selection of TE materials. Technical screen printing is a possible way of production, because this method is very versatile with respect to the usable materials, substrates as well as printing inks. The organic conductor PEDOT:PSS offers reasonable thermoelectric properties and can be processed very well in screen printing. It was demonstrated by prototypes of fully printed TEGs that so-­‐called vertical printed TEGs are feasible using standard graphic arts industry processes. In addition, the problems that occur with print production of TEGs are identified. Finally, approaches to solve these problems are discussed.

Recent research suggests that sedentary behaviours have detrimental effects on the health and well-being of children, including effects on obesity. Specifically, television viewing is consistently associated with childhood obesity. Two explanations have been proposed: 1) reduced energy expenditure, and 2) increased food intake. However, it has been suggested that the association between television viewing and childhood obesity may be better explained by an increase in energy intake than by a reduction in energy expenditure. To date, children of different weight status have not been compared in their dietary patterns in front of the television, and it is not known if total sedentary time is linked with food intake in children. The objectives of this thesis are: 1) to determine if obese children consume food more frequently while watching television than normal weight children, and 2) to examine which of television viewing or total sedentary time better predicts dietary patterns in children. Overall, our results re-affirm the notion that television viewing is associated with obesity, although physical activity plays a role in this association. Also, children who are obese consume fast food and fruits/vegetables more frequently during television watching than normal weight children. Furthermore, television viewing appears to be a better predictor of dietary patterns in children than overall sedentary time. Globally, these results provide evidence for the deleterious effects of television viewing on children’s dietary patterns and justification for future intervention studies designed to reduce television viewing in children with obesity.