The exocyst is thought to tether secretory vesicles to specific sites on the plasma membrane. As a member of the exocyst, Sec5 is implicated in cell survival and membrane growth in Drosophila. Little is known of the exocyst function in mammals, with previous work suggesting involvement of exocyst in GTP-dependent exocytosis. Using RNA interference, we stably down-regulated Sec5 in PC12 cells. We found that these knockdown cells exhibit decreased GTP- and Ca2+-dependent exocytosis of dense-core vesicles (DCVs), and contain less proportion of docked vesicles. Expression of Sec6/8 is also slightly reduced in Sec5 knockdown cells. Our results suggest that Sec5 is involved in both GTP- and Ca2+-dependent exocytosis, possibly through the regulation of DCV docking. We also established doxycycline-inducible knockdown system for Sec5 in PC12 cells which may be more appropriate to study development-related proteins. Efforts were also made to re-introduce Sec5 into the Sec5 knockdown cells for rescue purposes.

Research Doctorate - Doctor of Philosophy (PhD) / Slug flow dense phase pneumatic conveying can be a most reliable, efficient method for handling a remarkably wide range of dry bulk solids. Models for pressure drop over slugs in the low-velocity slug-flow pneumatic conveying by many researchers only took the force balance into account with the pressure drop. However, the nature of the slug flow pneumatic conveying is discontinuous and seldom becomes steady during the conveying period which requires further investigation. The fundamental understanding to gas/slug interaction in this thesis is that, by being a dynamic system, the faster a slug moves at a speed, the larger the space is left behind the slug. The gas feeding into the conveying system has to fill the increased space first then permeates through the slug and provides a push force on the slug. With gas permeation rate defined by the permeability factor, the derivative of the upstream pressure based on the air mass conservation law has been developed. For a given conveying system, the pressure in the pneumatic conveying system can be solved for steady conditions or numerically simulated for unsteady conditions. Parametric analysis have been conducted for pressure drop factors and found that slug velocity is the major reason causing the pressure fluctuation in the pneumatic conveying system. To verify the pressure drop model, this model has been applied to single slug cases and compared with experimental results for five different bulk materials, showing good results. Three distinct zones, i.e. Fixed Bed Zone, Initial Slug Zone and Reliable Slug Zone, have been found to exist in the relationship between slip velocity and pressure gradient. Lastly this model has also been applied to a multiple slug system under uniform conditions. In all, the fundamental gas pressure/pressure drop model developed in this thesis approaches slug flow conveying from a different viewpoint from the traditional momentum and material stress models developed by previous researchers, and provides a way of assessing the non-steady flow behaviour in granular dense phase pneumatic conveying. This model not only attains a better understanding of slug flow behaviour but also increases the accuracy of predicting the parameters.

Small amplitude rotational irregularities are observed in a number of rotation-powered pulsars. They fall into two classes: (i) glitches, defined as abrupt increases in the angular velocity of a pulsar (accompanied sometimes by changes in the angular acceleration Ω), of which 286 have been observed in 101 objects; and (ii) timing noise, a continuous stochastic fluctuation in phase, or, which is observed mostly in young and adolescent pulsars (with ages ≥ 10 4 yr). Both classes of irregularity seem to arise from some mechanism that couples the angular momentum of the solid crust and superfluid core of the star, which is activated suddenly when differential rotation exceeds a threshold. Coupling mechanisms proposed to date include catastrophic vortex unpinning in the inner crust, triggered by starquakes; vortex creep, due to thermally activated quantum tunnelling; superfluid-superconductor interactions in the core; and superfluid instabilities. The associated theories are phenomenological, not predictive.

Research Doctorate - Doctor of Philosophy (PhD) / Slug flow dense phase pneumatic conveying can be a most reliable, efficient method for handling a remarkably wide range of dry bulk solids. Models for pressure drop over slugs in the low-velocity slug-flow pneumatic conveying by many researchers only took the force balance into account with the pressure drop. However, the nature of the slug flow pneumatic conveying is discontinuous and seldom becomes steady during the conveying period which requires further investigation. The fundamental understanding to gas/slug interaction in this thesis is that, by being a dynamic system, the faster a slug moves at a speed, the larger the space is left behind the slug. The gas feeding into the conveying system has to fill the increased space first then permeates through the slug and provides a push force on the slug. With gas permeation rate defined by the permeability factor, the derivative of the upstream pressure based on the air mass conservation law has been developed. For a given conveying system, the pressure in the pneumatic conveying system can be solved for steady conditions or numerically simulated for unsteady conditions. Parametric analysis have been conducted for pressure drop factors and found that slug velocity is the major reason causing the pressure fluctuation in the pneumatic conveying system. To verify the pressure drop model, this model has been applied to single slug cases and compared with experimental results for five different bulk materials, showing good results. Three distinct zones, i.e. Fixed Bed Zone, Initial Slug Zone and Reliable Slug Zone, have been found to exist in the relationship between slip velocity and pressure gradient. Lastly this model has also been applied to a multiple slug system under uniform conditions. In all, the fundamental gas pressure/pressure drop model developed in this thesis approaches slug flow conveying from a different viewpoint from the traditional momentum and material stress models developed by previous researchers, and provides a way of assessing the non-steady flow behaviour in granular dense phase pneumatic conveying. This model not only attains a better understanding of slug flow behaviour but also increases the accuracy of predicting the parameters.

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 342-347). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph.D.)--University of Western Australia, 2007.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 362-371). Available also in a digital version from Dissertation Abstracts.

Dans ce mémoire de thèse, nous développons d'abord des multiplications matricielles efficaces. Nous créons de nouveaux ordonnancements qui permettent de réduire la taille de la mémoire supplémentaire nécessaire lors d'une multiplication du type Winograd tout en gardant une bonne complexité, grâce au développement d'outils externes ad hoc (jeu de galets), à des calculs fins de complexité et à de nouveaux algorithmes hybrides. Nous utilisons ensuite des technologies parallèles (multicœurs et GPU) pour accélérer efficacement la multiplication entre matrice creuse et vecteur dense (SpMV), essentielles aux algorithmes dits /boîte noire/, et créons de nouveaux formats hybrides adéquats. Enfin, nous établissons des méthodes de /design/ générique orientées vers l'efficacité, notamment par conception par briques de base, et via des auto-optimisations. Nous proposons aussi des méthodes pour améliorer et standardiser la qualité du code de manière à pérenniser et rendre plus robuste le code produit. Cela permet de pérenniser de rendre plus robuste le code produit. Ces méthodes sont appliquées en particulier à la bibliothèque de calcul exact LinBox. / We first expose in this memoir efficient matrix multiplication techniques. We set up new schedules that allow us to minimize the extra memory requirements during a Winograd-style matrix multiplication, while keeping the complexity competitive. In order to get them, we develop external tools (pebble game), tight complexity computations and new hybrid algorithms. Then we use parallel technologies (multicore CPU and GPU) in order to accelerate efficiently the sparse matrix--dense vector multiplication (SpMV), crucial to /blackbox/ algorithms and we set up new hybrid formats to store them. Finally, we establish generic design methods focusing on efficiency, especially via building block conceptions or self-optimization. We also propose tools for improving and standardizing code quality in order to make it more sustainable and more robust. This is in particular applied to the LinBox computer algebra library.

A function is dened to be hardly e-open provided that theinverse image of each e-dense subset of the codomain that is contained in a proper open set is e-dense in the domain. Characterizations and properties of hardly e-open functionsare presented.

O presente trabalho teve por objetivo realizar a caracterização silvigênica de um trecho de Floresta Ombrófila Densa Sub Montana em conjunto com o estabelecimento de possíveis relações entre as alterações espaciais do mosaico silvático e os fatores abióticos (solo e topografia). O método utilizado foi o de interceptação de linhas de inventário, com identificação das ecounidades descrito por Torquebiau (1986). Foram dispostas linhas paralelas entre si e distantes 10 m uma da outra. Todos os indivíduos dominantes (mais altos naquele ponto), cujas projeções horizontais das copas interceptaram as linhas, foram amostrados na caracterização silvigênica. Foram tomadas medidas, de no mínimo quatro pontos, da projeção horizontal da copa destes indivíduos até as linhas de inventário, em um sistema de eixos ortogonais (coordenadas x e y). Cada árvore marcada no campo foi classificada, quanto à sua arquitetura, em: árvores do futuro, árvores do presente e árvores do passado (OLDEMAN,1987). As áreas de clareira que interceptaram as linhas também foram amostradas, medidas e mapeadas. O estabelecimento das diversas ecounidades em cada trecho amostrado é feito a partir da união das copas de árvores de mesma categoria. O desenho do mosaico e o cálculo das áreas das ecounidades foram feitos por meio do programa TNTmips, a partir das coordenadas das copas dentro das linhas de inventário. Este trabalho resultou na representação gráfica da cobertura vegetal da área estudada e a sua correlação com os fatores abióticos. Para avaliar o papel dos fatores abióticos na composição espacial do mosaico vegetacional, foram analisadas e combinadas as diversas informações em um Sistema de Informações Geográficas (SIG). Para tal, cada \"classe\" de informação constitui um plano de informação ou um \"layer\" dentro do SIG. De acordo com os resultados pode-se concluir que a caracterização silvigênica indicou que a área estudada representa uma floresta em fase de pré-maturidade por apresentar sinais de perturbações recentes, traduzidas nas altas proporções de ecounidades 1A e em reorganização observadas. Conclui-se ainda quepode ser estabelecida uma relação entre a distribuição das ecounidades e os fatores abióticos estudados. / This study aimed to realize the silvigenic characterization of a Dense Rain Forest in according to the establishment of possible relationships between spatial changing\'s on the silvatic standards and some abiotic factors, such as soil and topography. The method applied was the inventory line interception, identifying the ecounits described by Torquebiau (1986). There were set parallel lines in every 10 meters. All dominant trees (the highest in that point), whose horizontal canopy projections intercepted the inventory line, were sampled in the silvigenic characterization. To measure the canopy projection, there were used at least four points on the inventory line as an orthogonal axis system (X and Y coordinates). Each sampled tree was classified based on its architecture features as: trees of the future, trees of the present or trees of the past (OLDEMAN, 1987). The gap surface crossing inventory lines were also measured and mapped. The ecounit establishment is created by the connection of canopies from the same category (future, present or past). The ecounits design were mapped and its surface measured using the TNTmips software, based on all canopies coordinates over the inventory lines. The study resulted in the graphic representation of vegetation coverage and its correlation with abiotic factors. To evaluate the contribution of the abiotic factors on the vegetation mosaic`s spatial composition, a Geographic Information System (GIS) was settled to combine and analyze all data. Different information classes were overlapped as layers on the GIS environment. According to the results it`s possible to conclude that silvigenic characterization indicates that the studied area represents a pre mature forest, based on recent disturbances sings, confirmed on high rates of ecounits as 1A or reorganization types. It is concluded that the silvigenic mapping represented the architectural behavior of the species related to the soil classification.