<p>The need for AAA protocols in the world are increasing and todays most common protocols RADIUS and TACACS+, cannot cope with the fast advances in fields benefiting from the use of AAA protocols. This is why IETF has developed the protocol Diameter as a next generations AAA protocol. The objective of this thesis is to account for the work conducted with Diameter as well as to determine if it is going to become the major AAA protocol of the next generation. In this thesis, I describe what Diameter is, its close integration with the Mobile IP protocol and its other uses. As Diameter is based on RADIUS an introduction to AAA and RADIUS is given in order to comprehend where we are today and where we are going as well as to why. I also compare today’s protocols (RADIUS, TACACS+, Kerberos and COPS) against the next generations AAA protocol Diameter. From this comparison, the Mobile IP integration capabilities and an analysis of the support of the Diameter protocol I have come to the conclusion that Diameter is going to become the major AAA protocol of the next generation.</p>

隨著無線網路環境的普及，越來越多行動工作者可以透過隨身的手持設備進行網路漫遊，即時地存取不同的服務。另外亦可以經由公司的虛擬專有網路來存取企業內部資料、電子郵件及其它應用程式。不論是針對企業或是網路服務業者而言，為了要能夠確保網路環境上的安全性，眾多的行動工作者在進行漫遊時，身分必須被驗證，進而才能被授予各項服務的存取權。此外，還必需根據使用者服務使用的情況進行計費，來提升服務提供者的收益。 因此在無線區域網路中，結合一套認證、授權、計費的架構(Authentication, Authorization, Accounting Architecture, AAA Architecture)，使得網路服務業者能夠有效地來管理龐大行動工作者的跨網路漫遊服務。 本研究提出一個以情境知覺運算(context-aware computing)為基礎的AAA架構。以情境來設計資源存取政策，因此系統偵測到行動工作者情境上的改變，根據已定義好的存取政策，動態地進行身分驗證及調整授權服務，最後再依不同的服務使用等級、連線時間與網路使用量等來計費。本論文以漫遊服務與企業虛擬專有網路為例，說明在此架構下如何針對不同的情境進行身分認證、與服務授權。 / With the popularity of the Wireless LAN, mobile workers are able to access various services or resources with seamless roaming, as well as mobile VPN, just via their handheld devices. Not only for the corporations but the Internet Service Providers(ISP), a secure and trusted remote access is required. User identity should be authenticated in advance, and the service providers grant or deny mobile users the access to resources according to their statuses. Besides, a usage-based accounting and billing is crucial to provide commercialized services within WLAN, and to benefit those service providers. As a result, a AAA architecture designed for coordinating the authentication, authorization and accounting between different administrative networks is required with urgent need. The objective of this research is to provide a context-aware based AAA architecture which adopts context as the design principle to define access control policies. So the system can detect the changing contexts of mobile workers, re-authenticate user identity, adjust dynamically service permissions in the light of context-based access control policies, and bill the user taking into account the contexts efficiently. In this research, we take examples of roaming services and VPN to describe how the architecture works.

La protéine p97/VCP est un membre de la famille des ATPase AAA+ et joue un rôle majeur dans de nombreux processus cellulaires tel que le contrôle de l’homéostasie protéique ou de fonctions associées à la chromatine (transcription, réplication, dommage à l’ADN, progression du cycle cellulaire). De plus, la protéine p97/VCP est impliquée dans un nombre croissant de maladies dont les cancers où il a été montré qu’elle contribue à l’homéostasie protéique et l’adaptation au stress oncogéniques. En effet, l’expression de la protéine p97/VCP est augmentée dans de nombreux cancers et dans certains cas corrèle avec une récurrence de la tumeur et un mauvais pronostique pour les patients. Cependant, le mécanisme moléculaire précis par lequel la protéine p97/VCP régule l’homéostasie protéique des cellules tumorales reste incertain. Pour remédier à cela, nous avons démontré un rôle de la protéine p97/VCP dans le contrôle de l’expression des gènes lors du stress du Réticulum Endoplasmique (RE). Nous avons trouvé que en conditions basales, la protéine RuvBL2 fait partie d’un complexe remodeleur de la chromatine qui contient les protéines HDAC1 et mSin3A et agit comme un répresseur des gènes de stress du RE. De plus, nous avons identifié le gène Gli1, un effecteur connu de la voie de signalisation Hedgehog comme cible de la protéine p97/VCP et du complexe RuvBL2-HDAC1-mSin3A. Ainsi en condition de stress du RE, la voie de signalisation Hedgehog qui a été impliqué dans le développement de cancers est activée. Globalement, nos travaux indiquent que p97/VCP agit comme un interrupteur moléculaire pour inactiver le complexe répresseur RuvBL2-HDAC1 en condition de stress du RE et ainsi activer les gènes de stress du RE et de la voie de signalisation Hedhehog de façon non-canonique. / P97/VCP is a member of the AAA+ ATPase family that plays major roles in various cellular processes including control of protein homeostasis and chromatin-associated functions (transcription, replication, DNA damage, cellular cycle progression). Moreover, p97/VCP is involved in a growing number of diseases including cancers in which it has been shown to contribute to protein homeostasis and adaptation to oncogenic stresses. Indeed, p97/VCP expression is increased in numerous cancers and in some cases correlates with tumor recurrence and poor prognosis for patients. However, the precise mechanism by which p97/VCP regulates tumor cell proteostasis remains unclear. To address this, we demonstrated a role of p97/VCP in gene expression control upon endoplasmic reticulum (ER) stress. We found that in basal conditions, RuvBL2 is part of chromatin remodeler complex that included HDAC1 and mSin3A and act as a repressor of ER stress genes. However under ER stress, ubiquitinylated RuvBL2 is degraded by p97/VCP thus causing activation of ER stress genes. Moreover, we have identified GLI1, a known effector of Hedgehog signaling, as a target of the p97/VCP and RuvBL2-HDAC1-mSin3A complex. As a result under ER stress conditions, the Hedgehog pathway which have been linked to cancer development is non-canonically activated. Overall, our work indicated that p97/VCP acts as a molecular switch to inactivate RuvBL2-HDAC1 repressor complex under ER stress thus activating ER stress genes and Hedgehog genes in a non-canonical manner.

The need for AAA protocols in the world are increasing and todays most common protocols RADIUS and TACACS+, cannot cope with the fast advances in fields benefiting from the use of AAA protocols. This is why IETF has developed the protocol Diameter as a next generations AAA protocol. The objective of this thesis is to account for the work conducted with Diameter as well as to determine if it is going to become the major AAA protocol of the next generation. In this thesis, I describe what Diameter is, its close integration with the Mobile IP protocol and its other uses. As Diameter is based on RADIUS an introduction to AAA and RADIUS is given in order to comprehend where we are today and where we are going as well as to why. I also compare today’s protocols (RADIUS, TACACS+, Kerberos and COPS) against the next generations AAA protocol Diameter. From this comparison, the Mobile IP integration capabilities and an analysis of the support of the Diameter protocol I have come to the conclusion that Diameter is going to become the major AAA protocol of the next generation.

This dissertation work focusses on using information about the location of the user during the authentication process on computer networks. With the growth of mobile computer devices over the last two decades the physical location of users is becoming one of the main issues for access management. This work researches existing solutions which are divided in to two groups related to the source of location information (SATNAV systems for example GPS and based on communication with active infrastructure such as GSM, Wi-Fi). This work shows the methodology for evaluating authentication data which use the principle of fuzzy logic. In comparison with binary logic it is possible to evaluate authentication data accurately. As a result of the authentication process the information is of a higher value, which can be taken into account when setting the levels of user privileges. An important aspect of working with location information is that the user is located in the same place and from where they are asking for access to the system. Solving this question could be linking user biometrics for example finger prints. This principle is used in two types of microelectronic authentication terminals which were developed in conjunction with this work. The first type of terminal uses a SATNAV receiver and an ISM wireless communication module as a source of location information. On the first type of authentication terminal newly developed authentication techniques were tested. The users biometrics are checked by finger print sensor with embedded processing. In the second type authentication terminal a Wi-Fi and GSM module were added for location purposes. In the conclusion of this dissertation the testing methodology of the data authorization and evaluation process of the second type of microelectronic authentication terminal is shown. This confirms the practicality of the suggested methodology and the time-space information in the authentication process.

Abdominal aortic aneurysm (AAA) disease involves a dilation of the aorta below the renal arteries. If the aneurysm becomes sufficiently dilated and tissue strength is less than vascular pressure, rupture of the aorta occurs entailing a high mortality rate. Despite improvements in surgical technique, the mortality rate for emergency repair remains high and so an accurate predictor of rupture risk is required. Inflammation and the associated recruitment of monocytes into the aortic wall are critical in the pathology of AAA disease, stimulating the degradation and remodeling of the vessel wall. Areas with high concentrations of macrophages may experience an increase in tissue degradation and therefore an increased risk of rupture. Determining the magnitude and distribution of monocyte recruitment can help us understand the pathology of AAA disease and add spatial accuracy to the existing rupture risk prediction models. In this study finite element computational fluid dynamics simulations of AAA haemodynamics are seeded with monocytes to elucidate patterns of cell deposition and probability of recruitment. Haemodynamics are first simulated in simplified AAA geometries of varying diameters with a patient averaged flow waveform inlet boundary condition. This allows a comparison with previous experimental investigations as well as determining trends in monocyte adhesion with aneurysm progression. Previous experimental investigations show a transition to turbulent flow occurring during the deceleration phase of the cardiac cycle. There has thus far been no investigation into the accuracy of turbulence models in simulating AAA haemodynamics and so simulations are compared using RNG κ − ε, κ − ω and LES turbulence models. The RNG κ − ε model is insufficient to model secondary flows in AAA and LES models are sensitive to inlet turbulence intensity. The probability of monocyte adhesion and recruitment depends on cell residence time and local wall shear stress. A near wall particle residence time (NWPRT)model is created incorporating a wall shear stress-limiter based on in vitro experimental data. Simulated haemodynamics show qualitative agreement with experimental results. Peaks of maximum NWPRT move downstream in successively larger geometries, correlating with vortex behaviour. Average NWPRT rises sharply in models above a critical maximum diameter. These techniques are then applied to patient-specific AAAs. Geometries are created from CT slices and velocity boundary conditions taken from Phase Contrast-MRI (PC-MRI) data for 3 patients. There is no gold standard for inlet boundary conditions and so simulations using 3 velocity components, 1 velocity component and parabolic flow profiles at the inlet are compared with each other and with PC-MRI data at the AAA midsection. The general trends in flow and wall shear stress are similar between simulations with 3 and 1 components of inlet velocity despite differences in the nature and complexity of secondary flow. Applying parabolic velocity profiles, however, can cause significant deviations in haemodynamics. Axial velocities show average to good correlation with PC-MRI data though the lower magnitude radial velocities produce high levels of noise in the raw data making comparisons difficult. Patient specific NWPRT models show monocyte infiltration is most likely at or around the iliac bifurcation.

Previously, gp16, the ATPase protein of phi29 DNA packaging motor, was an enigma due to its tendency to form multiple oligomeric states. Recently we employed new methodologies to decipher both its stoichiometry and also the mechanism in which the protein functions to hydrolyze ATP and provide the driving force for DNA packaging. The oligomeric states were determined by biochemical and biophysical approaches. Contrary to many reported intriguing models of viral DNA packaging, it was found that phi29 DNA packaging motor permits the translocation of DNA unidirectionally and driven cooperatively by three rings of defined shape. The mechanism for the generation of force and the role of adenosine and phosphate in motor motion were demonstrated. It was concluded that phi29 genomic DNA is pushed to traverse the motor channel section by section with the aid of ATPase gp16, similar to the hexameric AAA+ family in the translocation of dsDNA. A new model of "Push through a One-way Valve" for the mechanism of viral DNA packaging motor was coined to describe the coordinated interaction among the hexameric packaging ATPase gp16 and the revolution mechanism of the dodecameric channel which serves as a control device to regulate the directional movement of dsDNA.

This thesis answers the question of whether and to what extent the goals of PISA align with the Manitoba Government’s goals and priority action areas, and whether the published results of PISA 2012 provide information that addresses the Manitoba Government’s education goals and priority action areas, within the context of mathematics. This thesis provides a qualitative analysis of three PISA 2012 documents, and explores and compares Manitoba PISA 2012 achievement data to Manitoba grade 9 mathematics credit achievement data for English and Français program students, EAL and Aboriginal students to determine whether and to what extent the goals of PISA align with the goals and priority action areas of Manitoba Education and Training, and whether the published results of PISA 2012 provide information addressing the goals and priority action areas of Manitoba Education and Training, within the context of mathematics. / February 2017

Doctor of Philosophy / Department of Biochemistry / Michal Zolkiewski / ClpB is a bacterial heat-shock protein that disaggregates and reactivates strongly aggregated proteins in cooperation with the DnaK chaperone system. ClpB contains two ATP-binding AAA+ modules, a linker coiled-coil domain, and a highly mobile N-terminal domain. It forms ring-shaped hexamers in a nucleotide-dependent manner. The unique aggregation reversing chaperone activity of ClpB involves ATP-dependent translocation of substrates through the central channel in the ClpB ring. The initial events of aggregate recognition and the events preceding the translocation step are poorly understood. In addition to the full-length ClpB95, a truncated isoform ClpB80, that is missing the whole N-terminal domain, is also produced in vivo. Various aspects of the structure and function of ClpB were addressed in this work. The thermodynamic stability of ClpB in its monomeric and oligomeric forms, as well as the nucleotide-induced conformational changes in ClpB were investigated by fluorescence spectroscopy. Equilibrium urea-induced unfolding showed that two structural domains-the small domain of the C-terminal AAA+ module and the coiled-coil domain-were destabilized in the oligomeric form of ClpB, which indicates that only those domains change their conformation or interactions during formation of the ClpB rings. Several locations of Trp-fluorescence probes were also found to respond to nucleotide binding. The biological role of the two naturally-occurring ClpB isoforms was also investigated. We discovered that ClpB achieves optimum chaperone activity by synergistic cooperation of the two isoforms that form hetero-oligomers. We found that ClpB95/ClpB80 hetero-oligomers form preferentially at low protein concentration with higher affinity than homo-oligomers of ClpB95. Moreover, hetero-oligomers bind to aggregated substrates with a similar efficiency as homo-oligomers of ClpB95, do not show enhanced ATPase activity over that of the homo-oligomers, but display a strongly stimulated chaperone activity during the reactivation of aggregated proteins. We propose that extraction of single polypeptides from aggregates and their delivery to the ClpB channel for translocation is the rate-limiting step in aggregate reactivation and that step is supported by the mobility of the N-terminal domain of ClpB. We conclude that the enhancement of the chaperone activity of the hetero-oligomers is linked to an enhancement of mobility of the N-terminal domains.

Les protéasomes sont de larges protéases ATP-dépendante impliquées dans la dégradation des protéines régulatrices et des protéines anormales dans la cellule. Cette thèse porte sur l'étude de deux AAA-ATPases : Pans A et Pans B régulatrices du protéasome chez les archaea halophiles. Une partie de ce manuscrit est consacrée à la caractérisation du mode de régulation des deux Pans chez l'Archaea halophile extrême Halobacterium salinarium. Les expériences montrent l'existence de deux isoformes des protéines Pans dans les cellules. Les modifications portent sur la région N-ter des deux protéines et mettent probablement en jeu l'utilisation alternative de deux départs de traduction. La cartographie des régions 5' non codantes des transcrits révèle l'existence d'une hétérogénéité au niveau des ARNm des pans. Le travail s'intéresse ensuite aux états d'oligomérisation et d'association in cellulo des protéines PANs. Des études de fractionnement par ultracentrifugation sur gradient de sucrose indiquent un état de faible oligomérisation des PANs et l'absence de complexes stables avec le protéasome 20S. La dernière partie du travail porte sur la régulation de l'expression des gènes panA et panB au cours de la réponse aux stress salin et thermique. Ce travail montre que les deux protéines Pans, activatrices potentielles du protéasome, ne sont pas régulées de façon identique en réponse à un stress environnemental.