Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Background: The regenerative function of stem cells from the apical papilla (SCAPs) is affected by the presence of bacteria from infected root canals. Living microorganisms influence SCAP function but the effect of inactive bacteria and its components on SCAPs needs further investigation. Aim: To investigate the effect of residual bacterial products on the proliferation of SCAP under anaerobic conditions. Methods: Five opportunistic bacterial strains from infected dental root canals namely Fusobacterium nucleatum, Enterococcus faecalis, Actinomyces gerensceria, Slackia exigua, and Peptostreptococcaceae yuri, and two probiotic strains Lactobacillus gasseri, Lactobacillus reuteri were used in this study. SCAPs collected from three healthy young patients were exposed to UV-inactivated bacteria or bacterial DNA. Real-Time Cell Analyzer (RTCA) was used to determine real-time proliferation of SCAPs after 80 hours exposure of inactivated bacteria or their DNA. Results: UV killed Fusobacterium nucleatum and Enterococcus Faecalis DNA affects proliferation of stem cells from dental apical papilla as monitored in real-time. Inactivated probiotic species do not affect SCAPs in terms of proliferation. Conclusion:  Inactivated bacteria can affect SCAP function by modulating their proliferation. Further investigations studying SCAP modulation and differentiation are warranted to understand and improve regenerative endodontic procedures.

(in English): This master's thesis focus on the repatriation of Koreans from Japan after World War II. The repatriation process was in many aspects more complicated than it could seem to be at the first sight. A hindrance to the repatriation of more than 2 million Koreans, who were left behind in Japan after the end of war, was vague politics of Supreme Command for Allied Powers (SCAP). SCAP did not possess any specific plan considering Koreans and other foreigners in Japan after its arrival to the Japanese archipelago. Therefore, the government of Japan was the one who seized upon the Korean repatriation and began sending ships from Japan's islands loaded with Korean laborers and soldiers, who were living testimony of its war crimes and a thread for Japanese public order. The government of Japan, however, was limited by number of ships, which it could provide for transportation of Koreans, and by number of available ports. As the waiting time for boarding on a repatriation ship was getting longer and longer, majority of Koreans could not wait anymore. In those cases, they usually decided to rent a small vessel, by which they got transported to the Korean peninsula. Those vessels, however, were making their voyages without a permission and were easy target for pirates or typhoons, which were...

The evolution of cloud computing allows the provisioning of IT resources over the Internet and promises many benefits for both - the service users and providers. Despite various benefits offered by cloud based services, many users hesitate in moving their IT systems to the cloud mainly due to many new security problems introduced by cloud environments. In fact, the characteristics of cloud computing become basis of new problems, for example, support of third party hosting introduces loss of user control on the hardware; similarly, on-demand availability requires reliance on complex and possibly insecure API interfaces; seamless scalability relies on the use of sub-providers; global access over public Internet exposes to broader attack surface; and use of shared resources for better resource utilization introduces isolation problems in a multi-tenant environment. These new security issues in addition to existing security challenges (that exist in today's classic IT environments) become major reasons for the lack of user trust in cloud based services categorized in Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS) or Infrastructure-as-a-Service (IaaS). The focus of this thesis is on IaaS model which allows users to lease IT resources (e.g. computing power, memory, storage, etc.) from a public cloud to create Virtual Machine (VM) instances. The public cloud deployment model considered in this thesis exhibits most elasticity (i.e. degree of freedom to lease/release IT resources according to user demand) but is least secure as compared to private or hybrid models. As a result, public clouds are not trusted for many use cases which involve processing of security critical data such as health records, financial data, government data, etc. However, public IaaS clouds can also be made trustworthy and viable for these use cases by providing better transparency and security assurance services for the user. In this thesis, we consider such assurance services and identify security aspects which are important for making public clouds trustworthy. Based upon our findings, we propose solutions which promise to improve cloud transparency thereby realizing trustworthy clouds. The solutions presented in this thesis mainly deal with the secure life cycle management of the user VM which include protocols and their implementation for secure VM launch and migration. The VM launch and migration solutions ensure that the user VM is always hosted on correct cloud platforms which are setup according to a profile that fulfills the use case relevant security requirements. This is done by using an automated platform security audit and certification mechanism which uses trusted computing and security automation techniques in an integrated solution. In addition to provide the assurance about the cloud platforms, we also propose a solution which provides assurance about the placement of user data in correct and approved geographical locations which is critical from many legal aspects and usually an important requirement of the user. Finally, the assurance solutions provided in this thesis increase cloud transparency which is important for user trust and to realize trustworthy clouds.

This work deals with security compliance of computer systems, namely operating systems, applications and system services. Concept of security policies, their evaluation and their enforcement is described. Security compliance automation and the SCAP standard are presented. OpenSCAP project, which is used as an SCAP scanner, is described together with its tools and its usage. An idea to add support of Microsoft Windows within OpenSCAP, which was previously unsupported, is presented. The core part of the thesis is to identify necessary changes of OpenSCAP and to design an extension of this project. All these modifications are implemented. The solution is demonstrated on security policies for Windows. The solution is evaluated and further improvements are discussed.

Cílem této práce je nastudovat a zjednodušeně popsat standardy SCAP používané pro standardizované předávání informací o zranitelnostech a dalších dat souvisejících s informační bezpečností, se zaměřením na formáty XCCDF a OVAL. V textu jsou zkoumány existující přístupy a nástroje sloužící k tvorbě obsahu těchto standardů. Na základě získaných poznatků je navržen nový nástroj s cílem řešit nedostatky existujících přístupů. Text práce také popisuje implementaci a testování navrženého nástroje.

Orientador: Ricardo Utsunomia / Resumo: Pesticidas organofosforados são muito utilizados na agricultura, mas são tóxicos para muitos organismos incluindo os seres humanos, podendo atuar como desreguladores endócrinos e como agentes mutagênicos e carcinogênicos. Um dos efeitos desreguladores é a alteração do metabolismo lipídico, que está associado também ao desenvolvimento do câncer. Isso pode ser explicado pela necessidade das células tumorais em utilizar ácidos graxos para compor suas membranas em construção. Dentre os pesticidas organofosforados está o Diclorvós (DDVP), cujo alto consumo e utilização se baseia em sua grande eficácia e baixo custo. Neste sentido, o objetivo do presente estudo foi avaliar a influência do praguicida DDVP sobre os marcadores moleculares do metabolismo lipídico (SREBP, SCAP, LIMP-II e CD36) na próstata de ratos após indução química pelo carcinógeno N-metil-N-nitrosoureia (MNU). Foram utilizados 32 ratos da linhagem Fischer 344, com idade de 90 dias. Os ratos foram separados em quatro grupos experimentais: Controle, DDVP, MNU, MNU+DDVP. Foram feitas análises histopatológicas, imuno-histoquímicas e Western Blotting na próstata ventral dos ratos. Na análise histopatológica, os grupos MNU e MNU+DDVP apresentaram 100% de incidência de hiperplasia. Para a avaliação morfométrico-estereológica, o grupo MNU+DDVP apresentou aumento do volume relativo de epitélio quando comparado com o grupo controle. As proteínas SREBP e CD36 foram encontradas nas células epiteliais luminais na região do Apare... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Organophosphate pesticides are widely used in agriculture, but are toxic to many organisms including humans, and can act as endocrine disrupters and as mutagenic and carcinogenic agents. One of the deregulatory effects is the alteration of lipid metabolism, which is also associated with cancer development. This may be explained by the need for tumor cells to use fatty acids to compose their building membranes. Among the organophosphate pesticides, Dichlorvos (DDVP) is one of the most effective and least expensive. Therefore, the objective of the present study was to evaluate the influence of the DDVP pesticide on the molecular markers of lipid metabolism (SREBP, SCAP, LIMP-II and CD36) in rat prostate after chemical induction by the carcinogen N-methyl-N-nitrosourea (MNU). Thirty two rats from the Fischer 344 lineage aged 90 days were used. The rats were separated into four experimental groups: Control, DDVP, MNU and MNU + DDVP. Histopathological, immunohistochemical and Western Blotting analyzes of the ventral prostate of rats were performed. In the histopathological analysis, the MNU and MNU + DDVP groups had a 100% incidence of hyperplasia. For the morphometric-stereological evaluation, the MNU + DDVP group showed an increase in the relative volume of epithelium when compared with the control group. The SREBP and CD36 proteins were found in luminal epithelial cells in the Golgi Apparatus region, SCAP mainly in the apical region, and LIMP II dispersed in the cytoplasm as cl... (Complete abstract click electronic access below) / Mestre

Introduction: Pulp necrosis in immature permanent teeth stops root development and may lead to higher risk of cervical fractures and a challenging treatment. Regenerative endodontic treatment (RET) aims to continue tooth development and implies the use of calcium silicate-based cements, such as Mineral trioxide aggregate (MTA) and Biodentine to seal the root canal. However, its effect on stem cells has been poorly explored.  Aims: Examine the effect of two different calcium silicate-based cements on the viability and the odonto-/osteogenic potential of Stem Cells from Apical Papilla (SCAP). Material and method:  Isolated SCAPs from three healthy donors (donor I, II and III) were used and exposed for different concentration extracts of ProRoot® MTA and BiodentineTM for 21 days. Cell viability was studied using the neutral red cytotoxicity test. Osteogenic differentiation was analyzed by the alkaline phosphatase test (ALP). Results:  No difference in SCAPs viability was detected by the type of cements used, Biodentine or ProRoot MTA. However, material concentration could be associated with cells cytotoxicity.  Osteogenic differentiation was not based on the type of cement used but the environment conditions (aerobic/anaerobic) and the genetical background. Conclusions: The type of cement used in RET, Biodentine or MTA, showed similar effect on SCAPs viability and differentiation potential in vitro. Further studies should be performed to analyze their effect -in -vivo.

Cílem této práce je vytvořit systém, který je schopný automaticky určit množinu testů, které mají být spuštěny, když dojde v ComplianceAsCode projektu ke změně. Navržená metoda vybírá množinu testů na základě statické analýzy změněných zdrojových souborů, přičemž bere v úvahu vnitřní strukturu ComplianceAsCode. Vytvořený systém je rozdělen do čtyř částí - získání změn s využitím verzovacího systému, statická analýza různých typů souborů, zjištění souborů, které jsou ovlivněny těmi změnami, a výpočet množiny testů, které musí být spuštěny pro danou změnu. Naimplementovali jsme analýzu několika různých typů souborů a náš systém je navržen tak, aby byl jednoduše rozšiřitelný o analýzy dalších typů souborů. Vytvořená implementace je nasazena na serveru, kde automaticky analyzuje nové příspěvky do ComplianceAsCode projektu. Automatické spouštění informuje přispěvatelé a vývojáře o nalezených změnách a doporučuje, které testy by pro danou změnu měly být spuštěny. Tím je ušetřen čas strávený při kontrole správnosti příspěvků a čas strávený spouštěním testů.