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Klasila, A. (Aleksi). "TryTLS:testing TLS libraries." Bachelor's thesis, University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201712203359.
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Encryption is a fundamental building block in protecting our privacy and safety of our society, unfortunately we may fail to use it properly. TLS (Transport Layer Security) has an important part in encrypting the connections on the Internet today. SSL (Socket Layer Security) is the deprecated and dangerous version of TLS. SSL should not be used anymore. There are many protocols developed that use TLS. For example: HTTPS (Hypertext Transfer Protocol Secure), FTPS (File Transfer Protocol with support for TLS) and IMAP (Internet Message Access Protocol). All the protocols using TLS have also got many different implementations in different programming languages and libraries. This thesis researches the tools used to test how different (client-) libraries implement TLS. This thesis also researches the known TLS/SSL vulnerabilities. In this thesis a backed for TLS testing purposes is implementedSalaus on perusrakenneosa yksityisyyden ja turvallisuuden suojaamisessa yhteiskunnassamme, valitettavasti saatamme suoriutua siinä huonosti. TLS:llä (Transport Layer Security) on nykyisin tärkeä osa Internet-liikenteen salaamisessa. SSL (Socket Layer Security) on TLS:n vanhentunut ja vaarallinen edeltäjä. SSL:ää ei pitäisi käyttää enään nykyisin. On olemassa monia protokollia, kuten HTTPS (Hypertext Transfer Protocol Secure), FTPS (File Transfer Protocol with support for TLS) ja IMAP (Internet Message Access Protocol), jotka käyttävät TLS:ää. Lisäksi, kaikilla TLS:ää käyttävillä protokollilla on useita toteutuksia eri ohjelmointikielillä ja kirjastoilla. Tässä työssä tutkitaan kehitettyjä työkaluja TLS-kirjastojen testaamiseen. Tässä työssä tutkitaan myös tunnettuja TLS/SSL-haavoittuvuuksia. Tässä työssä rakennetaan lisäksi järjestelmä TLS:n testaamista varten
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McLeary, Alwyn. "Dynamic response of TLPs during tether installation." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394952.
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Li, Jiatong. "TLS Library for Isolated Enclaves : Optimizing the performance of TLS libraries for SGX." Thesis, KTH, Kommunikationssystem, CoS, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-241245.
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Nowadays cloud computing systems handle large amounts of data and process this data across different systems. It is essential to considering data security vulnerabilities and data protection. One means of decreasing security vulnerabilities is to partition the code into distinct modules and then isolate the execution of the code together with its data. Intel’s Software Guard Extension (SGX) provides security critical code isolation in an enclave. By isolating the code’s execution from an untrusted zone (an unprotected user platform), code integrity and confidentiality are ensured. Transport Layer Security (TLS) is responsible for providing integrity and confidentiality for communication between two entities. Several TLS libraries support cryptographic functions both for an untrusted zone and an enclave. Different TLS libraries have different performance when used with Intel’s SGX. It is desirable to use the best performance TLS library for specific cryptographic functions. This thesis describes a performance evaluation several popular TLS libraries performance on Intel SGX. Using the evaluation results and combining several different TLS libraries together, the thesis proposes a new solution to improve the performance of TLS libraries on Intel SGX. The performance is best when invoking the best specific TLS library based upon the data size – as there is a crossover in performance between the two best libraries. This solution also maintains the versatility of the existing cryptographic functions.Numera hanterar molnberäkningssystem stora mängder data och bearbetar dessa data över olika system. Det är viktigt att ta itu med datasäkerhetsproblem och dataskydd. Ett sätt att minska säkerhetsproblem är att partitionera koden i olika moduler och sedan isolera kodens exekvering tillsammans med dess data. Intel’s Software Guard Extension (SGX) tillhandahåller säkerhetskritisk kodisolering i en enklav. Genom att isolera kodens körning från en otillförlitlig zon (en oskyddad användarplattform) säkerställs kodintegritet och sekretess. Transport Layer Security (TLS) ansvarar för att ge integritet och konfidentialitet för kommunikation mellan två enheter. Flera TLS-bibliotek stödjer kryptografiska funktioner både för en osäker zon och en enklav. Olika TLS-bibliotek har olika prestanda när de används med Intel’s SGX. Det är önskvärt att använda TLS-bibliotekets bästa prestanda för specifika kryptografiska funktioner. Denna avhandling beskriver en prestationsutvärdering av flera populära TLS-bibliotekens prestanda på Intel SGX. Genom att använda utvärderingsresultaten och kombinera flera olika TLS-bibliotek tillsammans, presenterar avhandlingen en ny design och lösning för att förbättra prestanda för TLS-bibliotek på Intel SGX. Den resulterande prestanda åberopar TLS-bibliotekets bästa prestanda inom en viss datastorlek samtidigt som krypteringsfunktionerna är mångsidiga.
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Moore, Mark. "ST2 & TLRs : coordination of chemokine-driven immunity." Thesis, University of Glasgow, 2009. http://theses.gla.ac.uk/830/.
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Abstract The detection of pathogen-associated molecules by Toll-like receptors (TLRs) is instrumental to the induction and regulation of an inflammatory response. However, prolonged or inappropriate stimulation of TLRs is associated with disease. A family of molecules coded for by the ST2 gene have been implicated as negative regulators of TLR4-signalling in murine cells. Here, the existence and potential role of these ST2 molecules in human macrophages has been investigated. Following the discovery of IL-33 as a ligand for ST2, the effect of this ligand on human macrophages was explored. We found elevated levels of the soluble form of ST2 (sST2) in the synovial fluid (SF) of patients with inflammatory forms of arthritis compared to amount in SF from people diagnosed with a less inflammatory form of arthritis. First confirming that human macrophages express the trans-membrane version of ST2 known as ST2L, we showed these cells respond to a recombinant form of the IL-33 ligand by inducing the release of inflammatory chemokines but not cytokines. The migration of inflammatory cells into inflamed tissue is influenced by their recognition of chemokines. The expression of receptors for these chemokines, the so called chemokine receptors (CCRs) is therefore pivotal in the recruitment of leukocytes into inflamed tissues. The regulation of the CCRs by TLR agonists has recently emerged as a fundamental axis in regulating inflammation. Whilst the local administration of TLR-ligands paradoxically increases leukocyte recruitment to sites of inflammation (thereby exacerbating it), in contrast, low, systemic doses of TLR-ligand have been found to be anti-inflammatory. The work of the second part of this thesis has reinforced the concept that the attenuation of inflammation by systemically-delivered TLR-agonists is due to a reduced migration of leukocytes into sites of inflammation. By adoptively transferring an equal number of discretely labelled cells from WT- and TLR2-KO- mice into WT mice with an existing inflammation, we were able to show that systemic administration of a TLR2 agonist caused a reduction in the number of transferred WT- but not TLR2-KO- cells migrating into the site inflammation. Consistent with this, more WT- than TLR2-KO-cells were detected in the lymph nodes of TLR2 agonist-, but not control- treated mice. For the first time the anti-inflammatory effect of TLR ligands has been shown to work in a cell autonomous manner, i.e. the migratory cells need to detect the TLR ligand directly for their migratory capacity to be diminished.
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Kassem, Ali. "Toll-like receptors (TLRs) and inflammatory bone modeling." Doctoral thesis, Umeå universitet, Institutionen för odontologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-110296.
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Patients with inflammatory or infectious conditions such as periodontitis, peri-implantitis, osteomyelitis, rheumatoid arthritis, septic arthritis and loosened joint prosthesis display varying severity of destruction in the adjacent bone tissue. Bone loss in inflammatory diseases is considered a consequence of cytokine induced RANKL and subsequent enhanced osteoclast formation. Hence, osteotropic cytokines and their receptors have been suggested to be important for the pathogenesis of inflammation-induced osteolysis. It is, here, suggested that bacterial components, so called “pathogen associated molecular patterns=PAMPs”, may also be involved. Varieties of cells express receptors for PAMPs, including Toll-like receptors (TLRs) which are the first line of defence in the innate immune system. LPS (lipopolysaccharide), fimbria and lipoproteins from pathogenic bacteria such as P. gingivalis, S. aureus are ligands for TLR2 and flagellin from pathogenic flagellated bacteria like S. typhimurium is a ligand for TLR5. Since the susceptibility to, or the severity of inflammation-associated bone diseases are likely related to differences in the tissue response, and the mechanisms by which PAMPs interact with bone cells are not fully understood, we aimed to elucidate the importance of different TLRs for inflammation induced bone loss by conducting in vitro and in vivo investigations. Activation of TLR2 and TLR5 in organ cultured mouse parietal bones increased bone resorption in a time- and concentration-dependent manner by a process inhibited by OPG and bisphosphonate, showing the crucial role of RANKL-induced osteoclast formation. In addition, the number of osteoclasts, expression of osteoclastic genes and osteoclastogenic transcription factors were increased. In the bones and in osteoblasts isolated from the bones, TLR2 agonists increased the expression of RANKL without affecting OPG, while TLR5 activation resulted in enhanced RANKL and decreased OPG. Activation of both TLR2 and TLR5 stimulated the expression in both bones and osteoblasts of prostaglandins and pro-inflammatory cytokines, known to stimulate RANKL. By blocking the cytokines and prostaglandin, we showed that TLR2 and TLR5 induced bone resorption and RANKL expression are independent of these molecules. Activation of TLR2, but not TLR5, in mouse bone marrow macrophage cultures inhibited RANKL-induced osteoclast formation, an effect not observed in committed pre-osteoclasts. Local administration in vivo of TLR2 and TLR5 agonists on the top of mouse skull bones enhanced local and systemic osteoclast formation and bone resorption. Using knockout mice, we showed that the effects by LPS from P. gingivalis (used as TLR2 agonist) and flagellins (used as TLR5 agonists) are explicit for TLR2 and TLR5 ex vivo and in vivo, respectively. These data show that stimulation of TLR2 and TLR5 results in bone resorption in vitro and in vivo mediated by increased RANKL in osteoblasts and thus may be one mechanism for developing inflammatory bone loss. Interestingly, histological analyses of skull bones of mice treated locally with TLR2 and TLR5 agonists revealed that the bones not only reacted with locally increased osteoclastogenesis (osteoclast formation), but also with locally increased new bone formation. This was observed on both periosteal and endosteal sides of the bones, as well as in the bone marrow compartment. The formation of new bone was seen close to osteoclasts in some parts, but also in other areas, distant from these cells. The response was associated with active, cuboidal osteoblasts, extensive cell proliferation and increased expression of genes coding for bone matrix proteins and osteoblastic transcription factors. In conclusion, activation of TLR2 and TLR5 in osteoblasts results in bone loss associated with enhanced osteoclast formation and bone resorption, as well as with increased osteoblast differentiation and new bone formation, indicating that inflammation causes bone modeling. The data provide an explanation why LPS from P. gingivalis and flagellin from flagella-expressing bacteria can stimulate bone loss. Since TLR2 and TLR5 can be activated not only by bacterial components, but also by endogenous ligands produced in inflammatory processes, the data also contribute to the understanding of inflammation induced bone loss in autoimmune diseases. Hopefully, these findings will contribute to the development of treatment strategies for inflammation induced bone loss.
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Vinje, Eivind. "Educational implementation of SSL/TLS." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for datateknikk og informasjonsvitenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-13834.
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Levillain, Olivier. "Une étude de l’écosystème TLS." Thesis, Evry, Institut national des télécommunications, 2016. http://www.theses.fr/2016TELE0014/document.
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SSL/TLS, un protocole de sécurité datant de 1995, est devenu aujourd'hui une brique essentielle pour la sécurité des communications, depuis les sites de commerce en ligne ou les réseaux sociaux jusqu'aux réseaux privés virtuels (VPN), en passant par la protection des protocoles de messagerie électronique, et de nombreux autres protocoles. Ces dernières années, SSL/TLS a été l'objet de toutes les attentions, menant à la découverte de nombreuses failles de sécurité et à des améliorations du protocole. Dans cette thèse, nous commençons par explorer l'écosystème SSL/TLS sur Internet en énumérant les serveurs HTTPS sur l'espace IPv4; nous proposons pour cela des méthodologies de collecte et d'analyse permettant d'obtenir des résultats reproductibles et comparables entre différentes campagnes de mesure. Au-delà de ces observations, nous nous sommes intéressés en détail à deux aspects essentiels de la sécurité TLS: comment parer les attaques sur le Record Protocol, et comment implémenter des parsers sûrs et efficaces. Finalement, en se basant sur les nombreuses failles d'implémentation qui ont affecté presque toutes les piles TLS ces dernières années, nous tirons quelques enseignements concernant les difficultés liées à l'écriture d'une bibliothèque TLS de confianceSSL/TLS, a 20-year old security protocol, has become a major component securing network communications, from HTTPS e-commerce and social network sites to Virtual Private Networks, from e-mail protocols to virtually every possible protocol. In the recent years, SSL/TLS has received a lot of attentions, leading to the discovery of many security vulnerabilities, and to protocol improvements. In this thesis, we first explore the SSL/TLS ecosystem at large using IPv4 HTTPS scans, while proposing collection and analysis methodologies to obtain reproducible and comparable results across different measurement campaigns. Beyond these observations, we focused on two key aspects of TLS security: how to mitigate Record Protocol attacks, and how to write safe and efficient parsers. Finally, building on the numerous implementation flaws in almost all TLS stacks in the last years, we propose some thoughts about the challenges in writing a secure TLS library
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Cavalieri, Tássio Antonio. "Emprego do MCNP no estudo dos TLDs 600 e 700 visando a implementação da caracterização do feixe de irradiação na instalação de BNCT do IEA-R1." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-19112013-135350/.
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A Terapia de Captura de Nêutron por Boro (BNCT) é uma terapia de combate ao câncer bimodal, na qual a energia útil da terapia vem da reação nuclear que ocorre pelo Boro quando irradiado com nêutrons térmicos. No IPEN há uma instalação de pesquisas em BNCT, na qual o feixe de radiação contendo nêutrons é proveniente do reator IEA-R1. Como condição desta terapia é necessário realizar a dosimetria do feixe de radiação, que atualmente é feito com o uso de folhas de ativação, para cálculo do fluxo de nêutrons, e do dosímetro TLD 400, para estimativa da dose gama. Para campos mistos de nêutrons e gamas, a Comissão Internacional de Unidades e Medidas (ICRU) recomenda o uso de dosímetros com sensibilidades distintas para as componentes do feixe, como o caso do par TLD 600 e TLD 700 que apresentam sensibilidades distintas a nêutrons térmicos, devido à diferente quantidade do isótopo 6Li em sua composição, o qual apresenta uma alta seção de choque para nêutrons térmicos. Este trabalho constou da realização de simulações e experimentos visando a implementação da metodologia de dosimetria utilizando o par TLD 600 e TLD 700 e sua comparação com a metodologia atualmente utilizada pelo grupo de pesquisa em BNCT, que utiliza o TLD 400. Portanto, foi realizado um estudo das respostas de cada um destes TLDs a partir de irradiações em diferentes campos e sempre utilizando simulações com o MCNP para fornecer a discriminalização das componentes de dose depositadas em cada TLD. Foram realizadas varias irradiações em campo de gama puro e em campo misto de nêutrons e gamas para o estudo da reprodutibilidade destes TLDs. Este estudo mostrou que mesmo TLDs do mesmo tipo têm sensibilidades distintas, e assim foi criado um Fator de Normalização para cada um dos TLDs, eliminando assim a necessidade de selecionamento. Foi realizado um estudo sobre a diferença das respostas destes TLDs devido à diferentes campos. Este estudo mostrou ser possível estimar o fluxo relativo entre gamas e nêutrons a partir da relação existente entre as duas regiões de interesse dos TLDs 600 e 700. Também foi possível observar que o TLD 700 apresenta resposta para nêutrons, e se a recomendação da ICRU for seguida, a resposta devido à radiação gama será superestimada. Foram obtidas as curvas de calibração dose resposta destes TLDs para campos de gamas puro e campos mistos. Este trabalho propõe o uso desta metodologia com o uso do par TLD 600 e TLD 700, por apresentar maior precisão de resposta frente a atual metodologia que utiliza o TLD 400, porém precauções devem ser tomadas para evitar que a dose gama seja superestimada.Boron Neutron Capture Therapy, BNCT, is a bimodal radiotherapic procedure for cancer treatment. Its usefull energy comes from a nuclear reaction driven by impinging thermal neutron upon Boron 10 atoms. A BNCT research facility has been constructed in IPEN at the IEA-R1 reactor, to develop studies in this area. One of its prime experimental parameter is the beam dosimetry which is nowadays made by using activation foils, for neutron measurements, and TLD 400, for gamma dosimetry. For mixed field dosimetry, the International Commmission on Radiation Units and Measuments, ICRU, recommends the use of pair of detectors with distinct responses to the field components. The TLD 600/ TLD 700 pair meets this criteria, as the amount of 6Li, a nuclide with high thermal neutron cross section, greatily differs in their composition. This work presents a series of experiments and simulations performed in order to implement the mixed field dosimetry based on the use of TLD 600/TLD 700 pair. It also intended to compare this mixed field dosimetric methodology to the one so far used by the BNCT research group of IPEN. The response of all TLDs were studied under irradiations in different irradiation fields and simulations, underwent by MCNP, were run in order to evaluate the dose contribution from each field component. Series of repeated irradiations under pure gamma field and mixed field neutron/gamma field showed differences in the TLD individual responses which led to the adoption of a Normalization Factor. From the use of Normalization Factor the TLD selection it has allowed to overcome TLD selection. TLD responses due to different field components and spectra were studied. It has shown to be possible to evaluate the ralative gamma/neutron fluxes from the relative responses observed in the two Regions of Interest of TLDs glow curves, ROIs, from TLD 600 and TLD 700. It has also been possible to observe the TLD 700 response to neutron, which leads to a gamma dose overstimation when one follows the ICRU recommended mixed field dosimetric procedure. Dose response curves were obtained for the distinct types of TLDs for pure gamma and mixed fields. This work recommends the TLD 600/TLD 700 pair methodology for mixed field dosimetry, this methodology presents a better precision than the one based on TLD 400, however one has to be carefull to avoid gamma dose superestimation.
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Sousa, Edi Carlos Pereira de [UNESP]. "Cinética de cristalização em vidros teluritos do sistema TLWN." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/91983.
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sousa_ecp_me_ilha_prot.pdf: 3838753 bytes, checksum: fb1abbca6e1c68797f42ad16a38d7a47 (MD5)Vidros preparados a partir de massa fundida podem nuclear ou cristalizar novas fases quando são submetidos a tratamentos térmicos acima da temperatura de transição vítrea. Neste traba- lho foram apresentados estudos sobre a cinética de cristalização de vidros teluritos do sistema 80TeO2 –10WO3 –(10–x)Li2 O–xNa2 O, x = 0, 2, 4, 6 e 10% mol, denominado sistema TLWN. As principais teorias sobre nucleação e cristalização de vidros foram detalhadas, tais como: Teoria Clássica de Nucleação, Teoria Clássica de Nucleação Modificada, Teoria de Nucleação Adiabática e Teoria JMAK. Classicamente, o estudo da cristalização de vidros pode ser realizado através da teoria formulada por Johnson–Mehl–Avrami–Kolmogorov (JMAK), a qual descreve os processos de nucleação e cristalização, por intermédio das curvas de calorimetria exploratória diferencial – DSC. Os vidros foram sintetizados pelo método de resfriamento rápido (melt–quenching ). Medidas de DSC foram realizadas a diferentes taxas de aquecimento e com diferentes tama- nhos de partículas para estudar a cinética de cristalização dos vidros. Foi evidenciado o caráter amorfo de alguns vidros e para o vidro TLWN6 foram encontradas diferentes fases cristalinas, tais como: Na2 (TeW2 O9 ), Li2 Te2 O5 , WO3 , α–TeO2 e γ–TeO2 , dispersas na matriz devido aos di- versos tratamentos térmicos realizados em torno das temperaturas correspondentes aos máximos dos picos de cristalização e evidenciadas por DRX. Deconvoluções foram realizadas utilizando funções gaussianas para separar os picos sobrepostos da amostra TLWN6. Ficou evidente, por intermédio da análise dos termogramas, que o número de picos de cristalização aumenta com o incremento do óxido de sódio e também que os vidros teluritos deste sistema não possuem boa estabilidade térmica, quando...
The glasses prepared from the melt mass may crystallize or nuclear new phases when subjected to heat treatment above the glass transition temperature. In this work were presented studies on the kinetics of nucleation and crystallization of glasses tellurite of the system 80TeO2 –10WO3 – (10–x)Li2 O–xNa2 O, x = 0, 2, 4, 6 e 10% mol called TLWN system. The main theories on nucleation and crystallization of glasses have been detailed, such as: Classical Theory of Nucle- ation, Modified Classical Theory of Nucleation, the Nucleation Adiabatic Theory and Theory JMAK. Classically, the study of crystallization of glasses can be performed by theory formu- lated by Johnson–Mehl–Avrami–Kolmogorov (JMAK) which describes processes of nucleation and crystallization through of differential scanning calorimetry curves – DSC. The glasses were synthesized by the method of melt - quenching. DSC measurements were made at different hea- ting rates and with different particle sizes to study the crystallization kinetics of glass. It became evident amorphous character of some glasses and glass TLWN6 different crystalline phases have been found, such as Na2 (TeW2 O9 ), Li2 Te2 O5 , WO3 , α–TeO2 e γ–TeO2 , dispersed in the matrix due to the different heat treatments performed in around the temperatures corresponding to the peak maximum crystallization and evidenced by XRD. Deconvolutions were performed using gaussian functions to separate overlapping peaks TLWN6 sample. It became evident through the examination of thermographs, that the number of peaks of crystallization increases with the increase of sodium oxide and also that this system tellurite glasses do not have good thermal stability when compared to traditional glasses. The activation energies of the crystalline pha- ses were obtained using the... (Complete abstract click electronic access below)
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Sousa, Edi Carlos Pereira de. "Cinética de cristalização em vidros teluritos do sistema TLWN /." Ilha Solteira, 2013. http://hdl.handle.net/11449/91983.
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Orientador: Keizo YukimituBanca: João Carlos Silos Moraes
Banca: Walter Maigon Pontuschka
Resumo: Vidros preparados a partir de massa fundida podem nuclear ou cristalizar novas fases quando são submetidos a tratamentos térmicos acima da temperatura de transição vítrea. Neste traba- lho foram apresentados estudos sobre a cinética de cristalização de vidros teluritos do sistema 80TeO2 -10WO3 -(10-x)Li2 O-xNa2 O, x = 0, 2, 4, 6 e 10% mol, denominado sistema TLWN. As principais teorias sobre nucleação e cristalização de vidros foram detalhadas, tais como: Teoria Clássica de Nucleação, Teoria Clássica de Nucleação Modificada, Teoria de Nucleação Adiabática e Teoria JMAK. Classicamente, o estudo da cristalização de vidros pode ser realizado através da teoria formulada por Johnson-Mehl-Avrami-Kolmogorov (JMAK), a qual descreve os processos de nucleação e cristalização, por intermédio das curvas de calorimetria exploratória diferencial - DSC. Os vidros foram sintetizados pelo método de resfriamento rápido (melt-quenching ). Medidas de DSC foram realizadas a diferentes taxas de aquecimento e com diferentes tama- nhos de partículas para estudar a cinética de cristalização dos vidros. Foi evidenciado o caráter amorfo de alguns vidros e para o vidro TLWN6 foram encontradas diferentes fases cristalinas, tais como: Na2 (TeW2 O9 ), Li2 Te2 O5 , WO3 , α-TeO2 e γ-TeO2 , dispersas na matriz devido aos di- versos tratamentos térmicos realizados em torno das temperaturas correspondentes aos máximos dos picos de cristalização e evidenciadas por DRX. Deconvoluções foram realizadas utilizando funções gaussianas para separar os picos sobrepostos da amostra TLWN6. Ficou evidente, por intermédio da análise dos termogramas, que o número de picos de cristalização aumenta com o incremento do óxido de sódio e também que os vidros teluritos deste sistema não possuem boa estabilidade térmica, quando... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The glasses prepared from the melt mass may crystallize or nuclear new phases when subjected to heat treatment above the glass transition temperature. In this work were presented studies on the kinetics of nucleation and crystallization of glasses tellurite of the system 80TeO2 -10WO3 - (10-x)Li2 O-xNa2 O, x = 0, 2, 4, 6 e 10% mol called TLWN system. The main theories on nucleation and crystallization of glasses have been detailed, such as: Classical Theory of Nucle- ation, Modified Classical Theory of Nucleation, the Nucleation Adiabatic Theory and Theory JMAK. Classically, the study of crystallization of glasses can be performed by theory formu- lated by Johnson-Mehl-Avrami-Kolmogorov (JMAK) which describes processes of nucleation and crystallization through of differential scanning calorimetry curves - DSC. The glasses were synthesized by the method of melt - quenching. DSC measurements were made at different hea- ting rates and with different particle sizes to study the crystallization kinetics of glass. It became evident amorphous character of some glasses and glass TLWN6 different crystalline phases have been found, such as Na2 (TeW2 O9 ), Li2 Te2 O5 , WO3 , α-TeO2 e γ-TeO2 , dispersed in the matrix due to the different heat treatments performed in around the temperatures corresponding to the peak maximum crystallization and evidenced by XRD. Deconvolutions were performed using gaussian functions to separate overlapping peaks TLWN6 sample. It became evident through the examination of thermographs, that the number of peaks of crystallization increases with the increase of sodium oxide and also that this system tellurite glasses do not have good thermal stability when compared to traditional glasses. The activation energies of the crystalline pha- ses were obtained using the... (Complete abstract click electronic access below)
Mestre
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Koscielniak, Jan. "Detekce časových postranních kanálů v TLS." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2020. http://www.nusl.cz/ntk/nusl-417261.
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Protokol TLS je komplexní a jeho použití je široce rozšířené. Mnoho zařízení používá TLS na ustanovení bezpečné komunikace, vzniká tak potřeba tento protokol důkladně testovat. Tato diplomová práce se zaměřuje na útoky přes časové postranní kanály, které se znovu a znovu objevují jako variace na už známé útoky. Práce si klade za cíl usnadnit korektní odstranění těchto postranních kanálů a předcházet vzniku nových vytvořením automatizovaného frameworku, který pak bude integrován do nástroje tlsfuzzer, a vytvořením testovacích scénářů pro známé útoky postranními kanály. Vytvořené rozšíření využívá program tcpdump pro sběr časových údajů a statistické testy spolu s podpůrnými grafy k rozhodnutí, zda se jedná o možný postranní kanál. Rozšíření bylo zhodnoceno pomocí nových testovacích skriptů a byla předvedena jeho dobrá schopnost rozlišit postranní kanál. Rozšíření spolu s testy je nyní součástí nástroje tlsfuzzer.
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Novo, Tiago António Gadim. "Melhoramento da resposta sísmica de edifícios com recurso a TLDs." Master's thesis, Universidade de Aveiro, 2008. http://hdl.handle.net/10773/2335.
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Mestrado em Engenharia CivilSismos ocorridos recentemente têm demonstrado, de forma dramática, que a investigação na área da engenharia sísmica deve ser direccionada para a avaliação da vulnerabilidade das construções, geralmente desprovidas de adequadas características resistentes. O seu esforço deve ser realizado reduzindo a sua vulnerabilidade e, consequentemente, o risco para níveis aceitáveis. O estudo e desenvolvimento de novas técnicas e de materiais de reforço têm um papel fundamental no sentido de evitar perdas económicas e vidas humanas. O trabalho desenvolvido nesta dissertação de mestrado centra-se no estudo de um sistema de protecção sísmica de edifícios, Tuned Liquid Damperes(TLDs), que reduzem as vibrações induzidas pelas acções dinâmicas através de fenómenos de oscilação da superfície livre do fluido (sloshing). Este trabalho foi estruturado em duas partes. Na primeira, estudou-se o comportamento de um Tuned Liquid Damper (TLD) isolado quando sujeito a uma excitação sinusoidal na sua base, com diferentes amplitudes de deslocamento. Na segunda parte deste trabalho avaliou-se a eficiência dos TLDs na melhoria da resposta sísmica de um edifício, com base em análises dinâmicas lineares. O edifício estudado é representativo da arquitectura moderna, localizado em Lisboa. ABSTRACT: Recent earthquakes have dramatically revealed that research in the area of earthquake engineering should be directed towards the evaluation of construction vulnerabilities, which are generally devoid of adequate resistance characteristics. Its reinforcement should be made with a view to reducing its vulnerabilities and consequently, the risk to acceptable levels. The study and development of new reinforcement techniques and/or the improvement of seismic performance is fundamental so as to avoid significant economic losses as well as human lives in future events. The work done in this Master's dissertation is centered on the study of an earthquake protection system, the Tuned Liquid Dampers (TLDs), which can reduce the motions induced by the earthquake's effect on buildings, taking into account the oscillation of the fluid free surface (sloshing). This work was divided into two parts. In the first part, the behavior of an isolated Tuned Liquid Damper (TLD), subjected to a sinusoidal excitation at its base, with different displacement amplitudes was studied. In the second part of this work, the efficiency of the TLDs in improving the seismic response of an existing building was evaluated based on linear dynamic analyses. The building in the study is representative of modern architecture and located in Lisbon.
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Lindström, Per, and Oscar Pap. "Mapping the current state of SSL/TLS." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-138391.
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The focus of this thesis is to analyze cryptographic protocol and algorithm usage based on three different data sets where the largest set contains one million websites. Ciphers, algorithms and different versions of cryptographic protocols are described and discussed. Some of the common attacks that make the ciphers or protocols obsolete are also presented and explained. In order to obtain the data sets and analyze them, a web crawler and a prober program were developed. The results from the analysis show that more popular websites have better security compared to the not so popular ones. The results also show that many broken and insecure ciphers and protocols are still very popular today. The thesis discusses the use of old software as a potential reason for why so many websites support weak protocols and ciphers.
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Armknecht, Jonathan Blake. "A Developer Usability Study of TLS Libraries." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8685.
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Transport Layer Security (TLS) is a secure communication protocol between a client and a server over a network. The TLS protocol provides the two endpoints with confidentiality through symmetric encryption, endpoint authentication using public-key cryptography, and data integrity using a MAC. However, studies show that security vulnerabilities within TLS connections are often caused by developers misusing TLS library APIs. We measure the usability of four TLS libraries by performing a developer user study. Participants were given code that connects to google.com through HTTP, and tasked with using a TLS library to change the code so that it connects securely to Google through HTTPS. Our results help show what makes a library usable and what problems arise for developers using these TLS libraries. We found that the main way to ensure a TLS library is usable is to focus on having clear documentation. From our results, we provide suggestions on how to create usable documentation.
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Georges, George. "Algorithmes de calcul de positions GNSS basés sur les méthodes des moindres carrés avancées." Thesis, Belfort-Montbéliard, 2016. http://www.theses.fr/2016BELF0298/document.
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Dans ce mémoire, une nouvelle approche neuronale TLS EXIN est proposée pour estimer la position d'un récepteurGPS. L'idée générale de cette approche est d'avoir une méthode plus robuste pour le calcul de la position.Le pseudorange alone est l'une des techniques les plus simples et les plus utilisées pour le positionnement GPS.Cette technique nécessite la résolution d'un système surdéterminé d'équations linéaires Ax+/-b. En général, lesmoindres carrés ordinaires (OLS) et les moindres carrés pondérés (WLS) sont les méthodes couramment utiliséespour estimer la position d'un récepteur grâce à leur rapidité et leur robustesse, mais la structure particulière de lamatrice de données A et les bruits affectant ses entrées ne sont pas considérés. Au contraire, cette thèse a pourobjectif d'analyser ces problèmes et d'étudier le comportement des méthodes des moindres carrés (LS) enprésence d'une matrice de données A bruitée.L'approche des moindres carrés totaux (TLS) prend en compte le bruit dans la matrice de données A ainsi que dansle vecteur d'observation b. Cette dernière est une technique moins robuste que OLS et plus sensible auchangement des données, elle est en général résolue par une méthode directe. La méthode TLS EXIN basée surles réseaux de neurones est un algorithme itératif (flux gradient) pour résoudre le problème TLS. Elle donne unmeilleur résultat parce qu'elle peut exploiter les informations d'état initial provenant des époques précédentes et, encas de conditions initiales nulles, donne une estimation précise même en cas de problème singulier.Pour réaliser des comparaisons entre les différentes méthodes des moindres carrés (LS), deux jeux de données ontété collectés. Le premier jeu de données est issu du réseau TERIA et comporte des données collectées depuisdifférentes stations de référence situées dans toute la France. Le deuxième jeu de données est le résultat d'unecampagne de mesures utilisant un appareil GPS (Ublox NL-6002U).Grâce à ces données réelles, un nombre de conditionnement bas a été estimé. Dans ce cas, toutes les méthodesLS donnent des estimations équivalentes, et le choix du meilleur algorithme (OLS, et surtout, WLS) est privilégiépour leur rapidité de calcul. Cependant, le pire scénario qui puisse se produire a été étudié (dans le cas d'unsatellite éloigné), et ont été observés des mauvais conditionnements du problème de GPS (nombre deconditionnement élevé). Cette situation extrême justifie l'utilisation du réseau neuronal TLS EXIN. Les résultatsobtenus confirment cette approche, même pour un nombre de conditionnement élevé.____________________________________________________________________________________________In this thesis, the neural approach TLS EXIN was proposed in a new way in order to estimate the position of a GPSreceiver. The general idea of this approach is to develop a more robust method for calculating the position.The ¿pseudorange alone¿ method is one of the simplest techniques and most widely used for estimating the GPSpositioning and it results in solving an overdetermined system of linear equations Ax¿b. In general, the ordinaryleast squares (OLS) and weighted least squares (WLS) are the commonly used methods to estimate the position ofa receiver for their quickness and robustness, but the particular structure of the data matrix A and the noise affectingits entries are not considered. This thesis, instead, aims to address these problems and study the behavior of leastsquares (LS) methods in the presence of a noisy data matrix A.The approach of total least squares (TLS) takes into account the noise in A and b. It is a less robust technique thanOLS and more sensitive to data changes. It is general solved as a direct method. Instead, the neural network TLSEXIN, which is an iterative algorithm (gradient flow) for solving TLS, works better both because it may exploit theinitial condition information derived from the previous epochs, and, in case of null initial conditions, yields anaccurate estimate even in case of close-to-degenerate data matrix.To perform tests between different methods of least squares, two sets of data were collected. The first one comesfrom the TERIA network and includes data collected from different reference stations located throughout France.While the second one is the result of a measurement campaign using GPS (Ublox NL-6002U).Using the real data, a low condition number has been estimated: in this case all LS methods yield equivalentestimates: as a consequence, OLS and WLS are to be preferred for their low computational cost. However, theworst scenario has been investigated which may occur in case of a distant satellite, resulting in the ill-conditioning ofthe GPS problem. This extreme situation justifies the use of the TLS EXIN neural network. The results obtainedconfirm of this approach even for very large condition numbers
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Zugárek, Adam. "Hardwarově akcelerovaný přenos dat s využitím TLS protokolu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413087.
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This paper describes implementation of the whole cryptographic protocol TLS including control logic and used cryptographic systems. The goal is to implement an application in the FPGA technology, so it could be used in hardware accelerated network card. The reason for this is new supported higher transmission speeds that Ethernet is able to operate on, and the absence of implementation of this protocol on FPGA. In the first half of this paper is described theory of cryptography followed by description of TLS protocol, its development, structure and operating workflow. The second half describes the implementation on the chosen technology that is also described here. It is used already existing solutions of given cryptographic systems for the implementation, or at least their parts that are modified if needed for TLS. It was implemented just several parts of whole protocol, such are RSA, Diffie-Hellman, SHA and part of AES. Based on these implementations and continuing studying in this matter it was made conclusion, that FPGA technology is inappropriate for implementation of TLS protocol and its control logic. Recommendation was also made to use FPGA only for making calculations of given cryptographic systems that are controlled by control logic from software implemented on standard processors.
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Hutar, Jan. "Detekce a analýza přenosů využívajících protokoly SSL/TLS." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-317032.
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This diploma thesis deals with a detection and analysis of secure connections of electro- nic communication through SSL/TLS protocols. The thesis begins with introduction to SSL/TLS protocols. Thereafter, an analysis of messages used to establish secure con- nections using STARTTLS and postal protocols SMTP, POP3, and IMAP was made. Metadata detection and extraction of secured simplex and duplex connections take place using deep packet inspection tools. The tool of choice is the nDPI library from the Ntop project. The library was extended to detect the connections and extract the metadata based on studies and analysis of transmitted messages. Finally, testing is performed on a training data set and a basic analysis of acquired metadata is made.
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Duraes, Fernanda do Valle. "O papel dos receptores do tipo Toll (TLRs) na infecção pelo Schistosoma mansoni." Universidade Federal de Minas Gerais, 2010. http://hdl.handle.net/1843/UCSD-85EQ3N.
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ABSTRACTSchistosomiais is a chronic helminthic infection and remains as an important morbidity factor in tropical endemic areas such as Brazil. Toll-like receptors (TLRs) play an important role in the innate recognition of pathogens by Dendritic cells (DCs) and in the induction of immune responses. Although it is clear that TLR2, TLR3 and TLR4 can recognize different Schistosoma components in vitro, little is known regarding the role of these receptors in vivo. To characterize the innate immune response during Schistosoma infection, WT (C57BL/6) and MyD88-, TLR2- and TLR4 deficient mice were infected with 30 cercariae. Parasitological parameters, such as the number of worms recovered and the number of eggs in the liver, as well as pathological and immunological parameters were evaluated. Even though the differences between WT and KO mice in terms of worm burden were not significant, TLR2 KO mice displayed reduced fecundity, resulting is less eggs trapped in the liver. However, major differences were seen regarding host immune responses. The lack of MyD88 and TLR2 resulted in smaller granulomas followed by reduced production of CCL11 in the hepatic tissue of these mice. Furthermore, cells from infected MyD88 KO mice also produced significantly less IL-5 than their WT controls, both in the liver tissue and in spleen cells upon restimulation with Schistosoma egg antigen (SEA), indicating diminished Th2 response. Further, Schistosoma mansoni larvae is the first and the most susceptible parasite life stage to interact with the host immune system. Therefore, the role of the innate immune system was evaluated in an in vitro model of DC activation by schistosomula tegument (Smteg). Smteg was able to activate DCs to produce IL-12p40, TNF- and also to up-regulate the co-stimulatory molecules CD40 and CD86. Moreover, using DCs derived from MyD88-, TLR2- and TLR4 deficient mice we have shown that the ability of Smteg to activate DCs in vitro involves MyD88 signaling pathways and TLR4/Smteg interaction. Together, these data indicate that the innate immune system is involved in the initial recognition of Schistosoma components both in vitro and in vivo. These interactions play an important role in dictating the outcome of pathological and immunological changes resulting from the infection.RESUMOA esquistossomose é o resultado de uma infecção helmíntica crônica e permanece como importante fator de morbidade em áreas endêmicas tropicais, incluindo o Brasil. Os receptores do tipo toll (TLRs) têm um importante papel no reconhecimento imune inato de patógenos por células dendríticas (DCs) e na indução das respostas adaptativas subseqüentes. Embora já tenha sido demonstrado que TLR2, TLR3 e TLR4 sejam capazes de reconhecer diferentes componentes do Schistosoma in vitro, pouco se sabe sobre o papel desses receptores in vivo. Para a caracterização da resposta imune inata durante a infecção pelo Schistosoma, camundongos selvagens (C57BL/6) e deficientes em MyD88, TLR2 e TLR4 foram infectados com 30 cercárias. Parâmetros parasitológicos como o número de vermes e de ovos no fígado, bem como patológicos - área do granuloma e de fibrose - e imunológicos foram avaliados. Apesar de não terem sido observadas diferenças com relação ao número total de vermes recuperados entre os grupos, os animais TLR2 KO apresentaram uma reduzida fecundidade, com consequente redução do número de ovos depositados no fígado. Entretanto, as maiores alterações foram vistas com relação à resposta imune do hospedeiro. A ausência de MyD88 e de TLR2 resultou em granulomas menores acompanhados da menor produção de CCL11 no tecido hepático desses animais. Além disso, a produção de IL-5 tanto no tecido hepático quanto em esplenócitos de animais MyD88 KO quando re-estimulados com SEA in vitro, estava diminuída, indicando uma redução na resposta Th2. O esquistossômulo é o estágio de vida do Schistosoma mais susceptível ao ataque pelo sistema imune do hospedeiro. Portanto, o papel da resposta imune inata in vitro, num modelo de ativação de células dendríticas pelo tegumento do esquistossômulo (Smteg) foi avaliado. O Smteg foi capaz de ativar as DCs para produzir IL-12 e TNF- e também para aumentar a expressão das moléculas co-estimuladoras CD40 e CD86. Além disso, utilizando DCs derivadas de camundongos deficientes em MyD88, TLR2 e TLR4 nós demonstramos que a habilidade das DCs em produzir IL-12 e TNF- envolve a interação entre o Smteg/ TLR4 e a via de sinalização dependente de MyD88. Em conjunto, esses resultados indicam que o sistema imune inato participa do reconhecimento inicial de componentes do Schistosoma tanto in vitro quanto in vivo. Esse reconhecimento influencia as mudanças patológicas e imunológicas decorrentes da infecção.
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Svensson, Pär. "Upgrading the SSL protocol to TLS in the Roxen WebServer." Thesis, Linköping University, Department of Electrical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1475.
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The company Roxen Internet Software have an implementation of the secure network protocol SSL (Secure Sockets Layer) which is used in their web server product. This report describes the upgrading of that implementation to the TLS1.0 (Transport Layer Security) standard. It also describes a performance investigation of the SSL/TLS support in the Roxen WebServer and compares it with other common web servers. The initial setup time for the secure SSL/TLS connection was found to be very long in the Roxen Webserver compared to its competitors. The main bottleneck, in the Roxen implementation, was found to be the modular exponentiation that is the core of the RSA decryption algorithm. One suggested improvement is to upgrade the bignumber numerical package used in Roxen WebServer, GMP (The GNU Multiple Precision arithmetic library) from version 2.0 to version 4.0. The newer version of the bignumber package have been measured to have considerably better performance in its modular exponentation operation.
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Walsby, Elisabeth Jane. "Role of FUS (TLS) in differentiation in acute myeloid leukaemia." Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/55540/.
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Leukaemia is the result of molecular abnormalities which lead to a block in differentiation that is the defining characteristic of myeloid leukaemia cells. Work to identify the genes that are associated with this defective differentiation led to the identification of the involvement of the FUS gene. FUS (TLS) is a housekeeping gene that is capable of binding DNA and RNA. FUS has roles in coupling mRNA transcription and processing and in the repair of double stranded DNA breaks. Previous work within this department has shown that FUS is down-regulated in human leukaemia cell lines in response to induction of differentiation with ATRA and that FUS is up-regulated in acute myeloid leukaemia (AML) patients. The aim of this study was to identify whether this is a causative or correlative relationship and also to identify target genes associated with FUS dysregulation. Transduction of human (HL- 60, NB4, NB4R2) and murine (32D, 32D AML-ETO, 32D B2A2) leukaemia cell lines with retroviral constructs expressing FUS or antisense FUS resulted in some over-expression or down-regulation of FUS in these cells. The effect of FUS modulation in the transduced cell lines was assessed through cell growth and viability. No effect on the growth and viability of transduced cells was observed as a result of FUS modulation. To determine whether FUS had a role in differentiation, the transduced cell lines were induced to differentiate using ATRA and G-CSF. Differentiation was assessed by measurement of cell growth, viability and the expression of cell surface markers by flow cytometry. The result of expression of FUS antisense in the ATRA sensitive NB4 and 32D cell lines was to generate resistance to differentiation induction using ATRA. Conversely in the ATRA resistant NB4R2 and 32D B2A2 cells, expression of FUS antisense reinstated the ability to differentiate in these cells. In response to treatment with G-CSF, the 32D cells expressing FUS antisense developed a resistance to differentiation while the previously G-CSF resistant 32D B2A2 cells became capable of differentiation when FUS antisense was expressed in these cells. Following the demonstration of an altered phenotype in response to treatment with different differentiation inducers in cells containing FUS antisense constructs, genes acting as target genes of FUS were identified using the Affymetrix gene expression system. The effect of FUS over-expression and down- regulation were studied in all the murine 32D derived cell lines and in the human NB4 cell line. In addition to this, gene expression changes resulting from FUS modulation in the NB4 cells during treatment with ATRA over 96 hours was investigated in this manner. Expression levels of genes associated with FUS dysregulation were verified using quantitative RT-PCR. Genes identified as having altered expression as a result of the expression of the FUS antisense construct included transcription factors, genes involved in apoptosis and differentiation and genes that have previously been shown to interact with, or have homology to, FUS itself. Further analysis of these candidate genes suggested that they were not likely to have a dominant effect in the altered phenotype seen in the transduced cells but were more likely to play a participatory role in the effects observed. This study has concluded that FUS may have a role in haematopoietic differentiation induced by both ATRA and G-CSF but this role appears to be context dependent making it important to study the effects of its modulation in primary AML blasts. The mechanism through which FUS affects the ability of the cells to differentiate remains unresolved.
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Fell, Sérgio George Silva. "Avaliação do desempenho do TLS nas comunicações aeronáuticas via satélite." Instituto Tecnológico de Aeronáutica, 2004. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=623.
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TLS (Transport Layer Security), protocolo de segurança que opera acima do TCP/IP e abaixo das aplicações de alto nível, é um protocolo amplamente utilizado e aceito na World Wide Web para fornecer privacidade, integridade e autenticidade dos dados. Para a realização de aplicações a bordo de aeronaves, tais como, e-commerce e transações financeiras, o uso do TLS é bastante recomendado. No entanto, o desempenho deste protocolo nas redes de dados aeronáuticas poderá ser degradado se o protocolo TCP não for alterado, pois o mesmo não consegue distinguir entre as perdas causadas pelos erros de transmissão no canal daquelas devido a congestionamento. Este trabalho propõe mudanças no TCP que visam melhorar seu desempenho em ambientes sem fio, tipicamente das redes aeronáuticas, e analisa o desempenho do TLS na presença deste TCP modificado.
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Käck, Emil. "TLS Decryption in passive monitoring system with server private key." Thesis, Umeå universitet, Institutionen för datavetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184490.
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Many network operators need to be able to ensure that customers get the level of service they pay for. To avoid bandwidth and server performance bottlenecks, and easily troubleshoot network problems, the network providers need to be able to see what payload data is sent. Modern networks encrypt data when sending it between nodes that makes passive monitoring more complex. A prevalent encryption mechanism on an IP-based network is TLS that needs to be decrypted. This article’s purpose is to check if it is possible to decrypt TLS traffic in a passive monitoring system with the server’s private key. This is done by implementing a decryptor in a passive monitoring system in the programming language Java. The implemented solution intercepts the traffic, takes out relevant data from the traffic, and derives the session key from that data. How this is done is dependent on what cipher suite is used for the session. Because of delimitations and lack of time the solution is only able to decrypt the cipher suite TLS_RSA_WITH_AES_128_CBC_SHA256. The result showed that it is possible to decrypt TLS traffic and should be possible for more than the specified cipher suite. But there exists a major problem that's called forward secrecy. This is used in the key exchange algorithm called Diffie–Hellman and makes it impossible to decrypt with only server private key. The conclusion is that it is possible but because of forward secrecy, it is not recommended. TLS 1.3 only uses cipher suites with the key exchange algorithm Diffie–Hellman and the forward secrecy functionality is important for security.
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Silva, Leandro Gustavo da. "Papel dos receptores do tipo Toll (TLRs) na imunopatogênese da malária associada à gravidez." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42135/tde-21032012-160144/.
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A malária asociada à gavidez pode gerar complicações para a mãe e para o feto. Receptores do tipo Toll (TLR) TLR2, TLR4 e TLR9, podem reconhecer componentes do Plasmódio. Estes receptores sinalizam via proteína MyD88. Contudo existem poucos dados sobre os TLR na malária placentária. Assim, o objetivo desse trabalho foi estudar o papel dos TLR2, 4, 9 e da MyD88 na malária placentária. Dentre fêmeas C57BL/6, TLR2-/-, TLR9-/- e MyD88-/-, a linhagem MyD88-/- apresentou maiores níveis de parasitemia, sobrevivência e cuidado parental, e ainda placentas de fêmeas MyD88-/- infectadas, ao contrario das TLR2-/- e TLR9-/-, não tiveram diminuição do espaço vascular em relação aos controles. Animais C57BL/6 infectados apresentaram aumento do mRNA de IL1-b e IL-6 na placenta, o que não ocorreu nos MyD88-/-. Gestantes C57BL/6 e MyD88-/- infectadas tiveram mais esplenócitos, com expansão preferencial de linfócitos B (CD19+). Também foi evidenciado nos animais C57BL/6 infectados um aumento da expressão do marcador de ativação CD69 nos linfócitos TCD8+. Em conjunto, estes resultados sugerem que a sinalização via MyD88 é importante para o desenvolvimento da malária placentaria e esta pode estar relacionada com a resposta inflamatória exacerbada induzida pelo parasita.Pregnancy associated malaria can lead to complications both for the mother and the fetus. Toll like receptors (TLR) TLR2, TLR4 and TLR9 can recognize components of the Plasmodium sp. These receptors signal through the MyD88 protein. However there are few data on TLR in placental malaria. Thus, The objective of this work was to study the role of TLR2, 4, 9 and MyD88 in placental malaria. Among female mice C57BL/6, TLR2-/-, TLR9-/- and MyD88-/-, the lineage MyD88-/- showed higher levels of parasitemia, survival and parental care, and still placentas of MyD88-/- infected female, differently of TLR2-/- and TLR9-/-, had no decrease in the vascular space compared to controls. Animals C57BL/6 infected showed increased mRNA for IL1-b and IL-6 in the placenta, which did not occur in MyD88-/-. Pregnant infected C57BL/6 and MyD88-/- had more splenocytes, with preferential expansion of B lymphocytes (CD19+). in infected C57BL/6 was also demonstrated an increased expression of the activation marker CD69 on CD8+ T lymphocytes. Together, these results suggest that signaling through MyD88 is important for the development of placental malaria and this may be related with an increased inflammatory response induced by the parasite.
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Unurkhaan, Esbold. "Secure end-to-end transport over SCTP a new security extension for SCTP /." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975686569.
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Silva, Fernanda Abujamra da. "Associação da aterosclerose com polimorfismo de TLR2, TLR4, TNF-α e IL-6 e suas expressões em pacientes diabéticos tipo 2." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-23042010-083813/.
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O Diabete tipo 2 é uma síndrome heterogênea caracterizada por resistência à insulina e /ou diminuição relativa da função secretora das células β pancreáticas. Os Diabéticos têm risco maior de desenvolver aterosclerose, que é uma doença inflamatória crônica que envolve a resposta imune. Os TLRs sinalizadores da resposta imune inata que ativam vias que participam na regulação da inflamação podem estar associados com a patogênese da aterosclerose. Além disso, são capazes de induzir a resistência à insulina. Estudos sugerem que a inflamação é um fator chave na aterogênese em diabéticos tipo 2. Citocinas pró-inflamatórias, como a IL-6 e o TNF-α, são produzidas pelo tecido adiposo em grande quantidade em indivíduos obesos, especialmente em pacientes com DM2. Este estudo tem por objetivo avaliar a associação dos genes do TLR2, TLR4, TNF-α e IL-6 com o diabetes tipo 2 e com a aterosclerose. Foram selecionados sessenta e um indivíduos DM2 e trinta e nove indivíduos normoglicêrmicos (grupo controle) na seção de Coronárias do Instituto Dante Pazzanese de Cardiologia (São Paulo, Brasil). O ultra-som de carótida foi utilizado para avaliar a presença de aterosclerose. Os polimorfismos dos genes TLR4 (Thr399lle), TLR2 (Arg753Gln), and IL6 (-174G>C) foram identificados pela PCR-RFLP. O polimorfismo dos genes TLR4 (Asp299Gly) and TNF-α (-308G>A) foram detectados por HRM. A expressão do mRNA nos leucócitos do sangue periférico foi mensurado pela PCR em tempo real utilizando o gene GAPD como gene referência. No grupo diabéticos, indivíduos portadores do alelo IL-6 -174C apresentaram colesterol total, VLDL-C e triglicérides que os portadores do genótipo GG (respectivamente, p=0,007, p=0,006 e p= 0,030). A expressão de TLR4 foi maior em indivíduos do grupo diabéticos que no grupo controle (p=0,029). Em DM2, o genótipo TNF-α -308GG foi associado com o aumento da expressão do mRNA do gene TNF-α (p=0,031) e maiores concentrações de fibrinogênio que os portadores do alelo -308A (genótipo GA+AA) (p=0,020). Em indivíduos com aterosclerose o alelo TLR4 299Gly foi associado com altas concentrações de glicemia pós 75g de glicose (p=0,012). E portadores do alelo IL6 -174C apresentaram maiores concentrações de colesterol total e LDL-C que nos portadores do genótipo GG (ambos p<0,001). O polimorfismo -174G>C (alelo C) e o DM2 mostraram serem fatores de risco para a aterosclerose (odds ratio respectivamente: 3,0 and 16,962). E, o sexo masculino e a menopausa mostraram serem fatores de risco para o DM2.Type 2 diabetes is an heterogeneous syndrome characterized by the resistance to insulin and/or relative decrease of the secretion of insulin of the pancreatic β cells. T2DM are in high risk of develop atherosclerosis, that is a chronic inflammatory disease involving immune response. Many existing in the atherosclerotics plaques the TLRs are signaling for immune innate response, that activate inflammatory cells involved in progression of atherosclerotic disease. TLRs can be also associated with induction of the resistance to insulin. Many studies have been suggesting that inflammation is a key factor of the progression of atherosclerotic disease in type 2 diabetes. Proinflammatory cytokines, such as IL-6 and TNF-α, are produced by the adipose tissue in high concentration in obese individuals, mainly among patients with T2DM. This study aims to investigate the relationship between TLR2, TLR4, TNF-α and IL-6 gene expression and polymorphisms with T2DM and atherosclerosis. Sixty-one T2DM and thirty nine normoglycemic (control group) individuals were selected at the Coronary Session of the Instituto Dante Pazzanese de Cardiologia (Sao Paulo, Brazil). Carotid artery ultrassonography was used to evaluate the atherosclerotic status. Polymorphisms of TLR4 (Thr399lle), TLR2 (Arg753Gln), and IL6 (-174G>C) genes were detected by PCR-RFLP. TLR4 (Asp299Gly) and TNFA (-308G>A) gene polymorphisms were detected by HRM. Blood leukocytes mRNA expression was measured by real time PCR using GAPD as a reference gene. In T2DM, individuals carrying IL6 -174C allele had higher total cholesterol, VLDL-c and triglycerides than the genotype GG carriers (respectively, p=0,007, p=0,006 and p= 0,030). TLR4 mRNA expression was higher in T2DM than in control individuals (p=0,029). In T2DM group, TNF-α -308GG genotype was associated with increased TNF-α mRNA expression levels (p=0,031) and higher fibrinogen levels than those carrying -308A allele (GA+AA genotypes) (p=0,020). In individuals with atherosclerosis TLR4 299Gly allele was associated with high post-test glucose levels (p=0,012). And carrying IL6 -174C allele had higher total cholesterol and LDL-C than the genotype GG carriers (both p<0,001). The polymorphism -174G>C and the T2DM was related with risk for atherosclerosis (odds ratio respectively: 3,0 and 16,962) and, the male sex and menopause was related with risk for T2DM (odds ratio respectively: 3,401 and 3,025).
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Vignudelli, Andrea. "Filtraggio e censura dei servizi Internet Un'analisi sul protocollo SSL/TLS." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13204/.
Full textAbstract:
Obiettivo ultimo di questa tesi è fornire le competenze necessarie per poter capire come effettuare politiche di filtraggio dei contenuti fruibili su Internet in contesti prevalentemente di network locali come LAN aziendali ma anche su scala maggiore, effettuando politiche di blocco al livello logico 7 della pila protocollare ISO/OSI.
Nello specifico verranno approfondite le specifiche tecniche del protocollo SSL/TLS e su queste basi teoriche verranno implementate e testate regole di blocco di specifici servizi Internet simulando il contesto di una piccola rete domestica con un Firewall di frontiera posto davanti al gateway della rete locale che funge da filtro per la comunicazione con la rete Internet.
Verranno inoltre esposte delle problematiche direttamente correlate a quella che è l'infrastruttura giuridica fisicamente costruita intorno all'accertamento dell'identità digitale degli enti/soggetti all'interno di comunicazioni che sfruttano le funzionalità del protocollo SSL/TLS come strumento per criptare i dati ed avere garanzia sull'identità che si cela sul lato Server della comunicazione, trattando nello specifico alcuni casi storici di brecce informatiche all'interno delle infrastrutture fisiche dei Certificate Authorities, enti predisposti al ruolo di certificatori delle identità digitali sopracitate, o dell'uso improprio da parte loro del potere conferitogli, saranno inoltre esposti e replicati su scala minore esempi di come alcuni enti governativi nazionali sfruttano alcune caratteristiche intrinseche di questo protocollo per bloccare determinati servizi all'interno della sottorete Internet da loro gestita e di come in un contesto storico nel quale venisse a mancare il caposaldo della Network Neutrality, proprio quelle specifiche protocollari potrebbero essere utilizzate per effettuare politiche di gestione prioritaria nell'instradamento dei pacchetti all'interno della rete Internet.
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Petersson, Jakob. "Analysis of Methods for Chained Connections with Mutual Authentication Using TLS." Thesis, Linköpings universitet, Informationskodning, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119455.
Full textAbstract:
TLS is a vital protocol used to secure communication over networks and it provides an end- to-end encrypted channel between two directly communicating parties. In certain situations it is not possible, or desirable, to establish direct connections from a client to a server, as for example when connecting to a server located on a secure network behind a gateway. In these cases chained connections are required. Mutual authentication and end-to-end encryption are important capabilities in a high assur- ance environment. These are provided by TLS, but there are no known solutions for chained connections. This thesis explores multiple methods that provides the functionality for chained connec- tions using TLS in a high assurance environment with trusted servers and a public key in- frastructure. A number of methods are formally described and analysed according to multi- ple criteria reflecting both functionality and security requirements. Furthermore, the most promising method is implemented and tested in order to verify that the method is viable in a real-life environment. The proposed solution modifies the TLS protocol through the use of an extension which allows for the distinction between direct and chained connections. The extension which also allows for specifying the structure of chained connections is used in the implementation of a method that creates chained connections by layering TLS connections inside each other. Testing demonstrates that the overhead of the method is negligible and that the method is a viable solution for creating chained connections with mutual authentication using TLS.
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Reimers, Erik. "On the security of TLS and IPsec : Mitigation through physical constraints." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119357.
Full textAbstract:
TLS and IPsec are two protocols that provide secure communication on the Internet. They provide similar services but operate on different levels. This report compiles some of thecurrent known vulnerabilities that exist in those two protocols. It also describes attacks that exploit those vulnerabilities. Based on the vulnerabilities this paper gives guidelines onhow to avoid them when implementing TLS and IPsec. This paper also demonstrates a proof-of-concept that shows how IPsec can be configured to avoid some of the vulnerabilities. Theproof-of-concept also shows how IPsec can be used to setup a secure connection between two peers, using Near Field Communication, on an ad hoc network.
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Cedergren, Lucas, and Richard Paakkonen. "En jämförelse mellan TLS och UAV-fotogrammetri : Inmätning av hårdgjorda ytor." Thesis, Uppsala universitet, Byggteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-257679.
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At present day there are several different methods for measuring of paved surfaces. The most common methods today are measuring with a total station, the Global Navigation Satellite System (GNSS) and terrestrial laser scanning (TLS). Recently the development of unmanned aerial vehicles, known as drones, has increased exponentially and today there are several ways of using drones for measuring surfaces by photographing and laser scanning. This thesis contains a comparison between the methods terrestrial laser scanning (TLS), and unmanned aerial vehicle photogrammetry (UAV). The measurements have been applied on two different test surfaces, one of asphalt and one of gravel. The purpose of the comparison is to investigate whether the airborne photogrammetry is equivalent accurate in its height levels as the terrestrial laser scanning. For the comparison to be more extensive, these two methods have not only been compared in precision but also in the areas of ease of use and economy. The precision was analyzed by comparing the height levels in randomly placed control points on the test surfaces. This has been made possible by the creation of terrain models of test surfaces in the software Geo where a surface scan of the models have been implemented. With the help of surface control the height deviations in the control points have been calculated and from these deviations the precision of the airborne photogrammetry has been evaluated. The ease of use has been analyzed based on observations made and information gathered from experienced consultants for each technology. For the economic aspect the costs for each measurement method has been presented to get an overall picture of each measurement method costs. The work has been carried out on behalf of the consulting firm Bjerking AB. The goal is to be able to provide Bjerking with a recommendation for which technology is best suited for measuring of paved surfaces. The results of the survey show that the UAV varies by a mean of 11 mm on the surface of gravel and 2 mm on the surface of the asphalt. The final recommendation given is that the UAV is preferred for measurement of asphalt roads, because since the precision is equivalent to TLS, the method is safe
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McVeety, Sam. "Secure channel establishment in disadvantaged networks : TLS optimization using intercepting proxies." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/61301.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 65-66).
Transport Layer Security (TLS) is a secure communication protocol that is used in many secure electronic applications. In order to establish a TLS connection, a client and server engage in a handshake, which usually involves the transmission of digital certificates. In this thesis we develop a practical speedup of TLS handshakes over bandwidth-constrained, high-latency (i.e. disadvantaged) links by reducing the communication overhead associated with the transmission of digital certificates. This speedup is achieved by deploying two specialized TLS proxies across such links. Working in tandem, one proxy will replace certificate data in packets being sent across the disadvantaged link with a short reference, while the proxy on the other side of the link will restore the certificate data in the packet. The certificate data will be supplied by local or remote caches. Our solution preserves the end-to-end security of TLS and is designed to be transparent to third-party applications, and will thus facilitate rapid deployment by removing the need to modify existing installations of TLS clients and TLS servers. Testing shows that this technique can reduce the overall bandwidth used during a handshake by over 50%, and can reduce the time required to establish a secure channel by over 40% across Iridium links.
by Sam McVeety.
M.Eng.
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Gunke, Andreas, and Sven Jany. "Ableitung eines Bergmännischen Risswerks, korreliert aus ALS-, TLS- und RGB-Daten." Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2018. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-237304.
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Neben den herkömmlichen Messverfahren etablieren sich das Airborne sowie das Terrestrische Laserscanning in der Vermessung mit steigender Tendenz. Diese Verfahren werden überall dort angewendet, wo komplexe Objekte berührungslos und vollflächig erfasst werden sollen.
In diesem Beitrag soll die Ableitung eines Bergmännischen Risswerks mittels korrelierter Daten des terrestrischen Laserscannings sowie des Airborne Laserscannings am Beispiel der Kalihalde Neuhof-Ellers dargestellt werden. Das Unternehmen K+S KALI GmbH ist für die markscheiderische Führung eines Bergmännischen Risswerks nach dem Bundesberggesetz und der Markscheider-Bergverordnung verantwortlich.
Die Halde wurde dreidimensional aufgenommen. Die ALS-Daten werden mit den TLS-Daten verknüpft. Eine Kombination von Laseraufnahmen und Fotos ermöglicht es, die Ist-Situation realistisch darzustellen. Das Produkt ist ein 3D-CAD-Modell (DHM).
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Le, Corf Katy. "La dualité fonctionnelle de la protéine MyD88, dans la signalisation Ras/MAPKs et l'inflammation, conduit à la transformation cellulaire." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10121.
Full textAbstract:
MyD88 est une protéine adaptatrice du système immunitaire inné, impliquée dans la défense de l’organisme contre les agents microbiens. Elle est recrutée aux « Toll-like receptors » (TLRs) suite à la reconnaissance par ces derniers de motifs microbiens conservés, les PAMPs (Pathogens-associated molecular patterns). La voie de signalisation ainsi déclenchée va aboutir à la production de cytokines pro-inflammatoires, de chimiokines et d’espèces actives de l’oxygène. De cette façon, les TLRs, via MyD88, constituent la première ligne de défense contre les pathogènes.De nombreuses études ont permis de démontrer que MyD88 est nécessaire pour la réponse inflammatoire, qui promeut la carcinogenèse. Dans le cadre d’une étude sur les TLRs et le cancer, l’équipe a démontré, grâce à une étude in vivo, que MyD88 participe au processus de tumorigenèse médiée par l’oncogène ras et est nécessaire à l’activation de la voie canonique des MAPKs, ainsi qu’à la transformation cellulaire in vitro. Nous avons ensuite déterminé le mécanisme par lequel MyD88 intervient dans la voie de signalisation Ras/MAPKs, en permettant le maintien de l’activation de cette voie. En effet, MyD88 interagit avec une MAPK clé de cette voie : la kinase ERK, et protège cette dernière de sa déphosphorylation par sa phosphatase spécifique MKP-3, MyD88 et MKP-3 se liant à ERK par le même domaine. Nous avons démontré la pertinence de ce mécanisme, grâce à la mise en évidence d’une surexpression de la protéine MyD88 et de son interaction avec la forme phosphorylée d’ERK dans des coupes de tissus tumoraux humains (estomac, poumon, colon).L’ensemble des résultats obtenus au cours de ma thèse ont permis de montrer qu’en plus de son rôle bien défini en tant qu’adaptateur des récepteurs de l’immunité innée dans les processus inflammatoires, MyD88 joue un rôle direct, qui semble être crucial dans la signalisation Ras, le contrôle du cycle cellulaire et la transformation cellulaireMyD88 is an adaptator protein of the innate immune system, implicated in the défense against microbes. MyD88 is recruited by the Toll-Like Receptors (TLRs) upon there interaction with conserved microbial patterns (PAMPs). Therefore, TLR signaling pathway induces the production of pro-inflammatory cytokines, chemokines and reactive oxygen species. TLRs, via MyD88, form the first line of defense against pathogens. Accumulating evidence points to inflammation as a promoter of carcinogenesis. MyD88 is an adaptor molecule in TLR and IL-1R signaling that was recently implicated in tumorigenesis through proinflammatory mechanisms. Here we have shown that MyD88 is also required in a cell-autonomous fashion for Ras-mediated carcinogenesis in mice in vivo and for MAPK activation and transformation in vitro. Mechanistically, MyD88 bound to the key MAPK, ERK, and prevented its inactivation by its phosphatase, MKP3, thereby amplifying the activation of the canonical Ras pathway. The relevance of this mechanism to human neoplasia was suggested by the finding that MyD88 was overexpressed and interacted with activated ERK in primary human cancer tissues. Collectively, these results show that in addition to its role in inflammation, MyD88 plays what we believe to be a crucial direct role in Ras signaling, cell-cycle control, and cell transformation
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Ihaddadene, Mohand Ameziane. "Numerical modeling of streamer discharges in preparation of the TARANIS space mission." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2040/document.
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Les sprites sont de gigantesques phénomènes lumineux qui sont produits entre 40 et 90 km d’altitude généralement par des éclairs nuage-sol positifs. Les sprites sont des phénomènes très brefs (durée de quelques millisecondes) qui appartiennent à la famille des TLEs (évènements lumineux transitoires) et qui sont composés de structures filamentaires nommées streamers. Les streamers sont des filaments de plasma, qui se propagent à des vitesses allant jusqu’à ∼10⁷ m/s et qui possèdent des champs électriques très forts souvent proches de 150 kV/cm (champs réduit à la pression atmosphérique). Lors de ce travail, on a développé un modèle fluide de plasma qui simule les décharges streamers couplées avec un modèle simulant les émissions optiques afin d’étudier la physique des streamers, des TLEs et plus particulièrement des sprites dans le cadre de la mission spatiale TARANIS. Cette mission a pour objectif d’étudier le système Atmosphère-Ionosphère-Magnétosphère, et observera les TLEs et leurs émissions associées: électromagnétiques, optiques, et probablement radiations énergétiques depuis le nadir. Dans cette thèse, on propose d’étudier certains problèmes liés aux streamers et aux sprites qui sont cruciaux pour préparer la mission TARANIS. Plus particulièrement nous abordons certains mécanismes de production de radiations énergétiques par les streamers récemment proposés dans la littérature et nous développons une méthode qui permet de déterminer l’altitude, la vitesse et le champ électrique des streamers des sprites, à partir d’une analyse spectroscopique de leurs émissions optiques. Nos résultats renforceront donc le retour scientifique des futures missions spatiales observant les TLE depuis le nadir et particulièrement TARANISSprites are large optical phenomena usually produced between 40 and 90 km altitude generally by positive cloud-to-ground lightning (+CG). These are short lifetime phenomena (duration of few milliseconds) that belong to the family of transient luminous events (TLEs) and composed of complex filamentary structures called streamers. Streamers are non-thermal plasma filament, highly collisional, propagating with velocities up to 10⁷ m/s, and characterized with high electric fields at their heads often close to 150 kV/cm when scaled to ground level air. In this work, we have developed a streamer plasma fluid model coupled with an optical emission model to investigate the physics of streamers and sprites in the framework of the TARANIS space mission. TARANIS will observe TLEs from a nadir-viewing geometry along with their related emissions (electromagnetic and particles). In this dissertation, we investigate some mechanisms of emission of energetic radiation from streamers recently proposed in the literature and we present an original spectroscopic method to determine sprite streamers altitudes, velocities, and electric fields through their optical emissions. This method is especially useful for increasing the scientific return of space missions that have adopted nadir-based observation strategies
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FILIO, AGUILAR PEDRO DAVID 481858, and AGUILAR PEDRO DAVID FILIO. "Propuesta de inclusión del criptosistema triple des 96en ssl/tls record protocol." Tesis de maestría, Universidad Autónoma del Estado de México, 2014. http://hdl.handle.net/20.500.11799/49976.
Full textAbstract:
TESIS DE INVESTIGACIÓN CIENTIFICA EL PRESENTE TRABAJO DE INVESTIGACIÓN SE CENTRA EN EL SSL/TLS RECORD PROTOCOL DONDE SE CONSTRUYE LA INCLUSIÓN DE TRIPLE DES 96 EN LA MENCIONADA SUITE DE CIFRADODebido a la seguridad requerida al momento de intercambiar información delicada a través de internet, es necesario el uso de algoritmos y protocolos criptográficos complejos como es el caso de Secure Sockets Layer y Transport Layer Security (SSL/TLS), el funcionamiento de éste está dividido en cuatro sub protocolos; Handshake Protocol, Change Cipher Spec Protocol, Alert Protocol y Record Protocol. El presente trabajo de investigación se centra en el SSL/TLS Record Protocol, donde se construye la inclusión del algoritmo Triple DES-96 en la suite de cifrado de SSL/TLS. Con este objetivo, se desarrollan en lenguaje de programación Java los algoritmos Triple DES y Triple DES-96, se realizan pruebas de cifrado y descifrado sobre 1000 archivos de diferentes tipos y tamaños, se mide el tiempo de cada algoritmo en cifrar y descifrar la información, se registran todos los resultados experimentales obtenidos y por último se comparan los resultados. Al descubrir que los resultados son favorables, en disminución de tiempo y mayor robustez en el cifrado, se plantea la inclusión del algoritmo Triple DES-96 en la suite de cifrado SSL/TLS Record Protocol.
CONACYT
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Sama, Reddy Ranjith Kumar. "FUS/TLS in Stress Response - Implications for Amyotrophic Lateral Sclerosis: A Dissertation." eScholarship@UMMS, 2014. http://escholarship.umassmed.edu/gsbs_diss/704.
Full textAbstract:
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease is a fatal neurodegenerative disease. ALS is typically adult onset and is characterized by rapidly progressive loss of both upper and lower motor neurons that leads to death usually within 3-5 years. About 90% of all the cases are sporadic with no family history while the remaining 10% are familial cases with mutations in several genes including SOD1, FUS/TLS, TDP43 and C9ORF72.
FUS/TLS (Fused in Sarcoma/Translocated in Liposarcoma or FUS) is an RNA/DNA binding protein that is involved in multiple cellular functions including DNA damage repair, transcription, mRNA splicing, RNA transport and stress response. More than 40 mutations have now been identified in FUS that account for about 5% of all the familial cases of ALS. However, the exact mechanism by which FUS causes ALS is unknown. While significant progress has been made in understanding the disease mechanism and identifying therapeutic strategies, several questions still remain largely unknown. The work presented here aims at understanding the normal functions of FUS as well as the pathogenic mechanisms by which it leads to disease.
Several studies showed the association of mutant-FUS with structures made up of RNA and proteins, called stress granules that form under various stress conditions. However, little is known about the role of endogenous FUS under stress conditions. I have shown that under hyperosmolar conditions, the predominantly nuclear FUS translocates into the cytoplasm and incorporates into stress granules. The response is specific to hyperosmolar stress because FUS remains nuclear under other stress conditions tested, such as oxidative stress, ER stress and heat shock. The response of FUS is rapid, and cells with reduced FUS levels are susceptible to the hyperosmolar stress, indicating a pro-survival role for FUS. In addition to investigating the functions of endogenous wild-type (WT) FUS, the work presented also focuses on identifying the pathogenic mechanism(s) of FUS variants. Using various biochemical techniques, I have shown that ALS-causing FUS variants are misfolded compared to the WT protein. Furthermore, in a squid axoplasm based vesicle motility assay, the FUS variants inhibit fast axonal transport (FAT) in a p38 MAPK dependent manner, indicating a role for the kinase in mutant-FUS mediated disease pathogenesis. Analysis of human ALS patient samples indicates higher levels of total and phospho p38, supporting the notion that aberrant regulation of p38 MAPK is involved in ALS.
The results presented in this dissertation 1) support a novel prosurvival role for FUS under hyperosmolar stress conditions and, 2) demonstrate that protein misfolding and aberrant kinase activation contribute to ALS pathogenesis by FUS variants.
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Peresi, Eliana [UNESP]. "Polimorfismo gênico de receptores TLRs e citocinas: papel na resposta imune em pacientes com tuberculose pulmonar." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/101472.
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Universidade Estadual Paulista (UNESP)
It is estimated that one-third of the total world population is latently infected with M. tuberculosis and only 5-10% of the infected individuals will develop active TB disease during their life-time. The reason why some infected individuals develop active disease, while others do not is not yet entirely understood. Given the central role of TLR-2 in the incitement of inflammation, polymorphisms in its gene might be involved in both infectious and inflammatory diseases. The aim of this study was to evaluate the influence of TLR2 - 16934A/T and GT repeat polymorphisms on the immune response of PTB patients undergoing anti-TB treatment at different time points of anti-tuberculosis treatment: T1 (beginning), T2 (3 months) and T3 (end). For this we genotyped TLR2 -16934 and (GT)n repeats polymorphisms and evaluated the immune response of pulmonary tuberculosis patients during the time of anti-tuberculosis treatment. The present study suggests that TLR2 - 16934A/T and GT repeats polymorphisms can influence differential TLR-2, NF-κB and cytokine levels during anti-TB treatment. We also suggest that PTB patients with TLR2 - 16934 AA genotype may have a worst outcome of the disease, since they have a lower IFN-γ, cytokine essential to initiate the protective immunity to active TB. This association could not be made in our study due to the low number of patients evaluated. Since TLR-2 play a major role in initiating immune response against M. tuberculosis other polymorphisms in TLR2 would be crucial to better understand protective immune responses and may serve as biomarkers of protection or susceptibility to TB
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Peresi, Eliana. "Polimorfismo gênico de receptores TLRs e citocinas : papel na resposta imune em pacientes com tuberculose pulmonar /." Botucatu, 2012. http://hdl.handle.net/11449/101472.
Full textAbstract:
Orientador: Sueli Aparecida CalviCoorientador: Ana Carla Pereira
Coorientador: Edward A. Gravis
Banca: Lenice do Rosário Souza
Banca: Ida Maria Foschiani Dias Baptista
Banca: Fátima Regina Vilani Moreno
Banca: Ana Cláudia Pelizon
Resumo: Não disponível
Abstract: It is estimated that one-third of the total world population is latently infected with M. tuberculosis and only 5-10% of the infected individuals will develop active TB disease during their life-time. The reason why some infected individuals develop active disease, while others do not is not yet entirely understood. Given the central role of TLR-2 in the incitement of inflammation, polymorphisms in its gene might be involved in both infectious and inflammatory diseases. The aim of this study was to evaluate the influence of TLR2 - 16934A/T and GT repeat polymorphisms on the immune response of PTB patients undergoing anti-TB treatment at different time points of anti-tuberculosis treatment: T1 (beginning), T2 (3 months) and T3 (end). For this we genotyped TLR2 -16934 and (GT)n repeats polymorphisms and evaluated the immune response of pulmonary tuberculosis patients during the time of anti-tuberculosis treatment. The present study suggests that TLR2 - 16934A/T and GT repeats polymorphisms can influence differential TLR-2, NF-κB and cytokine levels during anti-TB treatment. We also suggest that PTB patients with TLR2 - 16934 AA genotype may have a worst outcome of the disease, since they have a lower IFN-γ, cytokine essential to initiate the protective immunity to active TB. This association could not be made in our study due to the low number of patients evaluated. Since TLR-2 play a major role in initiating immune response against M. tuberculosis other polymorphisms in TLR2 would be crucial to better understand protective immune responses and may serve as biomarkers of protection or susceptibility to TB
Doutor
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Wendlandt, Erik Bruce. "Macrophage microRNA and mRNA responses to stimulation of TLRs or upon infection with Leishmania infantum chagasi." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/1416.
Full textAbstract:
Leishmania are obligate intracellular protozoan parasites that are inoculated into human skin while a sand fly vector takes a blood meal with the resulting disease coined leishmaniasis. The twenty plus species of Leishmania known to cause human disease are found throughout tropical and subtropical regions of the world. Leishmaniasis affects at least eighty-eight countries with three hundred and fifty million people at risk for infection, resulting in an estimated seventy thousand deaths annually. Different species of Leishmania have developed distinct methods for host defense evasion, leading to a wide spectrum of pathologies within humans.
Prior studies of macrophage infections with Leishmania have shown global changes in macrophage mRNA expression. We hypothesized miRNAs are important modifiers of mRNA changes during Leishmania infection. Analysis of miRNA expression patterns revealed that changes were detected primarily during macrophage infection with the low virulent logarithmically growing promastigotes. Profiling studies of mRNA and miRNA changes upon infection with promastigotes in logarithmic growth revealed a decrease in miR-200b and increase in miR-744 levels whereas infections with the highly virulent metacyclic promastigotes revealed a decrease in miR-708 levels. Furthermore, microarray studies revealed differences in macrophage mRNA levels between macrophages infected with the low virulent promastigotes verses the highly virulent promastigotes. Correlative studies between miRNA and mRNA changes suggested some of Leishmania induced changes in mRNA levels may be modified by miRNAs.
The importance of Toll-like receptors (TLR) in detection of microbial products has been well-documented. Leishmania infection is known to initiate signaling through TLRs 2, 3, 4 and 9, of which TLRs 2, 4 and 9 signal through the adaptor molecule MyD88. We found that miR-200b, a microRNA decreased by infection of macrophages with the low virulent Leishmania promastigotes, regulates signaling through the TLR4 pathway by targeting and repressing MyD88 transcript levels. Furthermore, we have shown that MyD88 repression results in the decreased expression of the downstream effector molecules IL-6, CXCL9 and TNFΑ upon challenge with a TLR4 ligand. The suppression of miR-200b during Leishmania infection could serve to up-regulate inflammatory responses induced through TLR4 and other MyD88 dependent TLRs. This may be responsible, in part, for the decreased virulence of logarithmically growing compared to metacyclic promastigotes. Furthermore, low levels of inflammation may promote parasite survival by promoting the influx of inflammatory phagocytic cells to the site of infection in which the highly virulent parasites can survive.
Microarray studies revealed a remarkable increase in expression of metallothionein (MT) transcripts in macrophages infected with low virulent promastigotes but not in macrophages infected with the highly virulent promastigotes. To explore a possible mechanistic role for metallothioneins in leishmaniasis, we used knock-out mice for MT-1 genes. Bone-marrow derived macrophages from MT-1 knock-out mice (MT-KO) generated higher levels of reactive oxygen species upon incubation with Leishmania promastigotes. Consistently, the initial ROS-induced killing of promastigotes, which occurs during the first hours of infection, was greater twenty-four hours after infection of MT-1 KO bone-marrow macrophages than in our wild type controls. Overall, data presented in this thesis documents changes to macrophage mRNA and miRNA expression patterns upon infection with Leishmania promastigotes that correspond to the overall parasite survival in the host macrophage.
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Longo, Rosario Alessandro. "Dalla generazione di modelli 3D densi mediante TLS e fotogrammetria alla modellazione BIM." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13284/.
Full textAbstract:
La tesi tratta la ricerca di procedure che permettano di rilevare oggetti utilizzando il maggior numero di informazioni geometriche ottenibili da una nuvola di punti densa generata da un rilievo fotogrammetrico o da TLS realizzando un modello 3D importabile in ambiente FEM.
Il primo test si è eseguito su una piccola struttura, 1.2x0.5x0.2m, in modo da definire delle procedure di analisi ripetibili; la prima consente di passare dalla nuvola di punti “Cloud” all’oggetto solido “Solid” al modello agli elementi finiti “Fem” e per questo motivo è stata chiamata “metodo CSF”, mentre la seconda, che prevede di realizzare il modello della struttura con un software BIM è stata chiamata semplicemente “metodo BIM”. Una volta dimostrata la fattibilità della procedura la si è validata adottando come oggetto di studio un monumento storico di grandi dimensioni, l’Arco di Augusto di Rimini, confrontando i risultati ottenuti con quelli di altre tesi sulla medesima struttura, in particolare si è fatto riferimento a modelli FEM 2D e a modelli ottenuti da una nuvola di punti con i metodi CAD e con un software scientifico sviluppato al DICAM Cloud2FEM.
Sull’arco sono state eseguite due tipi di analisi, una lineare sotto peso proprio e una modale ottenendo risultati compatibili tra i vari metodi sia dal punto di vista degli spostamenti, 0.1-0.2mm, che delle frequenze naturali ma si osserva che le frequenze naturali del modello BIM sono più simili a quelle dei modelli generati da cloud rispetto al modello CAD. Il quarto modo di vibrare invece presenta differenze maggiori.
Il confronto con le frequenze naturali del modello FEM ha restituito differenze percentuali maggiori dovute alla natura 2D del modello e all’assenza della muratura limitrofa.
Si sono confrontate le tensioni normali dei modelli CSF e BIM con quelle ottenute dal modello FEM ottenendo differenze inferiori a 1.28 kg/cm2 per le tensioni normali verticali e sull’ordine 10-2 kg/cm2 per quelle orizzontali.
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Stevanović, Irena 1980. "Characterization of the in vivo functions of PrimPol, a novel TLS primase-polymerase." Doctoral thesis, Universitat Pompeu Fabra, 2013. http://hdl.handle.net/10803/293265.
Full textAbstract:
We have identified PrimPol, a yet uncharacterized protein that can act in vitro as a low
processivity polymerase able to bypasses thymine dimers in DNA. PrimPol localizes to both
the nucleus and mitochondria. In order to investigate functional role of this enzyme we have
generated genetrap mice and knock out mice where PrimPol expression is abolished. In cells
lacking PrimPol, we can see increased genomic instability even in the absence of damage,
indicating that it may suppress expression of common fragile sites. Upon UV damage and
aphidicolin treatment, there was a significant increase in chromosomal aberrations. In
genetrap embryos e14.5, PrimPol expression pattern was ectoderm and eye specific. This
was confirmed in the skin of adult where PrimPol was most highly expressed in the skin
compared to other tissues. PrimPol-/- UV damaged skin showed marked epidermal
hyperplasia compared to WT. We have also observed in aged PrimPol-/- mice, and in young
mice damaged by UV, upregulation of mitochondrial DNA copy number across different
tissues, implying that PrimPol may be dealing with the repair of oxidative damage as well. In
accordance with these findings, we hypothesize that PrimPol acts as a translesion polymerase
that can bypass bulky lesions generated by UV and reactive oxygen to promote the integrity
of nuclear and mitochondrial DNA and promote normal aging.Hemos identificado PrimPol, una proteína no caracterizada que actua in vitro como una polimerasa de bajo procesamiento que es capaz de evitar los dímeros de timina del ADN y que se localiza en el núcleo y en las mitocondrias. Para poder investigar la función de este enzima, hemos generado ratones genetrap y knock out en los cuales se ha abolido la expression de PrimPol. En las células que no expresan PrimPol podemos observar un aumento de la inestabilidad genómica incluso en ausencia de daño, indicando que podría suprimir la expression de sitios frágiles comunes. Tras inducir daño mediante radiación ultravioleta y tratamiento con afidicolina se observó un aumento significativo de aberraciones cromosómicas. En embriones y ratones adultos mediante tinción de LacZ y pudimos ver que PrimPol está altamente expresado en piel y en los ojos en comparación con otros tejidos. La piel dañada con UV en ratones PrimPol-/- mostró una marcada hiperplasia epidérmica en comparación con los ratones salvajes. También hemos observado que en ratones PrimPol-/- de edad avanzada y en ratones jóvenes con lesiones por UV hay un aumento del número de copias de ADN mitocondrial en diferentes tejidos, lo que sugiere que PrimPol podría estar también implicada en la reparación del daño oxidativo. De acuerdo con estos descubrimientos nos planteamos la hipótesis de que PrimPol pueda actuar como una translesion polimerasa que puede saltarse grandes lesiones inducidas por UV y especies reactivas de oxígeno y así promover la integridad del ADN nuclear y mitocondrial además de un normal envejecimiento.
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Rascão, Madalena da Silva Ruivo Coreixas. "Aquisição de dados LiDAR com TLS e HMLS para deteção de árvores individuais." Master's thesis, ISA, 2019. http://hdl.handle.net/10400.5/21291.
Full textAbstract:
Mestrado em Engenharia Florestal e dos Recursos Naturais / Instituto Superior de Agronomia. Universidade de LisboaLiDAR (Light Detection And Ranging) é um sistema baseado nos princípios de Deteção Remota que permite medir distâncias com base no tempo da trajetória da radiação laser, desde que é emitida pelo aparelho até que retorna ao recetor depois de ser refletida numa superfície sólida. A aplicabilidade deste sistema é abrangente a várias áreas da engenharia e prende-se com a capacidade que o mesmo tem de recolher e armazenar dados tridimensionais em forma de nuvens de pontos de qualquer objeto sólido sobre a superfície terrestre. No sector florestal, este sistema permite estimar características dos povoamentos e digitalizar uma extensa área de floresta, de uma forma automatizada, rápida e com detalhe na ordem dos milímetros. O objetivo do presente trabalho é avaliar a capacidade do sistema LiDAR na individualização da árvore comparando as coordenadas estimadas obtidas com dois métodos LiDAR - HMLS (Held-Hand Mobile Laser Scanner) e TLS (Terrestrial Taser Scanner) - com as coordenadas obtidas com GPS sub-métrico, pelo método tradicional de campo, num ensaio clonal de Eucalyptus globulus Labill. com 10 anos de idade. O presente estudo serviu também como primeira abordagem ao desempenho dos dois métodos LiDAR na obtenção de diâmetros às várias alturas do tronco, recorrendo aos algoritmos disponíveis no software R. Para a deteção das árvores individuais, os resultados demonstraram que, em média, o método TLS detetou 65,1% das árvores, enquanto o método HMLS detetou 44,7% das árvores, para todas as parcelas de estudo. Comprovou-se ainda que o levantamento com HMLS só é vantajoso para terrenos regulares e percursos retos. Concluiu-se que deve ser efetuada uma melhoria nos processos associados à utilização do algoritmo SLAM (Simultaneous Localization And Mapping) e salientou-se a importância de utilizar pontos de referência em campo para a obtenção de nuvens de pontos de melhor qualidade
N/A
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Sun, Yanshen. "Evaluating the quality of ground surfaces generated from Terrestrial Laser Scanning (TLS) data." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90577.
Full textAbstract:
Researchers and GIS analysts have used Aerial Laser Scanning (ALS) data to generate Digital Terrain Models (DTM) since the 1990s, and various algorithms developed for ground point extraction have been proposed based on the characteristics of ALS data. However, Terrestrial Laser Scanning (TLS) data, which might be a better indicator of ground morphological features under dense tree canopies and more accessible for small areas, have been long ignored. In this research, the aim was to evaluate if TLS data were as qualified as ALS to serve as a source of a DTM. To achieve this goal, there were three steps: acquiring and aligning ALS and TLS of the same region, applying ground filters on both of the data sets, and comparing the results.
Our research area was a 100m by 140m region of grass, weeds and small trees along Strouble's Creek on the Virginia Tech campus. Four popular ground filter tools (ArcGIS, LASTools, PDAL, MCC) were applied to both ALS and TLS data. The output ground point clouds were then compared with a DTM generated from ALS data of the same region. Among the four ground filter tools employed in this research, the distances from TLS ground points to the ALS ground surface were no more than 0.06m with standard deviations less than 0.3m. The results indicated that the differences between the ground extracted from TLS and that extracted from ALS were subtle. The conclusion is that Digital Terrain Models (DTM) generated from TLS data are valid.Master of Science
Elevation is one of the most basic data for researches such as flood prediction and land planning in the field of geography, agriculture, forestry, etc. The most common elevation data that could be downloaded from the internet were acquired from field measurements or satellites. However, the finest grained of that kind of data is 1/3m and errors can be introduced by ground objects such as trees and buildings. To acquire more accurate and pure-ground elevation data (also called Digital Terrain Models (DTM)), Researchers and GIS analysts introduced laser scanners for small area geographical research. For land surface data collection, researchers usually fly a drone with laser scanner (ALS) to derive the data underneath, which could be blocked by ground objects. An alternative way is to place the laser scanner on a tripod on the ground (TLS), which provides more data for ground morphological features under dense tree canopies and better precision. As ALS and TLS collect data from different perspectives, the coverage of a ground area can be different. As most of the ground extraction algorithm were designed for ALS data, their performance on TLS data hasn’t been fully tested yet. Our research area was a 100m by 140m region of grass, weeds and small trees along Strouble’s Creek on the Virginia Tech campus. Four popular ground filter tools (ArcGIS, LASTools, PDAL, MCC) were applied to both ALS and TLS data. The output ground point clouds were then compared with a ground surface generated from ALS data of the same region. Among the four ground filter tools employed in this research, the distances from TLS ground points to the ALS ground surface were no more than 0.06m with standard deviations less than 0.3m. The results indicated that the differences between the ground extracted from TLS and that extracted from ALS were subtle. The conclusion is that Digital Terrain Models (DTM) generated from TLS data are valid.
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NESREEN, HAMAD ABDELGAWWAD HAMAD. "Structural analysis of the interaction between FUS/TLS protein and non-coding RNA." Kyoto University, 2020. http://hdl.handle.net/2433/259065.
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ONeill, Mark Thomas. "The State of Man-in-the-Middle TLS Proxies: Prevalence and User Attitudes." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6180.
Full textAbstract:
We measure the prevalence and uses of Man-in-the-Middle TLS proxies using a Flash tool deployed with a Google AdWords campaign. We generate 15.2 million certificate tests across two large-scale measurement studies and find that 1 in 250 TLS connections are intercepted by proxies. The majority of these proxies appear to be benevolent, however we identify over 3,600 cases where eight malware products are using this technology nefariously. We also find thousands of instances of negligent, duplicitous, and suspicious behavior, some of which degrade security for users without their knowledge. Distinguishing these types of practices is challenging in practice, indicating a need for transparency and user awareness. We also report the results of a survey of 1,976 individuals regarding their opinions of TLS proxies. Responses indicate that participants hold nuanced opinions on security and privacy trade-offs, with most recognizing legitimate uses for the practice, but also concerned about threats from hackers or government surveillance. There is strong support for notification and consent when a system is intercepting their encrypted traffic, although this support varies depending on the situation. A significant concern about malicious uses of TLS inspection is identity theft, and many would react negatively and some would change their behavior if they discovered inspection occurring without their knowledge. We also find that a small but significant number of participants are jaded by the current state of affairs and have lost any expectation of privacy.
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Satterwhite, Christopher R. "Development of CPANEL, An Unstructured Panel Code, Using a Modified TLS Velocity Formulation." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1472.
Full textAbstract:
The use of panel codes in the aerospace industry dates back many decades. Recent advances in computer capability have allowed them to evolve, both in speed and complexity, to provide very quick solutions to complex flow fields. By only requiring surface discretization, panel codes offer a faster alternative to volume based methods, delivering a solution in minutes, as opposed to hours or days. Despite their utility, the availability of these codes is very limited due to either cost, or rights restrictions.
This work incorporates modern software development practices, such as unit level testing and version control, into the development of an unstructured panel code, CPanel, with an object-oriented approach in C++. CPanel utilizes constant source and doublet panels to define the geometry and a vortex sheet wake representation. An octree data structure is employed to enhance the speed of geometrical queries and lay a framework for the application of a fast tree method. The challenge of accurately calculating surface velocities on an unstructured discretization is addressed with a constrained Hermite Taylor least-squares velocity formulation. Future enhancement was anticipated throughout development, leaving a strong framework from which to perform research on methods to more accurately predict the physical flow field with a tool based in potential flow theory.
Program results are verified using the analytical solution for flow around an ellipsoid, vortex lattice method solutions for simple planforms, as well an anchored panel code, CBAERO. CPanel solutions show strong agreement with these methods and programs. Additionally, aerodynamic coefficients calculated via surface integration are consistent with those calculated from a Trefftz plane analysis in CPanel. This consistency is not demonstrated in solutions from CBAERO, suggesting the CHTLS velocity formulation is more accurate than more commonly used vortex core methods.
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Muniz, Rafael Oliveira Rondon. "Desenvolvimento de um simulador antropomórfico para simulação e medidas de dose e fluxo de nêutrons na instalação para estudos em BNCT." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-15082011-082735/.
Full textAbstract:
A instalação do IPEN para pesquisas em BNCT (Terapia por Captura de Nêutrons em Boro) utiliza o canal de irradiação número 3 do reator IEA-R1, no qual tem-se um campo misto de radiação nêutrons e gama. As pesquisas em andamento necessitam que o campo de radiação, na posição de irradiação de amostra, tenha na composição os nêutrons térmicos maximizados e os componentes de nêutrons epitérmicos, rápidos e radiação gama minimizados. Este trabalho foi desenvolvido com o objetivo de avaliar se o campo de radiação atual na instalação é adequado aos trabalhos em BNCT. Para cumprir com este objetivo, uma metodologia para dosimetria de nêutrons térmicos e radiação gama em campos mistos de altas doses, que não era disponível no IPEN, foi implantada no Centro de Engenharia Nuclear do IPEN, utilizando dosímetros termoluminescentes TLDs 400, 600 e 700. Para as medidas de fluxo de nêutrons térmicos e epitérmicos foram utilizados detetores de ativação de ouro aplicando a técnica de razão de cádmio. Um simulador antropomórfico cilíndrico composto de discos de acrílico foi desenvolvido e testado na instalação e para obter valores teóricos do fluxo de nêutrons e a dose ao longo do simulador antropomórfico foi utilizado o código computacional DOT 3.5. Na posição correspondente a aproximadamente metade do comprimento do cilindro do simulador antropomórfico, foram obtidos os seguintes valores: fluxo de nêutrons térmicos (2,52 ± 0,06).108n/cm2s, epitérmicos (6,17 ± 0,26).107n/cm2s, dose absorvida devido a nêutrons térmicos de (4,2 ± 1,8)Gy e devido a radiação gama (10,1 ± 1,3)Gy. Os valores obtidos mostram que os fluxos de nêutrons térmicos e epitérmicos são adequados para os estudos em BNCT, porém, a dose devido a radiação gama está elevada, indicando que a instalação deve ser aprimorada.IPEN facility for researches in BNCT (Boron Neutron Capture Therapy) uses IEA-R1 reactor\'s irradiation channel number 3, where there is a mixed radiation field neutrons and gamma. The researches in progress require the radiation fields, in the position of the irradiation of sample, to have in its composition maximized thermal neutrons component and minimized, fast and epithermal neutron flux and gamma radiation. This work was developed with the objective of evaluating whether the present radiation field in the facility is suitable for BNCT researches. In order to achieve this objective, a methodology for the dosimetry of thermal neutrons and gamma radiation in mixed fields of high doses, which was not available in IPEN, was implemented in the Center of Nuclear Engineering of IPEN, by using thermoluminescent dosimeters TLDs 400, 600 and 700. For the measurements of thermal and epithermal neutron flux, activation detectors of gold were used applying the cadmium ratio technique. A cylindrical phantom composed by acrylic discs was developed and tested in the facility and the DOT 3.5. computational code was used in order to obtain theoretical values of neutron flux and the dose along phantom. In the position corresponding to about half the length of the cylinder of the phantom, the following values were obtained: thermal neutron flux (2,52 ± 0,06).108n/cm2s, epithermal neutron flux (6,17 ± 0,26).107.106n/cm2s, absorbed dose due to thermal neutrons (4,2 ± 1,8)Gy and (10,1 ± 1,3)Gy due to gamma radiation. The obtained values show that the fluxes of thermal and epithermal neutrons flux are appropriate for studies in BNCT, however, the dose due to gamma radiation is high, indicating that the facility should be improved.
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Perego, Jessica. "Modulation pharmacologique des voies de signalisation des TLRs par le Guanabenz, un inhibiteur de la réponse au stress." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4066.
Full textAbstract:
On a récemment mis en évidence l'existence d'une étroite interconnexion entre la perception d'éléments d'origine microbienne (qui se fait à travers les récepteurs de l’immunité innée tels que les TLRs) et l'homéostasie du réticulum endoplasmique. En situation de stress, une grande quantité de protéines mal repliées s'accumule dans le réticulum, déclenchant une série de réponses cellulaires connues sous le nom de "Unfolded Protein Response" (UPR). On a découvert que l'activation de l'UPR contribue à la réponse inflammatoire, en particulier chez les cellules dendritiques. GADD34/PP1 est un complexe protéique qui dé-phosphoryle eIF2α et participe à la restauration de la synthèse protéique. On a démontré que GADD34 a aussi un rôle dans le contrôle de l’expression des cytokines pro-inflammatoires, en particulier l'interféron de type I. Le but de cette thèse est de clarifier comment la voie de signalisation des TLRs et le UPR s'intercroisent et comment est-ce qu'on peut exploiter cette interaction dans des cas pathologiques J’ai pu démontrer, à l'aide de cellules dendritiques d’origine humaine et murine, que le guanabenz (GBZ), un inhibiteur du complexe GADD34/PP1, est capable de bloquer l'activation des récepteurs TLRs endosomaux. Cet inhibiteur est également capable de bloquer le choc septique dépendent de TLR9 et de baisser le niveau d’autoanticorps dans un modèle lupique. En conclusion, j'ai pu démontrer, aussi bien in vitro que in vivo, que le guanabenz est capable d'inhiber les TLRs endosomaux à travers un nouveau mécanisme d’inhibition sur CH25H, une enzyme du métabolisme du cholestérol, qui a été récemment découvert comme faisant partie de l'immunité innéeSustained immune reaction is strictly interconnected to pathogenic situations. For this reason, the activation of immune cells is controlled by multiple pathways. A cross-talk between microbial sensing and Endoplasmic Reticulum (ER) homeostasis has been discovered. Abnormal accumulation of proteins in the ER is a sign of cellular malfunction and triggers emergency rescue pathways, collectively known as the Unfolded Protein Response (UPR). UPR induction triggers or amplifies inflammatory signals by dendritic cells (DCs). GADD34/PP1 is a holophosphatase complex that dephosphorylates eIF2α and participates in the UPR feedback loop, by restoring protein translation. It has been shown that GADD34 plays an important role in controlling the expression of pro-inflammatory cytokines, especially type I interferon. In dendritic cells (DCs), pathogens are sensed by Pathogen Recognition Receptors (PRRs); the better characterised class of PRRs being the Toll-Like Receptors (TLRs). Thus, the aim of my thesis is to investigate how TLRs and ER-signalling pathways intersect and how this can be used to control pathogenic states, with particular attention for the GADD34/PP1 complex. Using both human and mouse DCs, we show that guanabenz (GBZ), an inhibitor of the GADD34/PP1 complex, blocks endosomal TLRs activation. The same inhibitor rescues mice viability in a TLR-dependent septic shock model and controls the circulating autoantibodies in a lupus model. Our studies show that TLR9 is particularly sensitive to GBZ. We show also that GBZ has a previously unidentified effect on CH25H, an enzyme that hydroxylates the cholesterol in 25-hydroxycholesterol, recently linked to TLRs signaling
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Frenzel, Laurent. "Régulations épigénétiques et rôles de la protéine Btk dans l'expression du TNF-α par la voie des TLRs." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01071591.
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La Bruton tyrosine kinase ou Btk est une protéine dont le rôle dans la maturation des lymphocytes B est connu depuis plusieurs années. Par contre, son rôle dans le contrôle de l'immunité innée est moins établi. Nous avons montré que, en réponse à la voie des Toll like Receptors ou TLRs, Btk régule la stabilité de l'ARN messager du TNF-α par l'intermédiairede la protéine TTP ou Tristétraproline. Par ailleurs, nous avons montré que l'expression d'un microARN, le miR-346, régulait négativement la protéine Btk et donc la synthèse de TNF-α. L'amplification de l'expression de ce miR-346 par transfection permet d'avoir un effet anti-TNF-α et anti-Btk interessant notamment dans le modèle cellulaire de la polyarthrite rhumatoïde. Enfin, nous avons montré que, en réponse au TLRs, la modulation de l'expression du TNF-α en fonction de l'état de méthylation de l'ADN et d'acétylation des histones dépendait directement de l'expression du couple miR-346 et Btk. Btk est donc une protéine charnière dans le contrôle de l'inflammation par les mécanismes épigénétiques que sont les miARNs, la méthylation de l'ADN et l'acétylation des histones. Sur le plan thérapeutique, l'inhibition de cette protéine par ces différents mécanismes de régulation semble donc être très interessante, à la fois dans les maladies inflammatoires et néoplasiques.
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Mobit, Paul Njom. "Monte Carlo and experimental studies of dose measurement in radiotherapy with LiF-TLDs and other solid state dosemeters." Thesis, Institute of Cancer Research (University Of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244763.
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Moretti, Isabele Fattori. "Receptor do tipo Toll 4 dentre os TLRs de membrana plasmática possui um papel na malignidade de astrocitomas." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5138/tde-05122018-131346/.
Full textAbstract:
Os receptores do tipo Toll (TLRs) são as primeiras proteínas do sistema imune a identificarem distúrbios, reconhecem patógenos como bactérias, fungos e vírus. Como o processo inflamatório possui um importante papel em diversas doenças, os TLRs foram considerados potenciais alvos em estratégias terapêuticas, incluindo o tratamento de câncer. No entanto, o papel dos TLRs permanece ambíguo. Esse estudo teve como objetivos analisar os níveis de expressão dos TLRs presentes em membrana plasmática, TLRs (TLR1, TLR2, TLR4, TLR5, TLR6) em astrocitomas de diferentes graus de malignidade (grau II-IV), tumor mais prevalente do Sistema Nervoso Central (SNC). Nós demonstramos que a expressão dos TLRs foi mais alta em amostras de astrocitomas comparadas com tecido cerebral não-neoplásico, por qRT-PCR. A expressão gênica e proteica foi observada em células de linhagem de glioblastoma (GBM) U87MG e A172, mostrando sua presença em células tumorais. Foi observada expressão associada entre os heterodímeros TLR1- TLR2. Em GBMs, o subtipo mesenquimal mostrou maior nível de expressão dos TLRs comparados aos subtipos clássico e proneural. Com o objetivo de identificar o papel dos TLRs nas células tumorais, foi selecionado dentre os TLRs o que apresentou maior nível de expressão, o TLR4, e realizamos ensaios funcionais estimulando a U87MG com LPS, um agonista natural para TLR4. A taxa de proliferação da célula tratada com LPS foi similar a não tratada. No entanto, foi observado a ativação do NF-kB após 12hrs do estímulo com LPS. Quando a sinalização do receptor foi inibida por um composto químico (VGX-1027), o nível de proliferação da U87MG decaiu. Adicionalmente, análise in silico revelou uma forte associação dos TLRs hiperexpressos com aumento da expressão de genes relacionados à sinalização do ciclo celular, inflamassoma e ripoptossoma. O que sugere serem os TLRs alvos para complementação do tratamento do câncerToll-like receptors (TLRs) are the first to identify disturbances in the immune system, recognizing pathogens such as bacteria, fungi, and viruses. Since the inflammation process plays an important role in several diseases, TLRs have been considered potential therapeutic targets, including treatment for cancer. However, TLRs\' role in cancer remains ambiguous. This study aims to analyze the expression levels of plasmatic cell membrane TLRs (TLR1, TLR2, TLR4, TLR5, and TLR6) in different grades (II-IV) of human astrocytoma, the most prevalent tumor of CNS. We demonstrated that TLR expressions were higher in astrocytoma samples compared to non-neoplastic brain tissue, by qRT-PCR. The genes and proteins expressions were observed in U87MG and A172 GBM cell lines, proving their presence in the tumor cells. Associated expressions between the known heterodimers TLR1-TLR2 were found in diffusely infiltrative astrocytoma. In GBM, the mesenchymal subtype showed higher levels of TLR expressions in relation to classical and proneural subtypes. Aiming to indentify the role of TLRs in tumor cells, we chose the highest TLR expressed in GBM cells, the TLR4, and performed functional assays stimulating U87MG-GBM cell line with LPS, a natural agonist for TLR4. The proliferation rate was similar in treated and non-treated cell with LPS. However, NF-kB activation was detected after 12hrs of LPS stimulation. When TLR4 signaling pathway was inhibited by a chemical compound (VGX-1027) a decrease in the proliferation rate was observed. Additionally, in silico analysis revealed a strong association of TLRs upregulation with increased expression level of genes related to cell cycle, inflammasome and ripoptosome pathways, further highlighting TLRs as interesting targets for cancer complementary treatment