Made available in DSpace on 2015-04-20T12:33:26Z (GMT). No. of bitstreams: 1 Leandro.pdf: 2831865 bytes, checksum: 5804d85c95f338cf4054c799f4dfd45d (MD5) Previous issue date: 2011-10-07 / Voice calls based on Voice over Internet Protocol (VoIP) technology are liable to several impairments from both application and network layer, such as codec compression, end-to-end delay, and packet loss. For years, this problem has been challenging researchers and practitioners, who have been designing and improving QoS control mechanisms for VoIP applications. Such mechanisms aim to make optimum use of network and terminal resources so as to minimize the effects of network impairments on voice quality. Among the several proposed QoS control mechanisms for VoIP, some of them seek to adapt the voice flow or other VoIP-related parameters in accordance with significant changes in the network, end users preferences, or service providers requirements. VoIP systems are particularly likely to require a dynamic adaptation solution for dealing with the complex trade-off between speech quality and impairments, because of the decentralized control nature of IP networks and the stochastic nature of data packet delivery. Although the existing adaptive solutions for QoS control of VoIP show some performance improvement and exhibit some sort of feedback, they do not provide explicit focus on the control loop. This document shows the current progress of our thesis, which addresses the adjustment of internal parameters of VoIP terminals (at application layer) that affect the voice flow, with the aim of improving speech quality in response to changes in network conditions. It is not in the scope of the thesis to propose adaptive solutions that focus exclusively on signaling, billing, security issues, or operate at the network layer. Therefore, this thesis addresses the problem of how adjust encoding parameters in response to variations in delay and packet loss, in order to optimize speech quality. The objective is to optimize user-perceptible attributes of speech, under the perspective of self-adaptive software systems. The emphasis is not to develop new audio codecs, but to build a control loop in the core of sender and receiver terminals to adapt voice flow settings according to network conditions. The main contributions of this thesis are the following: determination of user s perception during codec switching; parametrization of codec precedence for supporting codec switching decision; explicit design of a monitoring analysis planning execution control loop as the core of the adaptation process; and efficiency analysis of feedback message exchanging. / Chamadas de voz baseadas na tecnologia VoIP (Voice over Internet Protocol) estão suscetíveis a degradações diversas, provenientes tanto da camada de aplicação, como da camada de rede, tais como compressão do codec, atraso fim a fim e perda de pacotes. Durante anos, esse problema tem desafiado pesquisadores e profissionais, que têm concebido e melhorado mecanismos de controle de QoS para aplicações VoIP. Tais mecanismos visam otimizar a utilização dos recursos da rede e do terminal VoIP de modo a minimizar os efeitos deletérios da rede subjacente sobre a qualidade de voz. Entre as várias propostas de mecanismos de controle de QoS para VoIP, alguns deles procuram adaptar o fluxo de voz ou outros parâmetros VoIP de acordo com mudanças significativas na rede, preferências de usuário, ou requisitos dos provedores de serviços VoIP. Sistemas VoIP particularmente exigem soluções de adaptação dinâmica para lidar com a complexa relação de compromisso entre qualidade de voz e fatores de degradação, por causa da natureza descentralizada e estocástica das redes IP na entrega de pacotes de voz. Embora as soluções adaptativas existentes para controle de QoS em VoIP mostrem alguma melhora de desempenho e apresentem algum tipo de feedback, elas não fornecem foco explícito na ciclo de controle (control loop). Este documento mostra o progresso atual da nossa tese, que aborda o ajuste de parâmetros internos de terminais VoIP (camada de aplicação) que afetam o fluxo de voz, com o objetivo de melhorar a qualidade da fala em resposta a mudanças nas condições da rede. Não faz parte do escopo da tese abordar soluções adaptativas que se concentram exclusivamente em sinalização, bilhetagem, problemas de segurança, ou que operam no nível da camada de rede. Portanto, esta tese aborda o problema da concepção e avaliação de estratégias adaptativas que explorem as relações de compromisso entre qualidade da fala e os seguintes fatores de degradação: compressão do codec, atraso fim a fim e perda de pacotes. A finalidade é otimizar atributos da fala perceptíveis aos usuário, sob a perspectiva de sistemas de software autoadaptativo. A ênfase não reside em desenvolver novos codecs de áudio, mas sim em desenvolver um ciclo de controle como entidade central de um terminal VoIP, que possa adaptar as configurações do fluxo de voz de acordo com as condições da rede. As principais contribuições desta tese são as seguintes: determinação da percepção do usuário durante a comutação de codec; parametrização de precedência de codecs para suporte de decisão de comutação de codec; enfoque no ciclo de controle baseado nas atividades de monitoramento análise planejamento execução como núcleo do processo de adaptação; e análise de eficiência de troca de mensagens de feedback.

Le cancer papillaire de la thyroïde (CPT) est la tumeur endocrine la plus fréquente. Des anomalies moléculaires activant la voie des MAPK (Mitogen-Activated Protein Kinases) sont identifiées, de façon mutuellement exclusive, dans environ 70% des cas. Il s’agit de réarrangements chromosomiques, le plus souvent de type RET/PTC (10%), de mutations ponctuelles activatrices des trois isoformes de l’oncogène RAS (H, N et K-RAS) (10%), ou de l’oncogène B-RAF (50%). La mutation « hot spot » B-RAFV600E est la plus fréquemment identifiée, elle est associée à une plus grande agressivité clinique (diagnostic à un stade tardif, risque de récidives et de décès accru). Ces évènements moléculaires ont pour conséquence commune l’activation de la voie des MAPK, se traduisant en aval par la phosphorylation de MEK (Mitogen-activated Extracellular signal-Regulated Kinase) puis de ERK (Extracellular signal-Regulated Kinase). Cette dernière est régulée négativement par des phosphatases, appartenant à la famille des Dual Specificity Phosphatases (DUSPs), d’expression ubiquitaire, et en particulier de deux phosphatases spécifiques de ERK, l’une cytoplasmique (DUSP6) et l’autre nucléaire (DUSP5). Nous avons fait l’hypothèse que ces phosphatases pouvaient être soit des gènes suppresseurs de tumeurs (leur perte d’expression conduisant à une augmentation de phosphorylation de ERK et une prolifération accrue), soit des marqueurs du degré d’activation de la voie MAPK dans le cadre d’une boucle de rétrocontrôle négatif. Ceci nous a conduits à analyser la régulation et l’expression de ces phosphatases dans trois modèles : la lignée cellulaire PCCL3 (thyroïde de rat), exprimant l’un des trois principaux oncogènes mutés dans les CPT (RET/PTC3 ou H-RASV12 ou B-RAFV600E) sous le contrôle d’un promoteur inductible par la doxycycline, des lignées cellulaires humaines dérivant de CPT et des CPT humains. (...) / Papillary thyroid cancer (PTC) is the most common endocrine malignancy. Mutually exclusive and activating alterations of the MAPK pathway (Mitogen-Activated Protein Kinases) are identified in 70% of cases. Common mutations found in PTCs are point mutation of the B-RAF (50%) and RAS genes (10%) as well as RET/PTC chromosomal rearrangements (10%). The hot spot B-RAFV600E mutation is the most frequently alteration identified and is connected with agressive clinical characteristics (high stage at diagnosis, high recurrence risk and death). These molecular events lead to constitutive activation of the MAPK pathway, resulting in MEK (Mitogen-activated Extracellular signal-Regulated Kinase) and ERK (Extracellular signal-Regulated Kinase) phosphorylation. ERK is negatively regulated by phosphatases and among them, Dual Specificity Phosphatases (DUSPs), ubiquitary expressed, in particular two ERK-specific phosphatases DUSP5 (nuclear) and DUSP6 (cytosolic). We hypothesized that these phosphatases could have tumor supressor properties (i.e. their loss would be associated with an increase in MAPK pathway activation) or may serve as a surrogate marker of MAPK pathway activation in the context of a negative feedback loop. We analysed regulation and expression of both phosphatases in 3 models: three PCCL3 cell lines (rat thyroid cells) expressing one of the most common oncogene identified in PTCs (RET/PTC3 or H-RASV12 or B-RAFV600E) under the control of a doxycycline-inducible promoter, human PTC-derived cell lines and human PTC. We demonstrated that MAPK pathway activation was correlated with induction of DUSP5 and DUSP6. These phosphatases are involved in a negative feedback loop that contributes to a tight regulation of phospho-ERK levels. DUSP5 and DUSP6 mRNA are overexpressed in human PTCs, especially in B-RAF mutated tumors suggesting a higher MAPK signaling output in these agressive PTCs. Silencing of DUSP5 and/or DUSP6 by small interfering RNA does not affect proliferation of human B-RAFV600E thyroid carcinoma-derived cell lines, suggesting the lack of tumor suppressor gene role. Compensatory changes in expression of DUSPs when a specific one is inactivated may explain this lack of effect. On the opposite, a DUSP6 pharmacological inhibitor induced a concentration dependent decrease in proliferation of human B-RAFV600E cells, suggesting « off-target » effect of this inhibitor. In a second part, we analysed the regulation of DUSP5 expression, which is a target of the MAPK pathway activation. We demonstrated, using pharmacological inhibitors, that DUSP5 is an early response gene, regulated mostly by the MAPK pathway, at the transcriptional level. Two contiguous CArG boxes that bind serum response factor (SRF) were found in a 1Kb promoter region, as well as several E twenty-six transcription factor family binding sites (EBS). These sites potentially bind Elk-1, a transcription factor activated by ERK1/2. Using wild type or mutated DUSP5 promoter reporters, we demonstrated that SRF plays a crucial role in serum induction of DUSP5 promoter activity, the proximal CArG box being important for SRF binding in vitro and in living cells. Moreover Elk-1 was bound in vitro to a promoter region containing the proximal CArG box and a putative EBS. Its specific binding to SRF was necessary to elicit promoter response to dominant positive Elk-VP16 and to enhance the response to serum stimulation. Altogether our results suggest that the MAPK pathway is more active in B-RAFV600E PTC than in PTC with other genetic alteration and could explain their clinical agressivity. DUSP5 and DUSP6, as well as phosphorylated MEK, are markers of activation of the MAPK pathway. Neither phosphatase has tumor suppressor properties in our thyroid cancer cell models. Our results suggest redundancy and functional compensation among DUSPs. (...)

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Spoken communication between humans generate information in two channels; the primary channel, linked to the syntactic-semantic part of the speech (what a person is litteraly saying); the secondary channel conveys paralinguistic information (tone, emotional state and gestures). This study examines the paralinguistic part of the speech, more specific the tone and emotional state. The study examines if there is a correlation between human speech and the opinion of a participant to a language café based conversation. The language café conversations is moderated by the social robot platform Furhat created by Furhat Robotics. The report is written from two perspectives. A data scientific view where identified emotions in audio files are analysed with machine learning algorithms and mathematical models. Vokaturi, an emotion recognition software, analyses the audio files and quantifies the emotional attributes. The classification model is based upon these attributes and the answers from the language café survey. Speech emotion recognition is also evaluated as a method for gathering customer opinions in a customer feedback loop. The results show an accuracy of 61% and indicates that some sort of prediction is possible. However there is no clear correlation between the recorded human voice and the participants opinion of the conversation. In the discussion part the difficulties of creating a high accuracy model with current data is analysed. It also contains a hypothetic analysis of the model as a gathering method for customer data. / En person som talar sprider information genom en primär samt en sekundär kanal. Den primära kanalen är kopplat till den syntaktiska semantiken av talet (vad personen bokstavligen säger), medan den sekundära kanalen är kopplat till den paralingvistiska delen (ton, känslotillstånd och gester). Denna studie undersöker den paralingvistiska delen av talet, mer specifikt en människas tonläge och känsla. Studien undersöker om det finns någon korrelation mellan mänskligt tal och vad personen tycker om ett parkcafé-samtal. Parkcafé samtalen i denna studie har genomförts tillsammans med den sociala roboten Furhat skapad av Furhat Robotics. Rapporten är skriven ur två perspektiv. Ett datatekniskt perspektiv där känsloyttringar i ljudfiler analyseras med hjälp av maskininlärning och matematiska modeller. Med hjälp av Vokaturi, som tillhandahåller mjukvara för känsloigenkänning av ljud, analyseras inspelade konversationer och attribut för olika känslor kvantifieras. Klassificeringsmodellen skapas sedan av dessa attribut, svar på enkätundersökningar (del ett) samt av författarna egen-annoterade ljudfiler (del två). Dessutom analyseras känsloigenkänning som metod för insamling av användaråsikter ur ett företagsekonomiskt perspektiv. Resultaten påvisar en träffsäkerhet på ca 62% och 61% för del ett respektive två och pekar på att någon form av prediktion är möjlig. Ett tydligt samband mellan deltagarens röst och dess åsikt om samtalet är dock svårt att finna med dessa resultat. I analysen och slutsatsen diskuteras svårigheterna med att ta fram en funktionell modell med tillgänglig data samt en hypotetisk diskussion kring modellen som del av en customer feedback loop.

Cotutelle - Mélanie Dieudé / L’ischémie-reperfusion inhérente à toute transplantation d’organe solide induit l’apoptose des cellules endothéliales. Les cellules endothéliales apoptotiques sécrètent des vésicules extracellulaires apoptotiques de type exosome (ApoExo). L’internalisation des ApoExo par les cellules endothéliales (CE) adjacentes conduit à des changements fonctionnels importants dont le dysfonctionnement endothélial. Cependant, les mécanismes d’internalisation des ApoExo par les CE sont méconnus. Des marqueurs fluorescents spécifiques aux protéines et à l’ARN ont été utilisés afin de marquer spécifiquement les ApoExo et étudier leur internalisation par microscopie confocale et cytométrie de flux. Les ApoExo ont été internalisés par les CE en fonction du temps et de la concentration. L’inhibition des voies classiques d’endocytose à l’aide d’inhibiteurs pharmacologiques et d’interférence par ARN n’a pas réduit les niveaux d’internalisation des ApoExo. Le blocage de la phosphatidylsérine des ApoExo avec l’annexine-V a réduit leur internalisation. L’analyse ultrastructurelle par microscopie électronique des CE a révélé la présence de structures lamellipodes importantes pour la macropinocytose dont l’inhibition a diminué le transfert d’ARN et de protéines dans les CE. L’analyse par RT-qPCR a révélé que l’ARNm PCSK5, le plus enrichi dans les ApoExo, est augmenté dans les CE traitées aux ApoExo. Cette augmentation est abolie avec ApoExo exempts d’ARNm PCSK5. Ces résultats démontrent que les ApoExo sont activement internalisés par macropinocytose dépendante de la phosphatidylsérine, favorisant leur internalisation en augmentant l’activité macropinocytique des CE. Les ApoExo transfèrent ainsi des ARN fonctionnels capables de moduler le protéome des CE. Ces résultats ouvrent de nouvelles portes pour la prévention de l’internalisation des ApoExo, et donc de la dysfonction endothéliale. / Ischemia-reperfusion injury inherent to solid organ transplantation induces endothelial apoptosis, releasing apoptotic exosome-like vesicles (ApoExo) which in turn induce endothelial dysfunction. We showed that ApoExo modulates gene expression, functions, and morphology of endothelial cells (EC) towards endothelial dysfunction. However, the mechanism by which EC internalize ApoExo remains unclear. Fluorescent probes specifically targeting proteins and RNA were used to track ApoExo uptake in EC by flow cytometry and confocal microscopy. Pharmacological inhibitors and gene silencing were used to probe uptake mechanisms. RNA and protein expression were quantified using Taqman RT-qPCR and immunoblot, respectively. Uptake of ApoExo by EC was observed in a time- and concentration-dependent manner. Inhibition of clathrin- and caveolae-dependent endocytosis did not decrease ApoExo internalization by EC. Blocking phosphatidylserine on ApoExo surface with annexin-V decreased ApoExo uptake. Ultrastructural analysis of serum-starved EC via electron microscopy revealed lamellipodia-like structures, hallmark of macropinocytosis, whose number increased following ApoExo exposure. Inhibition of macropinocytosis abrogated both RNA and protein transfers from ApoExo to EC. The most enriched mRNA in ApoExo, coding for PCSK5, showed enhanced levels in ApoExo-treated EC along with increased PCSK5 protein levels. This was abrogated by both macropinocytosis inhibition and depletion of PCSK5 mRNA in ApoExo. These results demonstrate that EC actively internalize ApoExo through phosphatidylserine-dependent macropinocytosis, and moreover, that ApoExo further increase macropinocytosis. These findings also show that functional RNAs can be delivered to EC through ApoExo. These results open new avenues for preventing ApoExo internalization and counteracting the development of endothelial dysfunction.

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The professional development of a career counselling intern on a satellite campus at a distance education institution was facilitated with the use of a heutagogic learning strategy. The heutagogic learning process was recorded by reflective writing based on Kolb's experiential learning model. This research is a disquisition of the reflective dataset. The research is an autoethnographic case study in the constructionist paradigm with a creative analysis process. During the research process features about the benefits of heutagogic learning in the professional development of the career counselling intern were critically constructed. The findings of the research are captured in memescapes showing mindset changes and mental transformations on patterns which describe the theory-praxis gap, diversity, wellness, the macro-ethic. The recommendations include the hope that these findings will feed through to inform future career counselling internships in the IOP field. / Industrial & Organisational Psychology / MCom (Industrial and Organisational Psychology)

The professional development of a career counselling intern on a satellite campus at a distance education institution was facilitated with the use of a heutagogic learning strategy. The heutagogic learning process was recorded by reflective writing based on Kolb's experiential learning model. This research is a disquisition of the reflective dataset. The research is an autoethnographic case study in the constructionist paradigm with a creative analysis process. During the research process features about the benefits of heutagogic learning in the professional development of the career counselling intern were critically constructed. The findings of the research are captured in memescapes showing mindset changes and mental transformations on patterns which describe the theory-praxis gap, diversity, wellness, the macro-ethic. The recommendations include the hope that these findings will feed through to inform future career counselling internships in the IOP field. / Industrial and Organisational Psychology / M. Com. (Industrial and Organisational Psychology)

Recent episodes of financial instability have motivated researchers as well as policy makers to intensify research on financial stability. This thesis contributes to current research and policy discussion by elaborating and empirically testing methodologies, which can be used to measure financial sector vulnerabilities and identify potential risks for financial stability. It further focuses on the link between real and the financial sector as well as possible implications of household financial distress on the aggregate economy. Together with the proposed framework we provide the survey of the current literature on these topics as well as the empirical results. We argue in favour of stress testing methodologies covering the key risks on banks' balance sheets. These frameworks can also be used for emerging markets where data availability is typically limited. It is shown that due to high volatility of credit growth in emerging economies, the static approach assuming constant balance sheet items is not very appropriate. Furthermore, the feedback effect between the financial sector and the real economy might play an important role under certain assumptions, and therefore it should be taken into account by policy makers. This effect can also emerge in the real sector itself as potential instability can...

This thesis is concerned with the phenomenon of passivity in literature, particularly with how it manifests itself through actions, stagnation and means of existence of chosen literary characters and subjects. It concentrates on such figures that are inactive or apathetic, whose actions lack the clearly articulated meaning and purpose and it often seems that they vegetate rather than live an active life. The main theme is the relationship between passivity and activity and turning the passivity into a creative principle. The thesis applies the performative theory on the literary text and sees passivity of the literary characters or subjects as a means of their art performance which offers new interpretations of examining texts and the passivity in general. Methodologically the thesis is based especially on the performative theory of Erika Fischer-Lichte, but also on the anthropological research of transition rituals, theoretical concepts of mediality, John Austin's speech-act theory or on selected philosophical thesis of Maurice Merleau-Ponty and post-structuralist philosophy of Gilles Deleuze and Jacques Derrida. As primary texts for the analysis serve the short story The Overcoat (Шинель, 1842) by Nikolai Vasilievich Gogol, the novella Bartleby, the Scrivener (1853) by Herman Melville, The Book...