This work explores two methods for practical cryptography on mobile devices. The first method is a quantum-resistant key-exchange protocol proposed by Jao et al.. As the use of mobile devices increases, the deployment of practical cryptographic protocols designed for use on these devices is of increasing importance. Furthermore, we are faced with the possible development of a large-scale quantum computer in the near future and must take steps to prepare for this possibility. We describe the key-exchange protocol of Jao et al. and discuss their original implementation. We then describe our modifications to their scheme that make it suitable for use in mobile devices. Our code is between 18-26% faster (depending on the security level). The second is an highly optimized implementation of Miller's algorithm that efficiently computes the Optimal Ate pairing over Barreto-Naehrig curves proposed by Grewal et al.. We give an introduction to cryptographic pairings and describe the Tate pairing and its variants. We then proceed to describe Grewal et al.'s implementation of Miller's algorithm, along with their optimizations. We describe our use of hand-optimized assembly code to increase the performance of their implementation. For the Optimal Ate pairing over the BN-446 curve, our code is between 7-8% faster depending on whether the pairing uses affine or projective coordinates.

Pseudomonas aeruginosa est un pathogène opportuniste impliqué dans les infections nosocomiales. Sa multi résistance aux antibiotiques s’exerce notamment grâce à l’activation de pompes d’efflux membranaires. Il s’agit de systèmes tripartites composés d’une porine de la famille OMF (Outer Membrane Factor) ancrée dans la membrane externe, d’un transporteur de la famille des RND (Resistance Nodulation Division) localisé dans la membrane interne et d’un adaptateur périplasmique de la famille des MFP (Membrane Fusion Protein) qui consolide l’ensemble. Le travail réalisé au cours de cette thèse apporte une contribution à la compréhension des mécanismes d’assemblage et d’ouverture des pompes d’efflux ainsi qu’à leur régulation grâce au développement de nouveaux outils empruntés à la physique, à la biochimie et à la microbiologie. Une première étude a permis de déterminer la stoechiométrie d’interaction entre MexA et OprM par gel bleu natif (Ferrandez, Monlezun et al. 2012). Une deuxième étude a été consacrée, dans le cadre d’une collaboration avec l’équipe de B. Le Pioufle (ENS Cachan), à la caractérisation par électrophysiologie de l'ouverture de la porine OprM, insérée dans une membrane artificielle reconstituée sur une biopuce (Wang, Monlezun et al. 2012). Puis, afin d’étudier cette fois ci, le mécanisme d’ouverture de la porine OprM in vivo, une étude fonctionnelle par complémentation chez Pseudomonas aeruginosa a été initiée. Enfin, dans le cadre d'une collaboration avec l’équipe de P. Plésiat (Laboratoire de Bactériologie, Besançon), deux analyses de mutants cliniques par modélisation ont été réalisées sur le régulateur MexZ de la pompe MexXY/OprM et de la porine d’influx des carbapénèmes OprD. / Pseudomonas aeruginosa is an opportunistic pathogen involved in nosocomial infections. This bacteria has developed various strategies to resist antibiotics treatments, one of them being the activation of membrane efflux pumps. These tripartite systems consist of an OMF (Outer Membrane Factor) family porin, localized in the outer membrane, an active transporter in the inner membrane, belonging to the RND (Resistance Nodulation Division) family and a periplasmic adaptator protein, member of the MFP (Membrane Fusion Protein) family which consolidates the whole complex. Results obtained during this thesis contribute to a better understanding of efflux pumps’ assembly and opening thanks to the development of new research tools borrowed from physic, biochemistry and microbiology. The first study describes the binding stoechiometry of MexA with its cognate partner OprM by Blue Native Polyacrylamide gel Electrophoresis (Ferrandez, Monlezun et al. 2012). Secondly, a study, in collaboration with B. Le Pioufle’s team (ENS Cachan), was dedicated to the electrophysiologic caracterization of OprM opening using a microfluidic device incorporated with a miniaturized artificial bilayer membrane (Wang, Monlezun et al. 2012). Then, to complete this analysis in vivo, in the third part of this thesis, complementation experiments were initiated in a Pseudomonas aeruginosa strain deleted of its chromosomal oprM gene. Finally, in collaboration with P. Plésiat’s team (Laboratoire de Bactériologie, Besançon), modelling of MexZ, the MexXY/OprM pump’s regulator and modelling of the carbapenems’ porin OprD were made in order to link structural modifications to mutations observed in clinical strains.

The necessity of modeling is vital for the purpose of reasoning and diagnosing in complex systems, since the human mind might sometimes have a limited capacity and an inability to be objective. The chain graph (CG) class is a powerful and robust tool for modeling real-world applications. It is a type of probabilistic graphical models (PGM) and has multiple interpretations. Each of these interpretations has a distinct Markov property. This thesis deals with the multivariate regression chain graph (MVR-CG) interpretation. The main goal of this thesis is to implement and evaluate the results of the MVR-PC-algorithm proposed by Sonntag and Peña in 2012. This algorithm uses a constraint based approach used in order to learn a MVR-CG from data.In this study the MRV-PC-algorithm is implemented and tested to see whether the implementation is correct. For this purpose, it is run on several different independence models that can be perfectly represented by MVR-CGs. The learned CG and the independence model of the given probability distribution are then compared to ensure that they are in the same Markov equivalence class. Additionally, for the purpose of checking how accurate the algorithm is, in learning a MVR-CG from data, a large number of samples are passed to the algorithm. The results are analyzed based on number of nodes and average number of adjacents per node. The accuracy of the algorithm is measured by the precision and recall of independencies and dependencies.In general, the higher the number of samples given to the algorithm, the more accurate the learned MVR-CGs become. In addition, when the graph is sparse, the result becomes significantly more accurate. The number of nodes can affect the results slightly. When the number of nodes increases it can lead to better results, if the average number of adjacents is fixed. On the other hand, if the number of nodes is fixed and the average number of adjacents increases, the effect is more considerable and the accuracy of the results dramatically declines. Moreover the type of the random variables can affect the results. Given the samples with discrete variables, the recall of independencies measure would be higher and the precision of independencies measure would be lower. Conversely, given the samples with continuous variables, the recall of independencies would be less but the precision of independencies would be higher.

Orientador: Renivaldo José dos Santos / Resumo: Durante o processo de fabricação dos artefatos de borracha natural (BN), é possível adicionar cargas, podendo ser combinadas em função das propriedades finais pretendidas. Nesse sentido o carbonato de cálcio vem sendo utilizado como carga de enchimento nas formulações com borracha natural, apenas para aumentar o volume da amostra para a mesma quantidade de borracha implementada, buscando apenas a redução do custo final. Devido a demanda industrial, surge a necessidade de investigar a possibilidade de fazer com que uma carga, ora antes utilizada como enchimento, passe a atuar como carga de reforço mecânico, ou seja, a realização de tratamentos superficiais se torna uma possibilidade viável, para que a carga consiga realizar ligações cruzadas entre as cadeias de carbono da BN. Dessa forma, foi proposto neste trabalho o estudo de compósitos de borracha natural tipo crepe claro com carbonato de cálcio ultrafino tratado com 2% do Chartwell C-515.71HR^® para substituição parcial da sílica comercial tratada com silano, buscando identificar a influência deste agente de acoplamento no processo de vulcanização, a fim de melhorar a interação entre a borracha natural e carbonato de cálcio ultrafino. O preparo ocorreu em um misturador aberto de cilindros com a variação de 10 em 10 phr para as cargas, nos híbridos, iniciou-se em 40/00 até 00/40 (sílica/carbonato de cálcio ultrafino), e foi produzida uma amostra controle, com a mesma formulação, porém sem carga, denominada goma pura. Foi po... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: During the manufacturing process of natural rubber (BN) artifacts, it is possible to add loads, which can be combined depending on the desired final properties. In this sense, calcium carbonate has been used as filler in formulations with natural rubber, just to increase the sample volume for the same amount of rubber implemented, seeking only to reduce the final cost. Due to industrial demand, there is a need to investigate the possibility of causing a load, previously used as a filler, to act as a mechanical reinforcement load, that is, the performance of surface treatments becomes a viable possibility, so that the cargo is able to cross-link the BN carbon chains. Thus, the main objective of this work is the study of natural rubber composites of light crepe type with ultrafine calcium carbonate treated with 2% of Chartwell C-515.71HR^® for partial replacement of commercial silica treated with silane, seeking to identify the influence of this coupling agent in the vulcanization process, in order to improve the interaction between natural rubber and ultrafine calcium carbonate. The preparation took place in an open cylinder mixer with a variation of 10 in 10 phr for the loads, in the hybrids, it started in 40/00 until 00/40 (silica / ultrafine calcium carbonate), and a control sample was produced , with the same formulation, but without load, called pure gum. It was possible to replace up to 75% of the silica with treated calcium carbonate, but the best response was to replac... (Complete abstract click electronic access below) / Mestre

Le trafic routier est devenu de plus en plus intense. Une telle situation avec le manque de prudence des piétons constituent deux causes majeures de l’augmentation des accidents routiers. En France, 16% des accidents de la route en 2016 impliquent au moins un piéton et chaque année, environ de 800 piétons sont tués dans un accident de la circulation. De plus, la part des plus de 65 ans dans la mortalité piétonne est en hausse de 13% entre 2014 et 2016. Ainsi, par ce projet de thèse nous proposons une approche probabiliste pour inférer le type de comportement (à risque ou sécurisé) des piétons lors de la traversé de la rue. Cette approche se compose de 2 couches principales : Une couche basse, basée sur les techniques de vision par ordinateur, pour la collecte des paramètres des piétons, du trafic et des aménagements urbains et une couche haute, basée sur le Réseau Bayésien (RB), pour l’inférence du type de comportement. Plusieurs contributions et améliorations sont proposées pour la construction d’une telle approche que ce soit au niveau de la couche basse (techniques de détection et de suivi utilisées) ou au niveau de la couche haute (gestion des incertitudes des capteurs de vision et la mise en relation des paramètres hétérogènes et variées). / Road traffic has become more and more intense. Such as situation with thelack of attention of pedestrians are the two major causes of the increase in road accidents. In France, 16% of road accidents in 2016 involve at least one pedestrian and each year about 800 pedestrians are killed in a traffic accident. In addition, the proportion of pedestrian deaths having over 65 years old is up to 13% between 2014 and 2016. In fact, this thesis proposes a probabilistic approach to recognize pedestrians’ behavior (risky or secure) when crossing the street. This approach consists of two main layers: a low layer, based on computer vision techniques, for collecting pedestrian and traffic parameters and a high layer, based on the Bayesian Network, for behavior prediction. Several contributions and improvements are proposed for the construction of such an approach, whether at the level of the low layer (detection and tracking process) or at the level of the upper layer (management of the uncertainties of the vision sensors and the correlation of heterogeneous and varied parameters).

No description available.

<p>Allergic asthma is a disease involving airway inflammation, commonly linked to allergen exposure. Computed tomography (CT) is used to quantitatively assess changes in density, hence inflammation, in the lung. CT imaging provides the ability to non-invasively and longitudinally study disease progression and evaluate treatment efficacy. The objective of this study was to determine the sensitivity of CT to detect the anti-inflammatory effects of budesonide (BUD) by measuring airway tissue density in a rat model of allergic airway disease.</p> <p>Female<strong> </strong>Brown Norway rats were exposed intratracheally to house dust mite (HDM) extract (250 µg in 100µL saline) or saline control every other day for a total of five administrations (inflammatory phase). ABUD dose and temporal response study was performed usingBUD 0, 10, 100, and 300 µg/kg administered concurrently with HDM for three and six treatments (treatment phase). CT scanning was performed at baseline, post inflammatory phase, and after three and six BUD treatments. From the CT, density was measured in a defined volume of interest surrounding the major airways. Bronchoalveolar lavage (BAL) and histological samples were collected at the same time points.</p> <p>After the inflammatory phase, a significant increase in peribronchial density was found in the HDM group compared to controls. This corresponded to a significant increase in inflammation by histology andBALtotal cell count (TCC), specifically eosinophils. Within the treatment phase after three treatments,BUD100 and 300 µg/kg led to a significant shift in lung density compared to HDM exposure alone, to a state similar to baseline. All BUD treated groups expressed a significant reduction in peribronchial density after six treatments. However, histology andBALTCC only showed a significant decrease in inflammation after six treatments for all three BUD doses.</p> <p>CT densitometry is a sensitive, non-invasive method of evaluating the anti-inflammatory effects of budesonide and can be used for future screening of therapies in allergic lung models. Airway segmentation of CT permits the localized assessment of peribronchial inflammation, while other outcome measurements, such as BAL cytology, provide whole lung assessment which may not accurately reflect important regional changes.</p> / Master of Science (MSc)

Das dreistufige Flüssigsilicierverfahren (LSI) stellt eine Methode dar, siliciumcarbidbasierte faserverstärkte Keramiken herzustellen. Ausgangspunkt ist ein faserverstärkter Kunststoff, der über Pyrolyse (Konvertierung des Matrixpolymers in Kohlenstoff) und Silicierung (Siliciuminfiltration und Reaktion zu Siliciumcarbid) keramisiert wird. In der vorliegenden Arbeit werden die Matrix mittels der verwendeten Matrixpolymere (Matrixdesign) und das Faser/Matrix-Interface durch das Aufbringen von Faserbeschichtungen (Interfacedesign) definiert gestaltet. Die in der Arbeit eingesetzten Matrixpolymere beeinflussen durch eine unterschiedliche Poren- und Rissbildung in der Kohlenstoffmatrix die Siliciuminfiltration und die damit verbundene Siliciumcarbidbildung. Die Matrixpolymere erzeugen einerseits eine C-SiC-Dualphasenmatrix, wie diese bei den C/C-SiC-Verbunden angestrebt wird. Andererseits kann eine weitestgehend einphasige SiC-Matrix eingestellt werden, welche für die Herstellung von SiC/SiC-Verbunden interessant ist. Bei diesen Verbundwerkstoffen ist eine zusätzliche Faserbeschichtung entscheidend, um die Faser/Matrix-Bindung zu reduzieren und die Fasern vor dem Siliciumangriff während der Herstellung zu schützen. Als Faserbeschichtung werden eine BNx-Schicht und eine SiNx-Schicht entwickelt, die in einer BNx/SiNx-Doppelschicht kombiniert werden. Die Schichtherstellung erfolgt mittels chemischer Gasphasenabscheidung (CVD) auf einem kommerziellen SiC-Fasergarn (Tyranno SA3). Die amorphe BNx-Schicht ist innerhalb des Fasergarnes sehr homogen. Dahingegen besitzt die amorphe SiNx-Schicht einen Gradient in der Schichtdicke sowie in der chemischen Zusammensetzung. Bei der thermischen Auslagerung bleibt die BNx-Schicht stabil. Die SiNx-Schicht kristallisiert und es bilden sich Poren und Siliciumausscheidungen innerhalb der Schicht. Zudem entstehen teilweise Risse und Schichtabplatzungen. Weitere alternative Schichtkonzepte werden vorgeschlagen. / The liquid silicon infiltration (LSI) process is used to produce silicon carbide (SiC) based fiber reinforced ceramics and consists of three stages. Starting point is a fiber reinforced plastic, which is ceramized by means of pyrolysis (conversion of the matrix polymer to carbon) and siliconization (silicon infiltration and reaction to form silicon carbide). In the present work, the matrix and the fiber/matrix interface are designed by utilizing special matrix polymers and fiber coatings, respectively. The used matrix polymers lead to different pore and crack formation in the carbon matrix affecting the liquid silicon infiltration and the silicon carbide formation. The polymers not only create a dual phase C-SiC matrix, which is aspired for the production of C/C-SiC composites, but also form a single phase SiC matrix favorable for the SiC/SiC composite production. An additional coating of the fibers for these composite materials is crucial to reduce the fiber/matrix bonding and to protect the fibers from corrosive silicon attack. Separate BNx and SiNx single coatings are developed, which are combined to a double coating. The coating process is realized by chemical vapor deposition (CVD) on a commercial SiC fiber yarn (Tyranno SA3). The amorphous BNx coating is very uniform within the yarn, whereas the amorphous SiNx coating is characterized by a gradient regarding the layer thickness as well as the chemical composition. During the high temperature heat treatment the BNx coating remains stable. The SiNx coating crystallizes and pores as well as silicon precipitations are formed. Moreover, the coating partially ruptures. In this work, some additional alternative coating concepts are also proposed.

The two related putative cytochrome c oxidase (COX) assembly factors HCC1 and HCC2 from Arabidopsis thaliana are Homologs of the yeast Copper Chaperones Sco1p and Sco2p. The hcc1 null mutation was previously shown to be embryo lethal while the disruption of the HCC2 gene function had no obvious effect on plant development, but increased the expression of stress-responsive genes. Both HCC1 and HCC2 contain a thioredoxin domain, but only HCC1 carries a Cu-binding motif also found in Sco1p and Sco2p. In order to investigate the physiological implications suggested by this difference, various hcc1 and hcc2 mutants were generated and analyzed. The lethality of the hcc1 knockout mutation was rescued by complementation with the HCC1 gene under the control of the embryo-specific promoter ABSCISIC ACID INSENSITIVE 3. However, the complemented seedlings did not grow into mature plants, underscoring the general importance of HCC1 for plant growth. The HCC2 homolog was shown to localize to mitochondria like HCC1, yet the function of HCC2 is evidently different, because two hcc2 knockout lines developed normally and exhibited only mild growth suppression compared with the wild type (WT). However, hcc2 knockouts were more sensitive to UV-B treatment than the WT. Complementation of the hcc2 knockout with HCC2 rescued the UV-B-sensitive phenotype. In agreement with this, exposure of wild-type plants to UV-B led to an increase of HCC2 transcripts. In order to corroborate a function of HCC1 and HCC2 in COX biogenesis, COX activity of hcc1 and hcc2 mutants was compared. While the loss of HCC2 function had no significant effect on COX activity, the disruption of one HCC1 gene copy was enough to suppress respiration by more than half compared with the WT. Therefore, we conclude that HCC1 is essential for COX function, most likely by delivering Cu to the catalytic center. HCC2, on the other hand, seems to be involved directly or indirectly in UV-B-stress responses.

The two related putative cytochrome c oxidase (COX) assembly factors HCC1 and HCC2 from Arabidopsis thaliana are Homologs of the yeast Copper Chaperones Sco1p and Sco2p. The hcc1 null mutation was previously shown to be embryo lethal while the disruption of the HCC2 gene function had no obvious effect on plant development, but increased the expression of stress-responsive genes. Both HCC1 and HCC2 contain a thioredoxin domain, but only HCC1 carries a Cu-binding motif also found in Sco1p and Sco2p. In order to investigate the physiological implications suggested by this difference, various hcc1 and hcc2 mutants were generated and analyzed. The lethality of the hcc1 knockout mutation was rescued by complementation with the HCC1 gene under the control of the embryo-specific promoter ABSCISIC ACID INSENSITIVE 3. However, the complemented seedlings did not grow into mature plants, underscoring the general importance of HCC1 for plant growth. The HCC2 homolog was shown to localize to mitochondria like HCC1, yet the function of HCC2 is evidently different, because two hcc2 knockout lines developed normally and exhibited only mild growth suppression compared with the wild type (WT). However, hcc2 knockouts were more sensitive to UV-B treatment than the WT. Complementation of the hcc2 knockout with HCC2 rescued the UV-B-sensitive phenotype. In agreement with this, exposure of wild-type plants to UV-B led to an increase of HCC2 transcripts. In order to corroborate a function of HCC1 and HCC2 in COX biogenesis, COX activity of hcc1 and hcc2 mutants was compared. While the loss of HCC2 function had no significant effect on COX activity, the disruption of one HCC1 gene copy was enough to suppress respiration by more than half compared with the WT. Therefore, we conclude that HCC1 is essential for COX function, most likely by delivering Cu to the catalytic center. HCC2, on the other hand, seems to be involved directly or indirectly in UV-B-stress responses.