Дисертації з теми "Réseau de cellules programmables"
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Tanguy, Sébastien. "Test et testabilité des FPGA hiérarchiques à base de cellules mémoires SRAM." Montpellier 2, 2006. http://www.theses.fr/2006MON20050.
Bricas, Gaëtan. "Radiation reliability analysis of FPGA-based systems : testing methodologies and analytical approaches." Electronic Thesis or Diss., Université de Montpellier (2022-....), 2022. http://www.theses.fr/2022UMONS070.
This work focuses on testing methodologies to analyze the radiation sensitivity of FPGA-based systems. Due to their flexibility, the reliability analysis on these components is a challenging task as the radiation sensitivity is entirely conditioned by the implemented system. Indeed, it depends on the one hand on the intrinsic sensitivity of the component (to both TID and SEEs) and, on the other hand, on the way the different induced perturbations can impact the operation of the implemented system. State-of-the-art methodologies have shown a number of limitations in bridging the intrinsic sensitivity of the FPGA and the one of the implemented systems. The objective of this thesis is to improve radiation testing methodologies to overcome these limitations.Concerning TID effects, a new testing methodology is proposed. Its main contribution is to extend the evaluation of parametric degradations to all logical and routing resources of the component. For this purpose, specific benchmarking structures have been developed to measure the propagation delay deviation of each type of logical and routing resource. A new technique to measure the propagation delay in real time and with limited external instrumentation is also proposed. X-ray radiation tests have been performed on three FPGA families to highlight the benefits of this methodology.As for SEE, the proposed testing methodology lies between the two traditional accelerated particle beam testing approaches (primitive level testing and final application testing) by proposing a sensitivity evaluation at a higher level of granularity. The basic idea is to instantiate a set of dedicated benchmarking structures, simple enough to provide a good testability (low error masking, traversable state spaces) while sufficiently complex to provide a good representativity of the circuits effectively implemented on FPGAs. The benchmarks selected in this study are based on arithmetic operations. By using different implementations of the same arithmetic functions with a large diversity in the circuit parameters, and in the use of resources, the radiation tests fulfill a multifaceted purpose. First, the test results provide extensive information to identify and understand the different failure mechanisms and their predominance; second, it allows to qualitatively evaluate the impact of different types of resources on the global system sensitivity and to quantitatively compare the sensitivity of different implementations of the same logic function and the effectiveness of mitigation solutions. Finally, it provides a set of guidelines for designers to improve the reliability of FPGA-based systems. Several neutron and proton beam tests have been performed to demonstrate the advantages of this approach.The main limitation of radiation testing lies with the difficulty to extrapolate the results of tests performed with a given implemented circuit to estimate the sensitivity of any other circuit. To address these limitations, a new software-based approach has been developed to estimate the susceptibility of circuits implemented on SRAM based FPGA to configuration memory corruptions. This analytical approach uses the physical netlist of the circuit and explores the different nodes and logical resources that compose it to extract all the configuration bits that are critical for the system operation. The main contribution of this approach is to take into account the workload of the circuit, extracted from logic simulation, to analyze the propagation of errors and thus filter among the set of potentially critical configuration bits, those that actually modify the output signals of the system. The efficiency of this approach is validated through fault injection and proton experiment
Bruchon, Nicolas. "Evaluation, validation et design de cellules hybrides CMOS-technologie non-volatile émergente pour une architecture reconfigurable à grain fin." Montpellier 2, 2007. http://www.theses.fr/2007MON20233.
On a very competitive marketplace, time to market of electronic and microelectronic chips is a critical point. Using FPGAs instead of ASICs avoid place and route, layout, mask confection and foundry steps but power consumption and area performances are not optimized. The aim here is to propose an FPGA ciruit featuring non volatile configuration memory. Different emerging non volatile memories and their compatibility with classical CMOS circuits are presented. Integration of these technologies in a programmable architecture context is discussed. A standard structure (RSRAM) is proposed to convert information from their physical into electrical form. This RSRAM is derived under different forms adapted to the writing circuits of the different non volatile memory technologies. This structure provides the circuit with dynamical and sadowed reconfiguration capabilities. An FPGA with magnetic non volatile configuration memory is proposed. This circuit has been simulated and will soon be characterized
Westrelin, Roland. "Propositions autour de l'architecture logicielle des interfaces réseau programmables." Lyon 1, 2001. http://www.theses.fr/2001LYO10178.
Guerre, Alexandre. "Approche hiérarchique pour la gestion dynamique des tâches et des communications dans les architectures massivement parallèles programmables." Paris 11, 2010. http://www.theses.fr/2010PA112102.
Nowadays, embedded systems have many uses like cell phones, GPS, etc. . Moreover, all these applications become complex. Hence, embedded world needs powerful and flexible processors able to manage the execution of dynamic applications. Mono-processors reach their limits and cannot provide enough computing power with the respect of embedded constraints. To solve this problem, embedded systems use multi-core processors. This thesis focuses on the problem of communication into many-core processors and the management of thousands of tasks on this kind of architecture. It presents an execution model and a many-core architecture able to respect embedded constraints. The architecture is composed of clusters of processors, and a hierarchical control to manage the execution of tasks and communications. The application is cut into Iinear task groups. These groups are dynamically dispatched on the architecture. We demonstrate that a hierarchical approach can provide a significant benefit in term of transistor efficiency in embedded systems
Chang, Eric Ty. "Etude d'une interface de programmation des services du réseau intelligent basée sur des composants reutilisables." Versailles-St Quentin en Yvelines, 1996. http://www.theses.fr/1996VERS004V.
Bonté, Eric. "Calcul des extensions dans les théories de défauts en réseau : Application au raisonnement à profondeur variable." Paris 13, 1992. http://www.theses.fr/1992PA132015.
Babba, Belgacem. "Synthèse optimisée sur les réseaux programmables de la famille Xilinx." Phd thesis, Grenoble INPG, 1995. http://tel.archives-ouvertes.fr/tel-00346062.
Kebe, Ahmed. "Implémentation sur FPGA de l'algorithme MUSIC sur antenne-réseau expérimentale à 10 GHz." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27285.
The techniques of Directions of Arrival (DOA) are a promising way to increase the capacity of systems and telecommunications services to better estimate the mobile-radio channel. They allow precise monitoring of cellular users to orient the antenna beams at them. Therefore, in this context, this paper describes step by step implementation of the high-level algorithm MUSIC (Multiple SIgnal Classification) on an FPGA platform to determine in real time the angle of arrival of one or incident sources to an antenna array. The Rapid Control Prototyping (RCP) with the tools of XilinxTM System generator (XSG) and MBDK (Model Based Design Kit) of NutaqTM is the development concept used. This concept is based on a high level programming code through models, to automatically generate a low-level code. A special attention is devoted to the method chosen to solve the eigenvalues decomposition problem for the complex autocorrelation matrix by Jacobi algorithm. The architecture designed implementing it in FPGA (Field Programmable Gate Array) is detailed. Furthermore, it is proved that MUSIC can perform an interesting estimate of the position of the sources without prior calibration of the antenna array. Thus, the calibration technique G matrix used in this project is presented, in addition to the implementation model. Finally, the experimental results of the system tested in a real environment in the presence of one source then two highly correlated sources are illustrated and analyzed.
Lattard, Didier. "Architecture massivement parallèle : un réseau de cellules intégré pour la reconstruction d'images." Phd thesis, Grenoble INPG, 1989. http://tel.archives-ouvertes.fr/tel-00335786.
Bosco, Gilles. "Synthèse et décomposition technologique sur réseaux programmables et ASICs." Phd thesis, Grenoble INPG, 1996. http://tel.archives-ouvertes.fr/tel-00346210.
Belrhiti, Alaoui Mohammed. "Nouvelles Méthodes de Synthèse Logique et Application aux Réseaux Programmables." Phd thesis, Grenoble INPG, 1996. http://tel.archives-ouvertes.fr/tel-00346229.
Cornu-Emieux, Renaud. "Réseau de cellules intégré : étude d'architectures pour des applications de CAO de VLSI." Phd thesis, Grenoble INPG, 1988. http://tel.archives-ouvertes.fr/tel-00328650.
Soni, Hardik. "Une approche modulaire avec délégation de contrôle pour les réseaux programmables." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4026/document.
Network operators are facing great challenges in terms of cost and complexity in order to incorporate new communication technologies (e.g., 4G, 5G, fiber) and to keep up with increasing demands of new network services to address emerging use cases. Softwarizing the network operations using SoftwareDefined Networking (SDN) and Network Function Virtualization (NFV) paradigms can simplify control and management of networks and provide network services in a cost effective way. SDN decouples control and data traffic processing in the network and centralizes the control traffic processing to simplify the network management, but may face scalability issues due to the same reasons. NFV decouples hardware and software of network appliances for cost effective operations of network services, but faces performance degradation issues due to data traffic processing in software. In order to address scalability and performance issues in SDN/NFV, we propose in the first part of the thesis, a modular network control and management architecture, in which the SDN controller delegates part of its responsibilities to specific network functions instantiated in network devices at strategic locations in the infrastructure. We have chosen to focus on a modern application using an IP multicast service for live video streaming applications (e.g., Facebook Live or Periscope) that illustrates well the SDN scalability problems. Our solution exploits benefits of the NFV paradigm to address the scalability issue of centralized SDN control plane by offloading processing of multicast service specific control traffic to Multicast Network Functions (MNFs) implemented in software and executed in NFV environment at the edge of the network. Our approach provides smart, flexible and scalable group management and leverages centralized control of SDN for Lazy Load Balance Multicast (L2BM) traffic engineering policy in software defined ISP networks. Evaluation of this approach is tricky, as real world SDN testbeds are costly and not easily available for the research community. So, we designed a tool that leverages the huge amount of resources available in the grid, to easily emulate such scenarios. Our tool, called DiG, takes into account the physical resources (memory, CPU, link capacity) constraints to provide a realistic evaluation environment with controlled conditions. Our NFV-based approach requires multiple application specific functions (e.g., MNFs) to control and manage the network devices and process the related data traffic in an independent way. Ideally, these specific functions should be implemented directly on hardware programmable routers. In this case, new routers must be able to execute multiple independently developed programs. Packet-level programming language P4, one of the promising SDN-enabling technologies, allows applications to program their data traffic processing on P4 compatible network devices. In the second part of the thesis, we propose a novel approach to deploy and execute multiple independently developed and compiled applications programs on the same network device. This solution, called P4Bricks, allows multiple applications to control and manage their data traffic, independently. P4Bricks merges programmable blocks (parsers/deparsers and packet processing pipelines) of P4 programs according to processing semantics (parallel or sequential) provided at the time of deployment
Objois, Philippe. "Réseau de cellules intégré : mécanisme de communication inter-cellulaire et application à la simulation logique." Phd thesis, Grenoble INPG, 1988. http://tel.archives-ouvertes.fr/tel-00328188.
Collombet, Samuel. "Investigation du réseau de régulation contrôlant la spécification et la reprogrammation des cellules du sang." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEE032/document.
Immune cells arise from a common set of hematopoietic stem cells, which differentiate hierarchically into the myeloid and lymphoid lineages. This process is tightly regulated by an intertwined network of transcription and epigenetic factors, which control both the activation and repression of gene programs, to ensure cell commitment. However, recent work on cellular reprogramminghas shown that the ectopic expression of some specific factors can enforce the trans-differentiation of committed cells. The transcription factor C/EBPa can induce the reprogramming of B-cells into macrophages. Furthermore, a pulse of Cebpa expression in B cells followed by the expression of the four transcription factors Oct4-Sox2-Klf4-cMyc leads to an extremely fast and efficient reprogramming into induced pluripotent stem cells. Despite the many data we have on the molecular mechanisms by which specific genes are regulated, we are still lacking a global understanding of the interplay between these factors and how theycontrol cell fate. In order to decipher the molecular regulatory network controlling immune cell specification and their reprogramming, I have combined a variety of high-throughput methods to measure changes in gene expression and epigenetic regulation during B cells reprogramming. I have revealed the interplay between different transcription factors at enhancers regulating genes of the different programs (B cells, macrophages and pluripotent cells) and identified epigenetic regulators forming complexes and controlling enhancers activities (such as Lsd1, Hdac1, Brd4 and Tet2) and consequently regulating cell fate. Finally, I integrated these data together with published data, in a computational model of the regulatory network controlling the specification of B-cells and macrophages from multipotent progenitors. I used both analytic tools (stable states analysis) and simulations (logical asynchronous simulations, continuous time Markov chains) to study in silico differentiation and reprogramming.These analyses have revealed previouslyunknown transcriptional regulations, which weconfirmed experimentally, and allowed us to get abetter understanding of the regulatory circuitscontrolling cell fate commitment
Collombet, Samuel. "Investigation du réseau de régulation contrôlant la spécification et la reprogrammation des cellules du sang." Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEE032.
Immune cells arise from a common set of hematopoietic stem cells, which differentiate hierarchically into the myeloid and lymphoid lineages. This process is tightly regulated by an intertwined network of transcription and epigenetic factors, which control both the activation and repression of gene programs, to ensure cell commitment. However, recent work on cellular reprogramminghas shown that the ectopic expression of some specific factors can enforce the trans-differentiation of committed cells. The transcription factor C/EBPa can induce the reprogramming of B-cells into macrophages. Furthermore, a pulse of Cebpa expression in B cells followed by the expression of the four transcription factors Oct4-Sox2-Klf4-cMyc leads to an extremely fast and efficient reprogramming into induced pluripotent stem cells. Despite the many data we have on the molecular mechanisms by which specific genes are regulated, we are still lacking a global understanding of the interplay between these factors and how theycontrol cell fate. In order to decipher the molecular regulatory network controlling immune cell specification and their reprogramming, I have combined a variety of high-throughput methods to measure changes in gene expression and epigenetic regulation during B cells reprogramming. I have revealed the interplay between different transcription factors at enhancers regulating genes of the different programs (B cells, macrophages and pluripotent cells) and identified epigenetic regulators forming complexes and controlling enhancers activities (such as Lsd1, Hdac1, Brd4 and Tet2) and consequently regulating cell fate. Finally, I integrated these data together with published data, in a computational model of the regulatory network controlling the specification of B-cells and macrophages from multipotent progenitors. I used both analytic tools (stable states analysis) and simulations (logical asynchronous simulations, continuous time Markov chains) to study in silico differentiation and reprogramming.These analyses have revealed previouslyunknown transcriptional regulations, which weconfirmed experimentally, and allowed us to get abetter understanding of the regulatory circuitscontrolling cell fate commitment
Aouadj, Messaoud. "AirNet, le modèle de virtualisation « Edge-Fabric » comme plan de contrôle pour les réseaux programmables." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30138/document.
The work of this thesis falls within the general context of software-defined networking (SDN). This new paradigm is one of the most significant initiatives to enable networks programmability or, in other words, to make current networks easier to configure, test, debug and evolve. Within an SDN ecosystem, the Northbound interface is used by network administrators to define policies and to program the control plane, it thus represents a major challenge. Ideally, this northbound interface should allow administrators to describe, as simply as possible, network services and their interactions, rather than specifying how and on what physical device they need to be deployed. Current related works show that this can be partly achieved through virtualization solutions and high-level domain specific languages (DSL). The objective of this thesis is to propose a new Northbound interface which will, on the one hand, rely on network virtualization and, on the other hand, expose its services as a domain specific programming language. Currently, several languages that include network virtualization solutions exist. Nevertheless, we believe that the abstract models they are using to build virtual networks remain inadequate to ensure simplicity, modularity and flexibility of virtual topologies and control programs. In this context, we propose a new network control language named AirNet. Our language is built on top of an abstraction model whose main feature is to provide a clear separation between edge and core network devices. This concept is a well-known and accepted idea within the network designer community. The originality of our contribution is to lift up this concept at the virtual control plane, not limiting it solely at the physical plane. Thus, logical boundaries between different types of policies will exist (control and data functions vs. transport functions), ensuring modularity and reusability of the control program. Moreover, in the proposed approach, the definition of the virtual network and policies is totally dissociated from the target physical infrastructure, promoting the portability of control applications. An implementation of the AirNet language has also been done. This prototype includes in particular a library that implements the primitives and operators of the language, and a hypervisor that achieves the composition of the control policies on the virtual network, and their mapping on the physical infrastructure. In order to rely on existing SDN controllers, the hypervisor includes integration modules for the POX and RYU controllers. An experimental validation has been also conducted on different use cases (filtering, load balancing, dynamic authentication, bandwidth throttling, etc.), whose results demonstrate the feasibility of our solution. Finally, performance measurements have shown that the additional cost brought by this new abstraction layer is perfectly acceptable
Vailhe, Bruno. "Réorganisation in vitro des cellules endothéliales sur matrice de fibrine en un réseau de pseudo-capillaires." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10235.
Balland, martial. "Etude microrhéologique du réseau d'actine de cellules en culture en présence de facteurs biochimiques modifiant sa dynamique." Phd thesis, Université Paris-Diderot - Paris VII, 2004. http://tel.archives-ouvertes.fr/tel-00009607.
Balland, Martial. "Etude microrhéologique du réseau d'actine de cellules en culture en présence de facteurs biochimiques modifiant sa dynamique." Paris 7, 2004. http://www.theses.fr/2004PA077201.
Ein-Eli, Noémie. "Migration de cellules tumorales mammaire sur réseau en 3 Dimension et Mécanismes physiques de la protéolyse matricielle." Thesis, Cergy-Pontoise, 2014. http://www.theses.fr/2014CERG0688/document.
We study the migration and proteolysis of the extracellular matrix in breast cancer. For this, we set up two model systems. The first is based on a reconstituted basement membrane and allows the evaluation of invasive potential tumor cell lines. We show that cancer cells migrate differently across the gel to form clusters of variable size directly correlates with their invasiveness. In our system, only the migration of mesenchymal type is used by the cells. This type of movement is directly dependent proteases secreted by the cells. We therefore measured the synthesis at the transcriptional level of the enzyme class mainly involved in tumor dissemination, the matrix metalloproteases (MMPs). We were able to show that the expression of 3 MMPs is correlated with migratory capacity of cells, therefore their invasive potential. The physical process by which enzymes degrade the matrix is very little studied at the experimental level. The second system we use is based on a model of connective matrix mainly composed of collagen type I. We use gelatin for the study of protein gels proteolysis by different classes of proteases. Based on the study of gels enzymatic solubilization by a- chymotrypsin, proteinase K and papain, we show that there are distinct mechanisms of degradation. The first mechanism is abnormal whose kinetic is limited by enzyme diffusion, and the second is Brownian and the kinetic is reaction limited. The second mechanism depends directly on electrostatic interactions between enzyme and gel. We observe for two enzymes that the evolution of degradation time but also the degradation kinetics depend on the concentration of protein in gels
Gaston, Cécile. "Rôle d'EpCAM sur l'activité du réseau d'actomyosine et impact sur le maintien de l'organisation épithéliale." Thesis, Université de Paris (2019-....), 2019. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=3982&f=25561.
Epithelial integrity relies on the correct distribution and activity of the actomyosin cytoskeleton to maintain cell shape and junctional adhesion during homeostasis, and even more importantly, under stress. The actomyosin apparatus is regulated by many different signalling pathways targeting either the actin dynamics or myosin activation, one of which is dependent on the small GTPase RhoA. EpCAM (Epithelial Cell Adhesion Molecule) was primarily described as a Ca2+-independent cell-cell adhesion molecule that is specific of epithelia, although recent analyses tend to challenge this statement. In this work, we report the involvement of EpCAM in epithelial contractility regulation and its importance for the maintenance of cell polarity. In a first study, we show that EpCAM is required for proper distribution and activity of Myosin-II that controls junctional integrity and the maintenance of apico-basal polarity in an epithelial monolayer. EpCAM depletion leads to an atypical polarity loss with devastating effects on the epithelium integrity, worsening when the epithelial monolayer is subjected to mechanical stress. In a second study, we tackled the issue of EpCAM depletion on the actomyosin apparatus in relation to cell-substrate adhesion and cell migration. We demonstrated that EpCAM is involved in the control of active RhoA recycling, allowing for the correct organization of the actomyosin apparatus and the establishment of front-rear polarity. Surprisingly, our results showed that these effects were cell-autonomous and did not require the presence of cell-cell junctions. We propose that EpCAM function as a cell adhesion molecule is revised to a more general role as a cell contractility regulator. These results bring new light on the spatio-temporal regulation of RhoA-dependent contractility, and its effects on epithelial integrity
Bertot, Charlotte. "Le rôle des cellules microgliales dans le développement des circuits neuronaux." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0414/document.
Microglial cells, the resident macrophages of the central nervous system, were mainly studied for their role in pathological conditions, but they recently appeared to be involved in synaptic development and circuits formation during postnatal period. During this critical period, microglial cells colonize the central nervous system and interact with other cell types, including neurons. A specific way of communication between neurons and microglia involves neuronal released fractalkine (CX3CL1) and its specific microglial receptor CX3CR1. CX3CR1 KO mice contributed to unclose microglial role during development. Indeed, CX3CR1 ablation alters microglia distribution in the brain, and it affects glutamatergic transmission and synapse maturation. However, these effects seem to be transient and brain region specific and their mechanisms are poorly understood. Furthermore, some effects observed in juvenile or adult mice may have origin during development, when neuronal connections are established. GABA plays a fundamental role in this process since it is excitatory The influence of neuron.microglia interaction on neuronal activity in the hippocampus during this period is poorly understood. In particular, nothing is known on GABAergic activity, known to be synaptogenic during this period My PhD project aimed at investigating how the signaling fractalkine pathway impacts microglial coloniation of the hippocampus and neuronal activity during the first two postnatal weeks. Our results indicate that in CX3XR1KO mice there is a reduction in the density of microglial cells at P7-P9 in the CA3 hippocampal area, accompanied at P7 by a significant reduction of frequency of Giant Depolarizing Potentials (GDPs), a network activity involved in hippocampal synapse formation and maturation Furthermore, despite no overall difference in glutamatergic or GABAergic synaptic activity, GABAergic events display a subpopulation of larger events, and the kinetics was slightly faster. Thus, the disruption of the specific neuronal.microglia signaling pathway on one hand impacts the microglia coloniation of the hippocampus and on the other hands affects specifically neuronal network activity during a time window critical for the establishment of neuronal connections
Mener, Simon. "Conception d'une cellule déphaseuse pour réseau réflecteur reconfigurable à deux polarisations circulaires indépendantes." Phd thesis, INSA de Rennes, 2013. http://tel.archives-ouvertes.fr/tel-00957819.
Mener, Simon. "Conception d’une cellule déphaseuse pour réseau réflecteur reconfigurable à deux polarisations circulaires indépendantes." Thesis, Rennes, INSA, 2013. http://www.theses.fr/2013ISAR0028/document.
This thesis done in partnership with the French Space Agency (CNES) and the French Defense Agency (DGA) is placed in a very active international context on reflectarrays antennas. A reflectarray consists of a primary source located above microstrip elements on a grounded substrate. The microstrip elements are designed to reradiate the incident wave. A reconfiguration of the radiation pattern can be electronically achieved by introducing switches in each element. In this context, for space applications in X-band, the objective of this thesis is to propose a dual-circular polarization (CP) unit-cell able to separate at the same frequency, the two incident circular polarizations. This unit-cell, made of two layers with reconfigurable capabilities, is based on a circular polarization selective surface (CPSS) and on a single polarization cell. After intensive electromagnetic simulations, the unit-cell in dual-circular polarization with reconfigurable capabilities has been experimentally validated using a specific waveguide measurement. In fact, the unitcell reflects independently and simultaneously the two incidents circular polarizations for a phase resolution around 2 bits in LHCP and in RHCP. A feasibility study of the reconfigurable cell was also carried out to identify the most relevant technologies. Then, a reflectarray in X-band has been designed, fabricated and measured. Made up of 97 cells, it has demonstrated the potentialities of the structure for a realistic space application: scan angle up to 26 °, bandwidth of 800MHz in X-band, cross-polarization rejection>20dB and good polarization purity (AR<2dB). This is the first time that a dual circular polarization reflectarray with reconfigurable capabilities has been validated with the unique capability to reflect independently and simultaneously the two incident circular polarization at the same frequency
Créquit, Perrine. "Méta-analyse en réseau cumulative et dynamique." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB085.
Systematic reviews are essential tools to synthesize available evidence for therapeutic evaluation. Multiple treatments are now frequently available for a given condition. Patients and physicians want to know which one is the best among all treatments. Thus we need to retrieve and synthesize all available evidence across all treatments and furthermore to maintain it updated when new evidence and new treatments become available. Our objective was to evaluate the limits of the current ecosystem of evidence synthesis and to develop an alternative methodology. We have first assessed the capacity of systematic reviews to cover all available evidence of multiple treatments. We took the example of second-line treatments of advanced non-small cell lung cancer with EGFR wild-type or unknown status. We have shown that the 29 systematic reviews published in this condition up to 2015, considered collectively, failed to provide a complete and updated synthesis of all available evidence. Almost 40% of the 77 trials, of the 45 treatments, of the 54 treatment comparisons and of the 28,636 patients were always missing from systematic reviews. We have discussed the reasons why the ecosystem of evidence synthesis fails to encompass all available evidence. We then developed a new paradigm to synthesize evidence over time called live cumulative network meta-analysis. This new concept consists in switching from a series of standard meta-analyses to a single network meta-analysis covering all treatments and systematically updated as soon as the results of a new trial become available. Live cumulative network meta-analysis is initiated with a network meta-analysis which is iteratively updated. We have described the methodological steps, developed the protocol of a proof-of-concept study applied to second-line treatments of advanced non-small cell lung cancer. Finally, we have performed the initial network meta-analysis in this condition. We have included 98 trials including 34,179 patients and assessing 60 treatments. We have shown that nivolumab was more effective in term of overall survival compared to docetaxel HR=0.68 (IC95% 0.55-0.83), to pemetrexed HR=0.65 (0.5-0.83), to erlotinib HR=0.66 (0.51-0.84) and to gefitinib HR=0.65 (0.51-0.82). Similar results were found with pembrolizumab. In progression free survival, nivolumab had a more important treatment effect compared to the four recommended treatments. Live cumulative network meta-analysis should become a paradigmatic shift for systematic reviews and meta-analysis in order to improve medical decision making
Khoyratee, Farad. "Conception d’une plateforme modulable de réseau de neurones biomimétiques pour l’étude des maladies neurodégénératives." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0351.
Neuroscience has been the subject of many studies and has seen new fields of research emerge where technology and biology can be used to find solutions to understand and cure neurological diseases. These illness affect millions of people around the world. The World Health Organization (WHO) predicts a 3 fold increase in the number of patients in the next 30 years.Advances in neuroscience have led to the development of models describing the physiology of neurons and also methods of hardware implementation of these models. Among these methods, neuroprosthesis are devices for restoring certain neuronal functions through communication with the nervous system.This thesis work show that the realization of the biomimetic system was carried out thanks to digital components such as Field Programmable Gate Array (FPGA) which allows to benefit from the flexibility and speed of prototyping of these technologies. The real-time platform of biologically realistic neural networks developed is configurable. It becomes a neuro-computational tool allowing the realization of bio-hybrid experiments for the study of the behavior of the nervous system and more particularly of the neurodegenerative diseases.This work was placed in a larger context. The FPGA digital operator library developed for the platform has been reused for the study of dynamics similar to neural networks such as biochemical network simulation or combinatorial optimization problem solving
Christophe, Elodie. "Rôle des interneurones de la couche I et des cellules pyramidales de la couche V dans le réseau néocortical." Paris 6, 2004. http://www.theses.fr/2004PA066057.
Le, Droguen Pierre-Marie. "Rôle du réseau de microtubules lors de la morphogénèse du système trachéal dans l'embryon de drosophile." Paris 7, 2013. http://www.theses.fr/2013PA077162.
Epithelium remodelling is an essential mechanism for organogenesis and requires changes of cell shape and position while maintaining contact with each other. Celle shaping is accurately regulated by its polarity. Polarity is an essantial feature of cells, implying the segregation of molecules in space and time, which is based in part on the cytoskeleton of microtubules (MTs). MTs are highly dynamic and polarised structures which notably assume vesicular transport. To better understand the role of MTs during epithelial morphogenesis, I studied the mechanisms regulating the organisation of the MT network and determined its functional relevance on epithelial polarity. I used the tracheal system in drosophila embryo as a model of tubular epithelium allowing me to investigate 3D organ development. I contributed to reveal a re-localisation of the material of MT nucleation from the centrosome towards the apical part of tracheal cells which is essential for the tracheal organogenesis. I developed an approach of quantitative analysis of confocal acquisitions and demonstated that MTs are critical for the tracheal morphogenesis. I showed they are involved in the regulation of adherens junctions (AJs) which are required for maintaining cellular contacts. My work uncovers a MT-dependent apical restriction of recycling endosomes that promotes adhesion by sustaining AJ compenents Par-3 and E-cadhesion at AJs. Altogether my thesis show the functional interaction between MTs, vesicular trafficking and the regulation of cellular adhesions
Yann, Clément. "Modélisation électromagnétique de cellules actives environnées : application à l'analyse et la synthèse d'une antenne reflectarray à balayage électronique." Rennes, INSA, 2012. https://tel.archives-ouvertes.fr/tel-00781799.
Reflectarray antenna is a promising solution for space communications and radar applications as it combines attractive features of reflector and array antennas. A reflectarray consists of an array of reflecting cells fed by a horn antenna. Each cell introduces an appropriate phase-shift to the incident wave to steer the main beam in a desired direction. Thanks to the primary feed horn, the complex feed network that characterizes phased array antennas is not required anymore. This thesis focuses on the electromagnetic simulation of reconfigurable reflectarrays (RRA) with electronic beam scanning. The current simulation approaches of RRA ignore or approximate the mutual coupling effects between cells which lead to prediction errors on the radiation pattern. The simulation of RRA generates complex treatments and requires significant computation time and memory resources. The simulation challenge is to reduce the computation time while preserving high accuracy so as to optimize the radiation performances and the design process. In this context, two innovative methods have been proposed: - The first method is dedicated to the thorough analysis of the field radiated by the reflectarray. It combines the 'surrounded-element' approach developed by M. -A. Milon and the compression technique which is generally used for circuit analysis. The extension of the compression technique to compute the field radiated by active cells in their actual environment is the key contribution of the method. The second method computes the phase responses of an active cell taking into account mutual coupling from the surrounded cells. The responses are used to select the optimal configuration of the states of the cells so as to provide a pencil beam in a specific direction. Different test cases of active arrays with PIN diodes are considered to demonstrate the performance and the applicability of the two methods for solving the electromagnetic problems associated with RRA. The validation procedure has proved that the methods offer an interesting alternative to classical approaches. The methods are applied to an X-band RRA designed by Thales Systèmes Aéroportés and the space agency CNES. This study has shown that the two methods meet the scientific and industrial objectives in terms of prediction accuracy and short computation time
Druyer, Rémy. "Réseau sur puce sécurisé pour applications cryptographiques sur FPGA." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTS023/document.
Whether through smartphones, portable game consoles, or high performances computing, Systems-on-Chip (SoC) have seen their use widely spread over the last two decades. This can be explained by the low power consumption of these circuits with the regard of the performances they are able to deliver, and the numerous function they can integrate. Since SoC are improving every day, they require better performances from interconnects that support their communications. In order to address this issue Network-on-Chip have emerged.In addition to ASICs, FPGA circuits are one of the possible choices when conceiving a SoC. Our first contribution was therefore to perform and study the performance of Hermes NoC initially designed for ASIC, on reconfigurable circuit. This allowed us to confirm that the architecture of the interconnection system must be adapted to that of the circuit in order to achieve the best possible performances. Thus, our second contribution was to design TrustNoC, an optimized NoC for FPGA platform, with low latency, high operating frequency, and a moderate quantity of logical resources required for implementation.Security is also a primordial aspect of systems-on-chip, and more generally, of all digital systems. Our latest contribution was to study the threats that target SoCs during all their life cycle, then to develop and integrate hardware security mechanisms to TrustNoC in order to counter IP hijacking, and software attacks. During the design of security mechanisms, we tried to limit as much as possible the overhead on NoC performances
Rosay, Sophie. "A statistical mechanics approach to the modelling and analysis of place-cell activity." Thesis, Paris, Ecole normale supérieure, 2014. http://www.theses.fr/2014ENSU0010/document.
Place cells in the hippocampus are neurons with interesting properties such as the corre-lation between their activity and the animal’s position in space. It is believed that theseproperties can be for the most part understood by collective behaviours of models of inter-acting simplified neurons. Statistical mechanics provides tools permitting to study thesecollective behaviours, both analytically and numerically.Here, we address how these tools can be used to understand place-cell activity withinthe attractor neural network paradigm, a theory for memory. We first propose a modelfor place cells in which the formation of a localized bump of activity is accounted for byattractor dynamics. Several aspects of the collective properties of this model are studied.Thanks to the simplicity of the model, they can be understood in great detail. The phasediagram of the model is computed and discussed in relation with previous works on at-tractor neural networks. The dynamical evolution of the system displays particularly richpatterns. The second part of this thesis deals with decoding place-cell activity, and theimplications of the attractor hypothesis on this problem. We compare several decodingmethods and their results on the processing of experimental recordings of place cells in afreely behaving rat
Trinh, Duy Chi. "Propriétés du réseau de gènes contrôlant l'organisation du primordium de racine latérale chez Arabidopsis thaliana." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG003/document.
Post-embryonic lateral root organogenesis plays an essential role in defining plant root system architecture, and therefore plant growth and fitness. The aim of the thesis is to elucidate the gene regulatory network regulating lateral root development and de novo root meristem formation during root branching in the model plant Arabidopsis thaliana by combining a system-biology based analysis of lateral root primordium transcritome dynamics with the functional characterization of genes possibly involved in regulating lateral root organogenesis.The first part of the thesis deals with the identification the target genes of PUCHI, an AP2/EREBP transcription factor that is involved in controlling cell proliferation and differentiation during lateral root formation. We showed that loss of PUCHI function leads to defects lateral root initiation and primordium growth and organisation. We found that several genes coding for proteins of the very long chain fatty acid (VLCFA) biosynthesis machinery are transiently induced in a PUCHI-dependent manner during lateral root development. Moreover, a mutant perturbed in VLCFA biosynthesis (kcs1-5) displays similar lateral root development defects as does puchi-1. In addition, puchi-1 loss of function mutant roots show enhanced and continuous callus formation in auxin-rich callus induction medium, consistent with the recently reported role of VLCFAs in organizing separated callus proliferation on this inductive growing medium. Thus, our results show that PUCHI positively regulates the expression of VLCFA biosynthesis genes during lateral root development, and further support the hypothesis that lateral root and callus formation share common genetic regulatory mechanisms.A second part of the thesis specifically addresses the issue of identifying key regulators of root meristem organization in the developing lateral root primordium. Material enabling the tracking of meristem cell identity establishment in developing primordia with live confocal microscopy was generated. A gene network inference was run to predict potential regulatory relationships between genes of interest during the time course of lateral root development. It identified potential regulators of quiescent center formation, a key step in functional organization of the lateral root primordia into a new root apical meristem. The characterization of some of these candidate genes was initiated.Altogether, this work participated in deciphering the genetic regulation of lateral root formation in Arabidopsis thaliana
Pécot, Jessie. "Dépendance des cellules cancéreuses à BCL-xL : ciblage thérapeutique du réseau d'interactions PUMA, BAX et BCL-xL : effets oncogéniques non canoniques de l'interaction RAS / BCL-xL." Nantes, 2015. https://archive.bu.univ-nantes.fr/pollux/show/show?id=57dfe09c-18e6-4d60-a1e1-cbc567f5cda6.
BCL-xL plays a role in chemoresistance that needs to be overcome. We show here that currently available BH3-mimetics do not efficiently derepress BCL-xL inhibition of BAX-mediated cell death induced by PUMA, a major pro-apoptotic effector of chemotherapy. Live cell measurements of protein-protein interactions reveal that BH3-mimetics readily inhibit BAX interactions with BCL-xL and the effects of BCL-xL on BAX oligomerization but that PUMA interactions with BCL-xL are highly resistant. Thus, PUMA only favors BAX oligomerization/activation and induction of cell death in response to BH3-mimetics when BCL-xL expression is limiting. Mutagenesis studies show that the robustness of PUMA/BCL-xL interactions is due to the avidity of the PUMA BH3 domain for mitochondrial BCL-xL. This has important consequences for the design of strategies combining PUMA-inducing genotoxics and BCL-xL inhibitors, and argues that mitochondrial membranes per se influence treatment outcome. BCL-xL does not only function as guardian of mitochondrial permeability. Non-canonical effects and functions of this protein have been described, as its interaction with the RAS oncogene. Some studies suggest the oncogenic effects of the BCL-xL/RAS interaction. However, its functional consequences remain unknown. So we have used BRET and pep-scan assays in order to structurally and functionally characterize this interaction
Fauré, Adrien. "Modélisation logique du réseau de régulation contrôlant le cycle cellulaire chez les eucaryotes." Aix-Marseille 2, 2009. http://theses.univ-amu.fr.lama.univ-amu.fr/2009AIX22066.pdf.
Deregulation of the cell cycle can lead to important damage to the cell itself, or to the whole organism. Indeed, unrestricted proliferation is one of the hallmarks of cancer. Moreover, cell cycle control is very flexible, allowing the cell to adapt to many different external and internal signals. Response to these signals may involve profound modifications, including cell cycle arrest, or yet the possibility to “skip” one phase of the canonical cycle, as in endocycles, syncytial cycles or meiosis. In regard to the scarcity of quantitative data, we chose the logical formalism to study the cell cycle from a theoretical point of view. Moreover, the relative simplicity of this formalism allows us to rapidly build large models involving tens of components. Last but not least, this formalism comes with specific analytical tools, including the possibility to identify stable states and analyse the dynamical role of specific regulatory circuits. After an introduction to both the cell cycle and the logical formalism, I present the results obtained during my Ph. D, articulated around the articles I co-authored. The first part of my work deals with a schematic logical model of the mammalian cell cycle and the prioritisation system developed in this context. The second part deals with budding yeast and a modular approach used to extend and update a model of the core cell cycle engine with regulatory modules developed separately. Finally, the third part presents my contribution to the latest public version of the logical modelling software GINsim. In the discussion, I analyse the conservation of functional regulatory circuits in various logical models of the cell cycle in different organisms. Next I discuss perspectives of extension of the budding yeast and mammalian models open by the modular approach. Finally I consider the questions raised by my work in terms of modularity, circuit functionality and robustness
Krammer, Thibault. "Développement d'un réseau microvasculaire sur puce microfluidique pour la reconstruction tissulaire." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAV044.
Tissue engineering aims to develop functional tissues or organs in vitro in order to provide drug testing platforms or transplantable tissues and improve the treatments provided to patients. However, the physiological tissue structures developed to date do not integrate and perfusable vascular network. In vivo, the vascular network supplies the body’s cells with oxygen and nutrients and removes cellular waste and carbon dioxide. It also has a major role in maintaining organ homeostasis. Blood capillaries are hollow vessels whose walls are only composed of a layer of endothelial cells and diffuse nutrients. The blood capillary network is dense and perfuse all tissues. Due to the limit oxygen diffusion inside tissues, each cell is located at most 200µm away from a capillary. The difficulties of building a network of perfusable capillaries and integrating them into tissue constructs limit the development of thick physiological tissues.An innovative technique for developing a microvascular network within a thick construction is presented in this thesis. This technique consists of assembling spherical tissue micro-units within a microfluidic chamber, and developing a network of capillaries through the interstitial pores formed by the spheres packing. Tissue micro-units are composed of biopolymers representative of the extracellular matrix and contain cells from the tissue of interest. A layer of endothelial cells is developed on the surface of these microspheres. The stacking of these microspheres creates a porous medium in which nutrient medium is perfused. Flow control within such a structure allows the application of physical stimuli influencing the self-assembly of endothelial cells into capillaries within the interstitial space of the sphere packing.During this thesis, a device for manufacturing microspheres from natural biopolymers was developed. The structure formed by the stacks of spheres was studied and the flow within such environments were characterized so as to apply controlled physical stimuli to cells. A bioreactor-like perfusion system has been built. A thick tissue structure could be formed within this system and the development of the vascular network was promoted. The formation of the network was demonstrated by the presence of infused blood capillaries within the structure. The technique developed promises to be applied to the development of many tissues and applications for organ-on-chip or tissue engineering devices
Medina, Emmanuelle. "Identification du réseau moléculaire associé à la protéine CRUMBS : Implication pour sa fonction dans la morphogenèse des cellules épithéliales chez la drosophile." Aix-Marseille 2, 2003. http://www.theses.fr/2003AIX22018.
Coulouarn, Cédric. "Développement d'un réseau d'ADNc dédié à l'analyse du transcriptome hépatique humain : application à l'étude de la réponse du foie au cours d'évènements physiologiques et pathologiques." Rouen, 2004. http://www.theses.fr/2004ROUES002.
We have aimed at an extensive coverage of the liver transcriptome and we developed a dedicated Liverpool array of 10000 non-repondant cDNA probes and a LiverTools database. Inflammation-induced transcriptome changes were first studied in vivo. We identified a wealth of genes whose hepatic expression statistically correlates with the extent of inflammation. Some of the cognate proteins are secreted and may provide novel markers of clinical relevance. Next, time-course analysis of the hepatic transcriptome were performed in cytokine-challenged hepatoma cells. Transcriptional gene activity, mRNA stability and translational state, were also studied in vitro and allowed us to determine the respective contributions of these regulatory mechanisms. Another study dealt with a genome-wide comparison of gene regulation in hepatocellular carcinoma (HCC) and fetal liver (FL). Altered gene expression in HCC and FL mostly resulted in down-regulated mRNAs coding for a limited number of functions
Mayorquim, Jorge Luiz. "Étude en vue de la réalisation d'un réseau de neurones binaires logiques : détection de contours en temps réel." Compiègne, 1996. http://www.theses.fr/1996COMPD893.
Polentes, Jérôme. "Plasticité post-lésionnelle des réseaux neurovégétatifs centraux : cas du réseau respiratoire. Récupération fonctionnelle après lésion médullaire et transplantation de cellules gliales gainantes olfactives." Aix-Marseille 3, 2005. http://www.theses.fr/2005AIX30026.
This doctoral work studied, after cervical hemisection in the adult rat, the incidence of a post-traumatic strategy of cell transplantation (Olfactory Ensheathing Cells; CGO) on post-lesional plasticity of a central neurovegetative network (the respiratory network) and on its functional recovery. Three to 6 months post-trauma (or post-lesion), a substantial functional recovery of the ipsilateral phrenic and diaphragmatic activity (mean 80% and 73% of the contralateral activity; Sham group: mean 29% and 10%) is obtained in the Transplanted animals. 57% of the phrenic activity in these animals persisted after suppression of any contralateral pathways. No similar ipsilateral activity could be evidenced in the Sham group. In addition, occurrence of Ipsilateral post-synaptic phrenic response to supralesional stimulations, among the Transplanted group only, reveals the presence of a phrenic reinnervation due to the transplantation strategy
Heil, Mikael. "Conception architecturale pour la tolérance aux fautes d'un système auto-organisé multi-noeuds en réseau à base de NoC reconfigurables." Electronic Thesis or Diss., Université de Lorraine, 2015. http://www.theses.fr/2015LORR0351.
The need of growing performance and reliability of embedded System-on-Chips SoCs are increasing constantly to meet the requirements of applications becoming more and more complexes, new architectural processing paradigms and communication structures based in particular on self-adaptive and self-organizing structures have emerged. These new computing systems integrate within a single chip of hundreds of computing or processing elements (Multiprocessor Systems on Chip - MPSoC) allowing to feature a high level of parallel processing while providing high flexibility or adaptability. The goal is to change possible configurations of the distributed processing characterizing the evolving context of the networked systems. Nowadays, the performance of these systems relies on autonomous and intelligence allowing to deploy and redeploy the compute modules in real time to the request processing and computing power, the communication medium and data exchange between interconnected processing elements to provide bandwidth scalability and high efficiency for the potential parallelism of the available computing power of MPSoC. Moreover, the emergence of the partial reconfigurable FPGA technology allows to the MPSoC to adapt their elements during its operation in order to meet the system requirements. In this context, flexibility, computing power and high bandwidth requirements lead new approach to the design of self-organized and self-adaptive communication systems based Network-on-Chips (NoC). The aim is to allow the interconnection of a large number of elements in the same device while maintaining fault tolerance requirement and a compromise between parallel processing capacity of the MPSoC, communication performance, interconnection resources and tradeoff between performance and logical resources. This thesis work aims to provide innovative architectural solutions for networked fault tolerant MPSoC based on FPGA technology and configured as a distributed and self-organized structure. The objective is to obtain performance and reliable systems on chips incorporating detection, localization and correction of errors in their reconfigurable or adaptive NoC structures where the main difficulty lies in the identification and distinction between real errors and adaptive properties in these network nodes. More precisely, this work consists to perform a networked node based on reconfigurable FPGA which integrates dynamic or adaptive NoC capable of self-organized and self-test in order to achieve maximum maintainability of system operation in a networked environment (WSN). In this work, we developed a reconfigurable multi-node system based on MPSoC which can exchange and interact, allowing an efficient task management and self-management of fault tolerance mechanisms. Different techniques are combined and used to identify and precisely locate faulty elements of such a structure in order to correct or isolate them in order to prevent failures of the system. Validations through the many hardware simulations to estimate their capacity of detecting and locating sources of error within a network have been presented. Likewise, synthesized logic systems incorporating the various proposed solutions are analyzed in terms of performance and logic resources in the case of FPGA technology
León, Huamán Kelly Blanca. "Réseau de contrôle de la traduction par l'Hormone Folliculo-Stimulante." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR4047.
FSH is a key hormone of the reproductive function. A clear understanding of its molecular mechanism is essential to fully understand its biological effects. Here, we show for the first time that FSH not only enhances the assembly of polysomes but also stimulates the translation of at least two mRNA selectively, c-fos and vegfa, in Sertoli cells. p70S6K participates in this mechanism. FSH activates and enhaced p70S6K recruitment to the m7GTP cap structure of mRNA where this kinase phosphorylates its targets. β-arrestins, which are scaffolding proteins that regulate FSH signalling, seem to participate in p70S6K activation. Accordingly, β-arrestins depletion increased p70S6K recruitment to the cap and reduced its enzymatic activity. Importantly, p70S6K and β-arrestins interact but the interaction is not FSH-dependent. We assume that β-arrestins sequester inactive p70S6K to activate it locally and then p70S6K translocates to the cap in response to FSH. In conclusion, this work brings new knowledge about FSH function in translational control and the signaling mechanisms involved
Costa, Luis. "Gestion de cellules des systèmes électriques intégrant des sources de production stochastiques." Phd thesis, École Nationale Supérieure des Mines de Paris, 2008. http://tel.archives-ouvertes.fr/tel-00409587.
Amiot, Franck. "Vers une architecture parallèle reconfigurable dédiée au traitement d'image et à la vision." Rouen, 2000. http://www.theses.fr/2000ROUES077.
Dibao-Dina, Alfred. "Élaboration d’un système in vitro de suivi en continu par spectroscopie d’impédance électrique de l’infection d’une lignée de cellules cancéreuses par un protozoaire parasite : Cryptosporidium parvum." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10002/document.
Cryptosporidium is the main origin of worldwide waterborne epidemic outbreaks caused by protozoan parasites. In this thesis, we show that an in vitro electrical impedance-based device is able to get insights on Cryptosporidium life cycle on a cell culture and to quantify sample infectivity. HCT-8 cells (human adenocarcinoma) were grown to confluency on interdigitated microelectrode arrays during 76 hours and then infected by Cryptosporidium parvum during 60 hours. The impedimetric response was measured at frequencies ranging from 100Hz to 1MHz and a 7min sampling period. As the infection progresses, the impedance signal shows a reproducible distinct succession of peaks at 12, 23 and 31h post infection (PI), and minima at 9, 19 and 28h PI. An electrical equivalent circuit modeling-based approach indicates that these features can be partly explained by the effects of host-parasite interactions on intercellular areas. Furthermore, our data present for the first time a real-time monitoring of early homogeneous parasitic stage development with alternating invasive (i.e. zoites) and proliferative (i.e. meronts) form predominances, observed respectively at peaks and minima in the impedimetric signal. Finally, by quantifying the magnitude of the impedimetric response, we demonstrate this device can also be used as an infectivity sensor as early as 12h PI, thus being at least 4 times faster than other state of the art techniques
Chappet, de Vangel Benoît. "Modèles cellulaires de champs neuronaux dynamiques." Electronic Thesis or Diss., Université de Lorraine, 2016. http://www.theses.fr/2016LORR0194.
In the constant search for design going beyond the limits of the von Neumann architecture, non conventional computing offers various solutions like neuromorphic engineering and cellular computing. Like von Neumann who roughly reproduced brain structures to design computers architecture, neuromorphic engineering takes its inspiration directly from neurons and synapses using analog substratum. Cellular computing influence comes from natural substratum (chemistry, physic or biology) imposing locality of interactions from which organisation and computation emerge. Research on neural mechanisms was able to demonstrate several emergent properties of the neurons and synapses. One of them is the attractor dynamics described in different frameworks by Amari with the dynamic neural fields (DNF) and Amit and Zhang with the continuous attractor neural networks. These neural fields have various computing properties and are particularly relevant for spatial representations and early stages of visual cortex processing. They were used, for instance, in autonomous robotics, classification and clusterization. Similarly to many neuronal computing models, they are robust to noise and faults and thus are good candidates for noisy hardware computation models which would enable to keep up or surpass the Moore law. Indeed, transistor area reductions is leading to more and more noise and the relaxation of the approx. 0% fault during production and operation of integrated circuits would lead to tremendous savings. Furthermore, progress towards many-cores circuits with more and more cores leads to difficulties due to the centralised computation mode of usual parallel algorithms and their communication bottleneck. Cellular computing is the natural answer to these problems. Based on these different arguments, the goal of this thesis is to enable rich computations and applications of dynamic neural fields on hardware substratum with neuro-cellular models enabling a true locality, decentralization and scalability of the computations. This work is an attempt to go beyond von Neumann architectures by using cellular and neuronal computing principles. However, we will stay in the digital framework by exploring performances of proposed architectures on FPGA. Analog hardware like VLSI would also be very interesting but is not studied here. The main contributions of this work are : 1) Neuromorphic DNF computation ; 2) Local DNF computations with randomly spiking dynamic neural fields (RSDNF model) ; 3) Local and asynchronous DNF computations with cellular arrays of stochastic asynchronous spiking DNFs (CASAS-DNF model)
Grieco, Luca. "Modélisation et analyse des dérégulations tumorales du réseau MAPK chez l'homme." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4011.
MAPK network consists of tightly interconnected signalling pathways. Although several studies established the involvement of this network in cancer deregulations, the precise mechanisms underlying its influence on the balance between cell proliferation and death remain elusive.Public data were integrated into a detailed reaction map, accounting for the influence of MAPK network on cell fate decision. This map was then used for computational analyses addressing specific cancer-related questions.First, the dynamics of MAPK network in bladder cancers were analysed. A Boolean model was built, accounting for the response of the network to selected inputs. The results of systematic simulations were found globally coherent with published data. Based on in silico experiments, the main events underlying different observed cancer cell behaviours were then deciphered.Next, the MAPK reaction map was exploited to reanalyse public high-throughput gene expression data. The goal was to identify key actors for the transduction of proliferative signals, in specific cell types. Network analyses and statistical computations led to the identification of deregulated MAPK network regions, and to the delineation of optimal intervention points aimed at blocking the proliferative signals transduced from such regions. This approach was used to study five different tumour stages and four different subtypes of T-cell lymphoma.Altogether, these results led to the formulation of novel hypotheses concerning the functioning of MAPK network in different pathological conditions, and to the selection of target components that might be considered for the development of novel treatments
Cenier, Tristan. "Interactions entre rythmes rapides et rythmes lents dans la représentation de l’information olfactive dans le réseau bulbaire." Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10093/document.
A striking feature of the olfactory sensory system is its ability to deal with a complex multi-dimensional chemical stimuli. Receptor cells in the nasal cavity are sensitive to specific features of molecules and transmit this information to the olfactory bulb, first relay for olfaction in the central nervous system. Due to the organization of projection pathways to the bulb, afferent information activates the structure in a topographical fashion ; although this may constitute a coding strategy for olfactory information it has proven insufficient, and other strategies must be investigated. Dynamic phenomenons are a preponderant feature of the olfactory bulb. The respiratory rhythm imposes a sinusoidal level of activation to the system, oscillations in local field potentials and subthreshold oscillations in neurons membrane potentials may interact and lead to the transient synchronization of sub-populations of neurons. This particular mechanism, designated as neural assemblies, is in theory a good candidate for the representation of olfactory information. The work presented here is based on conjoint recordings, in anesthetized animals, of unitary activities, oscillations in the LFP and respiration, in response to olfactory stimulation. We show the relationships existing between the various dynamic phenomenons, and hypothesize on their functional roles. We propose that a same mechanism may form different neural assemblies each assuming a specific functional role. The respiratory rhythm acts as a gating system, organizing the formation of successive yet different neural assemblies
Decalf, Jérémie. "Les cellules dendritiques plasmacytoïdes au cours de l'infection chronique par le virus de l'hépatite C : de l'immunologie fondamentale à l'application dans le développement de nouvelles thérapies." Paris 6, 2008. http://www.theses.fr/2008PA066030.