Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-21T16:58:53Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_SilviaVersaoFinal.pdf: 3562807 bytes, checksum: d273ad6c061161f899cab3d232a82a79 (MD5) / Made available in DSpace on 2017-02-21T16:58:54Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_SilviaVersaoFinal.pdf: 3562807 bytes, checksum: d273ad6c061161f899cab3d232a82a79 (MD5) Previous issue date: 2016-08-01 / FACEPE / Contexto: A fase de especificação de requisitos é fundamental no processo de desenvolvimento de software. O uso de cenários é bastante popular para especificar requisitos, por serem descritos em linguagem natural. No entanto, a linguagem natural dá margem a requisitos ambíguos, incompletos e inconsistentes, o que vai de encontro com os objetivos da fase de especificação de requisitos. Nesse sentido, uma técnica baseada em Cenário & LEL (Language Extended Lexicon), chamada de C&L, pode ser a solução adequada, pois LEL é um glossário que define um conjunto de palavras que pertencem a um domínio e que devem ser usadas para descrever os cenários. Assim, C&L é considerada uma técnica de cenários baseada em linguagem natural controlada que ajuda a minimizar os problemas previamente mencionados, além de poder ser utilizada para criar casos de teste de forma mais sistemática. Objetivo: Neste trabalho, são propostas duas abordagens: a primeira abordagem usa regras de mapeamento para derivar modelos statechart a partir de C&L visando verificar a completude e consistência desses cenários e a segunda usa heurísticas para obter sistematicamente casos de teste a partir de modelos statechart. Método: A pesquisa apresentada nessa dissertação seguiu a abordagem de Engenharia para definir as regras de mapeamento e as heurísticas que, por sua vez, foram avaliadas empiricamente. Resultados: As regras de mapeamento apoiam a derivação de statechart a partir de C&L. As heurísticas apoiam a derivação de casos de teste a partir dos modelos statechart. Foi realizado um experimento para comparar o número de erros de incompletude e inconsistência detectados pelos grupos experimental e controle e o tempo gasto pelos grupos para detectar esses erros. Também foi verificado se os statecharts gerados através da aplicação das regras de mapeamento possuem grau de corretude e semelhança. Foi realizada uma avaliação qualitativa das heurísticas utilizadas para derivar os casos de teste, com o intuito de saber se as heurísticas foram utilizadas corretamente, se estão claras e são fáceis de usar. Conclusões: Os resultados do experimento mostram que o número de erros de incompletude detectados pelo grupo experimental foi superior ao número obtido pelo grupo controle e em relação aos erros de inconsistência não houve diferença entre quantidade de erros detectados pelos dois grupos. Além disso, a média do tempo gasto para identificar erros de incompletude e inconsistência pelo grupo experimental foi ligeiramente superior a média do tempo gasto pelo grupo controle. Em relação ao grau de corretude, dentre os modelos gerados pelo grupo experimental, existe um que apresenta o maior grau de corretude com 85,7%. No entanto, o grau de semelhança entre os modelos é considerado de “baixa semelhança”. O resultado da avaliação qualitativa mostrou que os participantes concordaram que as regras de mapeamento e as heurísticas são compreensíveis e fáceis de utilizar. Também foi observado que as heurísticas foram usadas de maneira correta na derivação dos casos de teste. / Context: The requirements specification phase is fundamental in the software development process. The use of scenarios is quite popular to specify requirements because they are described in natural language. However, natural language gives rise to ambiguous, incomplete and inconsistent requirements, jeopardizes the objectives of the requirements specification phase. In this context, a technique based on Scenarios and LEL (Language Extended Lexicon), called C&L, may be an appropriate solution because LEL is a glossary that defines a set of words that belong to a domain and should be used to describe the scenarios. Thus, C&L is a scenario technique based on controlled natural language that helps to minimize the problems previously mentioned, and can be used to create test cases in a more systematic way. Objective: In this study, two approaches are proposed: the first approach uses mapping rules to derive statechart models from C & L in order to verify the completeness and consistency of these scenarios and the second uses heuristics to systematically derive test cases from statechart models. Method: The research presented in this work follows the engineering approach to define the mapping rules and heuristics that, in turn, were empirically evaluated. Results: Mapping rules support the derivation of statechart from C & L. Heuristics support the derivation of test cases from statechart models. An experiment was conducted to compare the number of incompleteness and inconsistency errors detected by the experimental and control the groups and the time spent by groups to detect these errors. Also it was verified whether the statecharts generated by the application of the mapping rules have degree of correctness and likeness. A qualitative evaluation of the heuristics used to derive the test cases was made, in order to know whether the heuristics were correctly used and if they are clear and easy to use. Conclusions: The results of the experiment show that the number of incompleteness errors detected by the experimental group was higher than the number obtained by the control group, and in relation to inconsistency errors, there was no difference among the number of errors detected by the two groups. Furthermore, the average time spent to identify incompleteness and inconsistency errors by the experimental group was slightly higher than the average time spent by the control group. In relation to the degree of correctness among the models generated by the experimental group, there is one that has the highest degree of correctness with 85.7%. However, the degree of similarity between the models is considered "low similarity”. The result of the qualitative evaluation showed that the participants agreed that the mapping rules and heuristics are comprehensible and easy to use. It was also observed that the heuristics were used correctly in the derivation of test cases.

Orientador: Walter da Cunha Borelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-07-23T08:02:09Z (GMT). No. of bitstreams: 1 Macario_CarlaGeovanadoNascimento_M.pdf: 8704471 bytes, checksum: bee9de6493b42d0139961cb43f32cb24 (MD5) Previous issue date: 1997 / Resumo: Este trabalho propõe uma metodologia alternativa para o desenvolvimento e evolução do AIOA, um software para o gerenciamento e análise de dados experimentais, em desenvolvimento na Embrapa. Esta nova metodologia consiste no uso combinado da técnica OMT (Object Modeling Technique) com a linguagem de especificação formal SOL (Specification and Oescription Language), e apresenta facilidades que produzem ga¿n ANTPOT. H¿os no processo de desenvolvimento de software, como a possibilidade de validação e de simulação do sistema, e também a geração de código para sua prototipação. A partir do modelo de classes proposto pela OMT, passa-se à especificação do sistema em SOL, levando-se em conta na elaboração de ambos os modelos, conceitos como reuso, herança e evolução de sistemas. A validação, a simulação e a geração de código do sistema tornam-se possíveis com o uso da ferramenta CASE SOT1(SOL Oesign Tool - Telelogic, Suécia). É apresentada a evolução do ambiente AIOA centralizado até uma versão distribuída, considerando uma arquitetura cliente-servidor com mecanismo CORBA, bem como exemplos de simulação e de validação destes sistemas / Abstract: The present work proposes an alternative methodology for the development and evolution of AIOA, a software environment for the management and analysis of experimental data, being developed at Embrapa, Brazil. This new technique consists of the combined use of OMT (Object Modeling Technique) with the formal specification language SDL (Specification and Description Language), in its 1992 version SDL-92, presenting strong facilities on the software development process, allowing the validation, simulation and eventual code generation for software prototyping. From the system object model and after mapping to SOL-92, the formal specification is generated considering concepts such as reuse, inheritance, and system evolution. The validation, the simulation and code generation of the system is allowed through the use of the CASE tool SOT (SOL Oesign Tool - Telelogic, Sweden). The specification of the centralized AIOA to its evolution to distributed version are presented, validated and simulated. This is followed up with a specialization and validation of thedistributed AIOA, considering an arquitecture client-server with CORBA mechanism / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Made available in DSpace on 2014-07-29T14:57:52Z (GMT). No. of bitstreams: 1 Diss LuNishi.pdf: 535052 bytes, checksum: 312e4f56b2249ade58df12ebfe2b4dcb (MD5) Previous issue date: 2009-09-16 / This work uses mind maps to describe requirements and investigates this not well known application through an experiment. The experiment was based on desirable features sought by requirements engineers in notations and functions offered by tools. Both provided input to small changes in mind maps before a real specification was produced for the experiment. The results show that mind maps should be considered seriously as an alternative notation to describe software requirements / Este trabalho investiga o uso de mapas mentais na engenharia de requisitos, com destaque para o registro de requisitos. Características e funcionalidades desejáveis por engenheiros de requisitos foram coletadas e motivaram adaptações nos mapas mentais para uso neste domínio. Um experimento empregou a notação alterada e forneceu indícios positivos e negativos. O experimento permite, contudo, considerar o uso de mapas mentais como uma alternativa viável para o registro de requisitos e merecedora de pesquisas posteriores

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-04-11T19:28:47Z No. of bitstreams: 2 Dissertação - Nayara de Souza Silva - 2017.pdf: 2066646 bytes, checksum: 95e09b89bf69fe61277b09ce9f1812a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-12T14:32:03Z (GMT) No. of bitstreams: 2 Dissertação - Nayara de Souza Silva - 2017.pdf: 2066646 bytes, checksum: 95e09b89bf69fe61277b09ce9f1812a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-12T14:32:03Z (GMT). No. of bitstreams: 2 Dissertação - Nayara de Souza Silva - 2017.pdf: 2066646 bytes, checksum: 95e09b89bf69fe61277b09ce9f1812a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-07 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The process of developing computer systems takes into account many stages, in which some are more necessary than others, depending on the purpose of the application. The implementation stage is always necessary, indisputably. Sometimes the requirements analysis and testing phases are neglected. And, generally, the part of formal verification correctness is intended for few applications. The use of model checkers has been exploited in the task of validating a behavioral specification in its appropriate level of abstraction, notably specifications validation of critical systems, especially when they involve the preservation of human life, when the existence of errors entails huge financial loss or when deals with information security. Therefore, it proposes to apply formal verification techniques in the validation of the vehicular safety system Avoiding Doored System, considered as critical, in order to verify if the implemented system faithfully meets the requirements for it proposed. For that, it was used as a tool to verify its correctness the Specification and Verification System - PVS, detailing and documenting all the steps employed in the process of specification and formal verification. K / O processo de desenvolvimento de sistemas computacionais leva em conta muitas etapas, nos quais umas são tidas mais necessárias que outras, dependendo da finalidade da aplica- ção. A etapa de implementação sempre é necessária, indiscutivelmente. Por vezes as fases de análise de requisitos e de testes são negligenciadas. E, geralmente, a parte de verifica- ção formal de corretude é destinada a poucas aplicações. O uso de verificadores de modelos tem sido explorado na tarefa de validar uma especificação comportamental no seu nível adequado de abstração, sobretudo, na validação de especificações de sistemas críticos, principalmente quando estes envolvem a preservação da vida humana, quando a existência de erros acarreta enorme prejuízo financeiro ou quando tratam com a segurança da informa- ção. Diante disso, se propõe aplicar técnicas de verificação formal na validação do sistema de segurança veicular Avoiding Doored System, tido como crítico, com o intuito de atestar se o sistema implementado atende, fielmente, os requisitos para ele propostos. Para tal, foi utilizada como ferramenta para a verificação de sua corretude o Specification and Verification System - PVS, detalhando e documentando todas as etapas empregadas no processo de especificação e verificação formal. Pal

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-13T15:34:18Z No. of bitstreams: 1 Dissertação - Mitsuyoshi N. Carvalho.pdf: 2218487 bytes, checksum: dee728ee846d66a58515c2e64c63ff4f (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-13T15:35:18Z (GMT) No. of bitstreams: 1 Dissertação - Mitsuyoshi N. Carvalho.pdf: 2218487 bytes, checksum: dee728ee846d66a58515c2e64c63ff4f (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-13T15:35:51Z (GMT) No. of bitstreams: 1 Dissertação - Mitsuyoshi N. Carvalho.pdf: 2218487 bytes, checksum: dee728ee846d66a58515c2e64c63ff4f (MD5) / Made available in DSpace on 2016-12-13T15:35:51Z (GMT). No. of bitstreams: 1 Dissertação - Mitsuyoshi N. Carvalho.pdf: 2218487 bytes, checksum: dee728ee846d66a58515c2e64c63ff4f (MD5) Previous issue date: 2013-02-28 / FINEP - Financiadora de Estudos e Projetos / The Common Channel Signaling System No. 7 (SS7) is one of the most important signaling systems used in today’s telecommunication networks and continues to be used on new architectures of fixed and mobile telephony. This dissertation presents an implementation for the control functions of the Signaling System Number 7 level 2 (referred in this work as MTP2-H) using the VHDL as the hardware description language. The specification of the control functions for the SS7 level 2 is made by using SDL diagrams described in Recommendation Q.703 of ITU-T. To accomplish the implementation, a methodology was developed for conversion of systems described in SDL to VHDL, consisting of a set of rules and a standard VHDL model that were applied on those SDL diagrams. The implementation was performed in order to provide the modularity and portability characteristics to the generated code. This way, the developed module can be replicated as many times as necessary in a programmable logic component (respecting the limitations of the component) and can also be synthesized in components from different manufacturers. The validation of implementation was done by means of functional tests using the Modelsim simulation tool. The developed code was compiled in development tools from different manufacturers to validate the portability feature and to estimate the amount of resources required in programmable logic components. / O Sistema de Sinalização por Canal Comum número 7 (SS7) é um dos mais importantes sistemas de sinalização utilizado em redes atuais de telecomunicações e continua a ser usado em novas arquiteturas tanto de telefonia fixa como móvel. O presente trabalho de dissertação apresenta a implementação das funções de controle do nível 2 do Sistema de Sinalização número 7 (denominado nesse trabalho como MTP2-H) utilizando a linguagem de descrição de hardware VHDL. A especificação das funções de controle do nível 2 do SS7 é feita através de diagramas em linguagem SDL na recomendação Q.703 do ITU-T. Para realizar a implementação, foi desenvolvida uma metodologia para conversão de sistemas descritos em SDL para VHDL, composta por um conjunto de regras e um modelo padrão em VHDL que foram aplicados nos referidos diagramas SDL. A implementação foi realizada de forma a proporcionar características de modularidade e portabilidade ao código gerado. Com isso, o módulo desenvolvido poderá ser replicado o número de vezes em que for necessário em um componente de lógica programável (respeitando as limitações do componente) e também poderá ser sintetizado em componentes de diferentes fabricantes. A validação da implementação foi feita por meio de testes funcionais utilizando a ferramenta de simulação Modelsim. O código desenvolvido foi compilado em ferramentas de desenvolvimento de diferentes fabricantes para validar a característica de portabilidade e para estimar a quantidade de recursos necessários nos componentes de lógica programáveis.

Orientador: Walter da Cunha Borelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T00:34:51Z (GMT). No. of bitstreams: 1 Castro_MarcelCavalcantide_M.pdf: 1488533 bytes, checksum: 5a2e57ba0fe96d5603c60ef84835b558 (MD5) Previous issue date: 2004 / Resumo: Este trabalho apresenta propostas de implementação de qualidade de serviço na arquitetura VPN MPLS e analise de desempenho destas propostas. São desenvolvidos sistemas com base na arquitetura VPN MPLS e sugerido uma proposta de expansão da arquitetura VPN MPLS para mapeamento dinamico das prioridades dos clientes VPN na rede do provedor de serviço atraves da inserção do valor de prioridade de rota na tabela vrf e modificações realizadas no protocolo MP-BGP. As propostas foram especificadas utilizando a linguagem de especificação formal SDL orientada a objetos a partir da ferramenta SDL TAU Suite. Esta ferramenta permite simular os sistemas especificados, a partir de diagramas MSC, e validar estes sistemas para detecção e correção dos erros de logica e de especificação. A analise de desempenho das propostas foi realizada com o uso do simulador Opnet Modeler / Abstract: This work describe proposals for the implementation of quality of service (QoS) in VPN MPLS architecture, and their performance analysis based on simulations are presented. New systems are developed based on the VPN MPLS architecture, and it is being proposed an extension for the VPN MPLS architecture to construct a dynamic mapping of VPN clients priorities into service provider network through the insertion of priority field at vrf table and MP-BGP protocol modification. All these systems were specified using the SDL object-oriented formal language with the SDL TAU Suite tool (Telelogic, Sweden). This tool allows the simulation with MSC diagrams of the specified systems, and the validation of these systems by detecting and correcting logical and specification errors. The performance analysis of these proposals were realized through the Opnet Modeler simulator / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Les indications géographiques et les appellations d’origine sont des signes distinctifs ayant de fortes valeurs économiques, sociales et culturelles. Tout d’abord, ces dénominations constituent une importante source de revenus pour les producteurs ; ensuite, elles constituent une garantie de qualité pour les consommateurs; enfin,elles sont un outil de développement rural du pays d’origine ainsi que de protection de son patrimoine culinaire et culturel. Par conséquent, la protection juridique de ces dénominations est primordiale. À cet effet, le législateur communautaire a prescrit, dans le règlement européen n° 510/2006 relatif à la protection des indications géographiques et des appellations d’origine, les règles de forme et de fond relatives à la reconnaissance et la protection de ces dénominations de la manière la plus détaillée. Au Liban, le ministère de l’Économie et du Commerce a préparé un projet de loi sur la protection des dénominations géographiques largement inspiré du règlement européen. Dans ce contexte, les spécificités agricoles, sociales et économiques du pays devront être prises en considération par le législateur libanais.D’ailleurs, la réputation de cette catégorie de dénominations dépasse en principe les frontières nationales du pays d’origine. C’est ainsi que ces dénominations constituent aujourd’hui un enjeu crucial dans le cadre des négociations commerciales internationales surtout au niveau de l’Accord sur les Droits de la Propriété Intellectuelle qui touchent au Commerce (ADPIC), qui constitue l’accord de référence dans ce domaine. / Geographical indications and designations of origin are distinctive signs with high economic, social and cultural values. Firstly, these names are an important source of income for producers, then they are a quality guarantee for consumers, and finally, they are a tool for rural development of their country of origin and also of protection of its cultural and culinary heritage. Therefore, the legal protection of these names is paramount. To this end, the legislator of the European Union has prescribed, in the European Regulation n° 510/2006 on the protection of geographical indications and designations of origin, formal and substantives rules on the recognition and the protection of these names with ample details. In Lebanon, the Ministry of Economy and Trade has prepared a draft law on the protection of geographical designations largely inspired by the European Regulation. In this context, the agricultural, social and economic characteristics of the country must be taken into account by the Lebanese legislator. Moreover, the reputation of this kind of designations exceeds in principle the national borders of the country of origin. Thus, these designations are now a critical issue in the context of international trade negotiations especially in terms of the agreement on Trade Related Aspects of Intellectual Property Rights (TRIPS) which is the reference in this domain.

Since the first lines of code were introduced in the automotive domain, vehicles have transitioned from being predominantly mechanical systems to software intensive systems. With the ever-increasing computational power and memory of vehicular embedded systems, a set of new, more powerful and more complex software functions are installed into vehicles to realize core functionalities. This trend impacts all phases of the system development including requirements specification, design and architecture of the system, as well as the integration and testing phases. In such settings, creating and managing different artifacts during the system development process by using traditional, human-intensive techniques becomes increasingly difficult. One problem stems from the high number and intricacy of system requirements that combine functional and possibly timing or other types of constraints. Another problem is related to the fact that industrial development relies on models, e.g. developed in Simulink, from which code may be generated, so the correctness of such models needs to be ensured. A potential way to address of the mentioned problems is by applying computer-aided specification, analysis and verification techniques already at the requirements stage, but also further at later development stages. Despite the high degree of automation, exhaustiveness and rigor of formal specification and analysis techniques, their integration with industrial practice remains a challenge. To address this challenge, in this thesis, we develop the foundation of a framework, tailored for industrial adoption, for formal specification and analysis of system requirements specifications and behavioral system models. First, we study the expressiveness of existing pattern-based techniques for creating formal requirements specifications, on a relevant industrial case study. Next, in order to enable practitioners to create formal system specification by using pattern-based techniques, we propose a tool called SeSAMM Specifier. Further, we provide an automated Satisfiability Modulo Theories (SMT)-based consistency analysis approach for the formally encoded system requirements specifications. The proposed SMT-based approach is suitable for early phases of the development for debugging the specifications. For the formal analysis of behavioral models, we provide an approach for statistical model checking of Simulink models by using the UPPAAL SMC tool. To facilitate the adoption of the approach, we provide the SIMPPAAL tool that automates procedure of generating network of stochastic timed automata for a given Simulink model. For validation, we apply our approach on a complex industrial model, namely the Brake-by-Wire function from Volvo GTT. / VeriSpec

Nous proposons à travers ce travail de thèse une analyse théorico-clinique en contexte écologique de la problématique des personnes adultes, sujettes au syndrome de l'autisme avec retard mental profond associé, accompagnées en structure médico-sociale, qui constituent une population spécifique du fait de la sévérité particulière de leur handicap et de la grande difficulté pour autrui à accéder à leur subjectivité. Suivant une double démarche éthique et épistémologique, nous avons élaboré de manière complémentaire une modélisation théorique compréhensive de la cognition de ces sujets, basé sur leur singularité développementale, et une méthode d'investigation de leur vécu et fonctionnement sur plusieurs niveaux, adaptée à la complexité de leur problématique et de leur cadre de vie. Suite à cinq études de cas et l'exemple d'une intervention systémique psycho-éducative, nous présentons une synthèse des facteurs susceptibles de contribuer à la situation de handicap de ces sujets. / We propose through this work of thesis a theoretical and clinical analysis in ecological context of the issue of the adult people, prone to the syndrome of autism with severe mental retardation, cared for within medico-social structures. These subjects constitute a specific population, because of the particular severity of their disabilities and of the great difficulty for others of reaching their subjectivity. According to a double ethical and epistemological approach, we worked out in a complementary way an understanding theoretical modeling of the cognition of these subjects, based on their developmental singularity, and a method of investigation of their experience and functioning, on several levels, adapted to the complexity of their issue and to their living environment. Following five case studies and an example of a psycho-educational systemic intervention, we present a synthesis of the factors likely to contribute to the disability situation of these subjects.

During embryonic development, multipotent cardiovascular progenitor cells (MCPs) are specified from early mesoderm. Although the core cardiac transcriptional machinery acting during cardiac cell differentiation is relatively well known, the molecular mechanism acting upstream of these cardiac transcriptional factors, and promoting cardiac progenitor specification from early mesoderm remains poorly understood. We used embryonic stem cell (ESC) differentiation as a model to dissect the molecular mechanisms implicated in cardiovascular progenitor specification. Using ESCs, in which gene expression can be temporally regulated, we showed that transient expression of Mesp1 dramatically accelerates and enhances multipotent cardiovascular progenitor specification through an intrinsic and cellular autonomous mechanism. Using genome wide transcriptional analysis, we found that Mesp1 rapidly activates and represses a discrete set of genes. Using chromatin immunoprecipitation, we showed that Mesp1 directly binds to regulatory DNA sequences located in the promoter of many key genes belonging to the core cardiac transcriptional machinery, resulting in their rapid upregulation. Mesp1 also directly and strongly represses the expression of key genes regulating other early mesoderm and endoderm cell fates. Using engineered ESC expressing the green fluorescent protein under the control of the Mesp1 promoter, we isolated Mesp1 expressing cells in differentiating ESCs allowing characterization of the cellular and molecular mechanisms underlying cardiovascular specification. Our results demonstrate that Mesp1 acts as a key regulatory switch during cardiovascular specification, residing at the top of the hierarchy of the gene network responsible for cardiovascular cell fate determination. Moreover our results place Mesp1 upstream of the specification of both first and second heart fields and provide novel and important insights into the molecular mechanisms underlying the earliest step of cardiovascular specification. We identified cell surface markers expressed allowing the isolation of early cardiovascular progenitors and provide potentially novel methods for dramatically increasing the number of cardiovascular cells for cellular therapy in humans. / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished