O protocolo International Electrotechnical Commission (IEC)-61850 tornou possível integrar os equipamentos das subestações de energia elétrica, através de uma rede de comunicação de dados Ethernet de alta velocidade. A utilização deste protocolo tem como objetivo principal a interligação dos Intelligent Electronic Devices (IEDs) para a automatização dos processos no sistema elétrico. As contribuições deste protocolo para a integração do controle e supervisão do sistema elétrico são diversas, porém, o fato de utilizar uma rede de comunicação de dados Ethernet integrada expõe o sistema elétrico à ataques cibernéticos. A norma IEC-62351 estabelece uma série de recomendações para prover segurança à rede de comunicação do sistema elétrico, dentre elas, o gerenciamento da rede de comunicação, a análise dos campos da mensagem Generic Object Oriented Substation Event (GOOSE) e a utilização de sistemas de detecção de intrusão. O presente trabalho descreve o desenvolvimento de um Intrusion Detection System (IDS) que atende os requisitos de segurança propostos pelo protocolo IEC-62351, para a identificação de ataques à comunicação realizada por mensagens GOOSE do protocolo IEC-61850, e entre equipamentos do sistema elétrico. Para o desenvolvimento desta aplicação, foram identificados os campos que compõem as mensagens GOOSE, de forma a reconhecer os valores esperados em diferentes situações de operação do sistema elétrico. Determinaram-se padrões de comportamento a serem utilizados para discernir mensagens falsas na rede de comunicação. Instalou-se e configurou-se um sistema operacional de tempo real embarcado na plataforma de desenvolvimento Zynq Board (ZYBO), juntamente com o controlador Open-Mul, para gerenciar a rede de comunicação da subestação, através do protocolo OpenFlow, realizando otimizações para o tráfego multicast. Foi desenvolvido um sistema de detecção e bloqueio de mensagens GOOSE falsas que utiliza o protocolo OpenFlow para controle da rede de comunicação do Sistema Elétrico. Desenvolveu-se ainda um sistema inteligente, utilizando-se uma Rede Neural Artificial (RNA) Nonlinear Autoregressive Model with Exogenous Input (NARX), para predição do tráfego realizado por mensagens GOOSE e detecção de ataques Distributed Deny of Service (DDOS). Os resultados obtidos demonstraram que o protocolo OpenFlow pode ser uma ferramenta interessante para controle da rede, porém, os fabricantes necessitam amadurecer sua implementação nos switches, para que sejam utilizados em produção nas redes de comunicação das subestações. O sistema de predição do tráfego gerado por mensagens GOOSE apresentou benefícios interessantes para a segurança da rede de comunicação, demonstrando potencial para compor um sistema de detecção de ataques DDOS realizado por mensagens GOOSE, na rede de comunicação das subestações de energia elétrica. / The IEC-61850 made it possible to integrate equipments of electric power system substations to a high-speed Ethernet data communication network. Its main goal is the interconnection of IEDs for the automation of processes in an electrical system. The contributions of this protocol for the integration of the control and supervision of the electrical system are diverse, although an Ethernet network exposes the electrical system for cyber attacks. The IEC-62351 states a series of recommendations to provide security to the communication network of the electrical system, such as the communication network management, the analysis of GOOSE messages and the use of intrusion detection systems. This study describes the development of an IDS that meets the security requirements proposed by the IEC-62351 standard to identify attacks on communication between GOOSE messages exchanged by electrical equipment using IEC-61850. For the development of this application, fields of the GOOSE messages were identified, in order to recognize the expected values in different power system operating conditions. Behaviour patterns were determined to detect false messages on the communication network. A real-time embedded operating system on ZYBO was installed and configured, as well as the OpenMul controller to manage the communication network of the substation through the OpenFlow protocol, performing optimizations for multicast traffic. A detection system and block tamper GOOSE messages, using the OpenFlow protocol for control of the electrical system communication network, were developed. In addition, an intelligent system using an Artificial Neural Network (ANN) Nonlinear Autoregressive Model with Exogenous Input (NARX) for predicting of the GOOSE messages traffic and the detection of Distributed Deny of Service attack (DDOS) were also developed. The results obtained show that the OpenFlow protocol may be a valuable tool for network control, however, manufacturers should maturely carry on with its implementation in the switches, so that it be used in substation communication networks. The traffic prediction system of the GOOSE messages presented interesting benefits for the security of the communication network, demonstrating potential to built a DDOS attack detection system performed by GOOSE messages on the communication network of electric power substations.

L'interopérabilité des applications est devenue le leitmotiv des développeurs et concepteurs en ingénierie système. La plupart des approches pour l'interopérabilité existant dans l'entreprise ont pour objectif principal l'ajustement et l'adaptation des types et structures de données nécessaire à la mise en œuvre de collaboration entre entreprises. Dans le domaine des entreprises manufacturières, le produit est une composante centrale. Des travaux scientifiques proposent des solutions pour la prise en compte des systèmes d'information issus des produits, tout au long de leur cycle de vie. Mais ces informations sont souvent non corrélées. La gestion des données de produit (PDM) est couramment mise en œuvre pour gérer toute l'information relative aux produits durant tout leur cycle de vie. Cependant, ces modèles sont généralement des "îlots" indépendants ne tenant pas compte de la problématique d'interopérabilité des applications supportant ces modèles. L'objectif de cette thèse est d'étudier cette problématique d'interopérabilité appliquée aux applications utilisées dans l'entreprise manufacturière et de définir un modèle ontologique de la connaissance des entreprises relatives aux produits qu'elles fabriquent, sur la base de leurs données techniques. Le résultat de ce travail de recherche concerne la formalisation d'une méthodologie d'identification des informations de gestion techniques des produits, sous la forme d'une ontologie, pour l'interopérabilité des applications d'entreprises manufacturières, sur la base des standards existants tels que l'ISO 10303 et l'IEC 62264. / In recent years, the enterprise applications interoperability has become the leitmotiv of developers and designers in systems engineering. Most approaches to interoperability in the company have the primary objective of adjustment and adaptation of types and data structures necessary for the implementation of collaboration between companies. In the field of manufacturing, the product is a central component. Scientific works propose solutions taking into account information systems derived from products technical data throughout their life cycle. But this information is often uncorrelated. The management of product data (PDM) is commonly implemented to manage all information concerning products throughout their life cycle. The modelling of management and manufacturing processes is widely applied to both physical products and services. However, these models are generally independent “islands” ignoring the problem of interoperability between applications that support these models. The objective of this thesis is to study the problem of interoperability applied to applications used in the manufacturing environment and to define a model of the ontological knowledge of enterprises related to the products they manufacture, based on technical data, ensuring the interoperability of enterprise systems. The outcome of this research concerns the formalization of a methodology for identifying a product-centric information system in the form of an ontology, for the interoperability of applications in manufacturing companies, based on existing standard such as ISO 10303 and IEC 62264.

O protocolo International Electrotechnical Commission (IEC)-61850 tornou possível integrar os equipamentos das subestações de energia elétrica, através de uma rede de comunicação de dados Ethernet de alta velocidade. A utilização deste protocolo tem como objetivo principal a interligação dos Intelligent Electronic Devices (IEDs) para a automatização dos processos no sistema elétrico. As contribuições deste protocolo para a integração do controle e supervisão do sistema elétrico são diversas, porém, o fato de utilizar uma rede de comunicação de dados Ethernet integrada expõe o sistema elétrico à ataques cibernéticos. A norma IEC-62351 estabelece uma série de recomendações para prover segurança à rede de comunicação do sistema elétrico, dentre elas, o gerenciamento da rede de comunicação, a análise dos campos da mensagem Generic Object Oriented Substation Event (GOOSE) e a utilização de sistemas de detecção de intrusão. O presente trabalho descreve o desenvolvimento de um Intrusion Detection System (IDS) que atende os requisitos de segurança propostos pelo protocolo IEC-62351, para a identificação de ataques à comunicação realizada por mensagens GOOSE do protocolo IEC-61850, e entre equipamentos do sistema elétrico. Para o desenvolvimento desta aplicação, foram identificados os campos que compõem as mensagens GOOSE, de forma a reconhecer os valores esperados em diferentes situações de operação do sistema elétrico. Determinaram-se padrões de comportamento a serem utilizados para discernir mensagens falsas na rede de comunicação. Instalou-se e configurou-se um sistema operacional de tempo real embarcado na plataforma de desenvolvimento Zynq Board (ZYBO), juntamente com o controlador Open-Mul, para gerenciar a rede de comunicação da subestação, através do protocolo OpenFlow, realizando otimizações para o tráfego multicast. Foi desenvolvido um sistema de detecção e bloqueio de mensagens GOOSE falsas que utiliza o protocolo OpenFlow para controle da rede de comunicação do Sistema Elétrico. Desenvolveu-se ainda um sistema inteligente, utilizando-se uma Rede Neural Artificial (RNA) Nonlinear Autoregressive Model with Exogenous Input (NARX), para predição do tráfego realizado por mensagens GOOSE e detecção de ataques Distributed Deny of Service (DDOS). Os resultados obtidos demonstraram que o protocolo OpenFlow pode ser uma ferramenta interessante para controle da rede, porém, os fabricantes necessitam amadurecer sua implementação nos switches, para que sejam utilizados em produção nas redes de comunicação das subestações. O sistema de predição do tráfego gerado por mensagens GOOSE apresentou benefícios interessantes para a segurança da rede de comunicação, demonstrando potencial para compor um sistema de detecção de ataques DDOS realizado por mensagens GOOSE, na rede de comunicação das subestações de energia elétrica. / The IEC-61850 made it possible to integrate equipments of electric power system substations to a high-speed Ethernet data communication network. Its main goal is the interconnection of IEDs for the automation of processes in an electrical system. The contributions of this protocol for the integration of the control and supervision of the electrical system are diverse, although an Ethernet network exposes the electrical system for cyber attacks. The IEC-62351 states a series of recommendations to provide security to the communication network of the electrical system, such as the communication network management, the analysis of GOOSE messages and the use of intrusion detection systems. This study describes the development of an IDS that meets the security requirements proposed by the IEC-62351 standard to identify attacks on communication between GOOSE messages exchanged by electrical equipment using IEC-61850. For the development of this application, fields of the GOOSE messages were identified, in order to recognize the expected values in different power system operating conditions. Behaviour patterns were determined to detect false messages on the communication network. A real-time embedded operating system on ZYBO was installed and configured, as well as the OpenMul controller to manage the communication network of the substation through the OpenFlow protocol, performing optimizations for multicast traffic. A detection system and block tamper GOOSE messages, using the OpenFlow protocol for control of the electrical system communication network, were developed. In addition, an intelligent system using an Artificial Neural Network (ANN) Nonlinear Autoregressive Model with Exogenous Input (NARX) for predicting of the GOOSE messages traffic and the detection of Distributed Deny of Service attack (DDOS) were also developed. The results obtained show that the OpenFlow protocol may be a valuable tool for network control, however, manufacturers should maturely carry on with its implementation in the switches, so that it be used in substation communication networks. The traffic prediction system of the GOOSE messages presented interesting benefits for the security of the communication network, demonstrating potential to built a DDOS attack detection system performed by GOOSE messages on the communication network of electric power substations.

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Automação). Universidade do Porto. Faculdade de Engenharia. 2011

Thesis (MPA.) --University of Limpopo, 2018 / Despite the adoption of democratic electoral procedures and the establishment of the Independent Electoral Commission (IEC) in post-apartheid South Africa, the strategies for providing voter education in rural areas of the country have not been adequate in terms of creating awareness about democracy and enabling rural citizens to mJlke rational choice during elections (Sadie, Patel, & Baldry 2016:6). It is for this reason that this study was conducted to evaluate the effectiveness of voter education strategies in one of the rural communities in Greater Giyani Municipality, in Limpopo province. This study adopted qualitative exploratory research design. The target groups were the local IEC voter educators and community members. Data was collected using one to one individual interviews, observation and literature review. The results of the study show that the IEC used various strategies to promote voter education. However, the dominant use of media was discredited by the community because of the language barrier, lack of ownership, one-way communication, unaffordability and low level of literacy. It was also found that voter education is not provided continuously as stated in IEC documents while shortage of IEC voter educators and limiting education periods pose other challenges. The study also revealed poor voter education coverage to special groups such as the disabled or the marginalised groups due to lack of capacity to teach them. These findings show that voter education is not as effective as it should be. The study therefore recommends that strategies for voter education be strengthened, especially in rural communities where people live in poverty and poor socio-economic conditions. It is further recommended that the IEC revises voter education strategies and uses those that will benefit more people, such as face to face and home visits, so that people feel free to ask questions. Furthermore, the community recommended that the IEC teaches community stakeholders, who will in turn cascade the information down to community members. The reason for this is that people are likely to feel free to communicate and to ask question because the educators will be known to them. The study further recommends that the IEC improves its staff complement to curb the existing shortage of human power. Further, research on evaluating the knowledge of voters on voting matters will be of outmost importance.

IEC 61508, ISO 26262, DO-254 och CENELEC EN 5012x är alla standarder för utveckling av säkerhetskritiska system. Dessa fyra är applicerbara på bilar upp till 3.5 ton (ISO 26262), flyg (DO-254), tåg (Cenelec EN 5012x) samt IEC 61508 vilket är en standard för flertalet industrigrenar. När ett säkerhetskritiskt system skall implementeras i en FPGA så kan problem uppstå. Detta för att en FPGA ibland räknas till hårdvara men utvecklingen följer samma mönster som mjukvaruutveckling. Detta examensarbetes huvuduppgift är att klargöra hur de olika standarderna ser på FPGA utveckling samt verifiering med hjälp av utökad funktionell verifiering. Uppsatsen är uppdelad i två delar. Den första delen behandlar de säkerhetskritiska standarderna. Vi kommer att gå igenom dessa för att få en översikt samt visa vilka skillnader likheter som finns. Hur ställer de sig till FPGA, hårdvara eller mjukvara. Del två går igenom ett projekt i enlighet med IEC 61508, inklusive metoder för funktionell verifiering ingå. Dessa metoder är ABV (Assertion Based Verification) samt täckningsgrad för verifieringen. Har vi verifierat tillräckligt och vilka krav ställs på ett projekt enligt IEC 61508. I den här delen går vi även igenom hur de olika standarderna ser på FPGA:er samt några rekommendationer gällande FPGA utveckling och säkerhetskritiska system.

Information är idag en värdefull resurs i organisationer som blir mer och mer beroende av sina informationssystem. Information utsätts för olika hot och den behöver skyddas för att organisationer effektivt ska kunna driva sin verksamhet. Ett systematiskt informationssäkerhetsarbete hjälper organisationer att uppnå och upprätthålla en tillräcklig nivå av informationssäkerhet.   Studiens syfte är att undersöka hur informationssäkerhet hanteras inom organisationer i allmänhet i nuläget. En fallstudie har genomförts på Folktandvården, Region Jönköpings län för att undersöka hur Folktandvårdens medarbetare hanterar informationssäkerheten. Dessutom syftar studien till att utvärdera medvetenhet om informationssäkerhet hos medarbetarna på Folktandvården och att presentera förslag på hur hanteringen av personuppgifter kan förbättras i organisationer.  Blandade tekniker har använts för att samla information.  Litteraturstudier inom området informationssäkerhet har genomförts. Empirisk data har samlats in genom en enkätundersökning, intervjuer och skriftliga frågor som har skickats via e-post till utvalda ansvariga som jobbar specifikt med frågor som berör informationssäkerhet inom Folktandvården. Denna studie använder de svenska standarderna SS-ISO/IEC 27001:2014 och SS-ISO/IEC 27002:2014 för att utvärdera informationssäkerhet på Folktandvården, Region Jönköpings län samt att få en bild av hur informationssäkerhet hanteras inom organisationer. Organisationer kan upprätthålla säkerhet i sin informationshantering genom att tillämpa ett ledningssystem för informationssäkerhet (LIS) som bevarar konfidentialitet, riktighet (integritet) och tillgänglighet av information.  Informationssäkerhetsarbetet och införandet av LIS skiljer sig mellan organisationer eftersom de kan påverkas av organisationens behov och mål, storlek och struktur. Fallstudiens resultat visar att Folktandvården, Region Jönköpings län genomför en aktiv hantering av informationssäkerhet. Folktandvården klarar de flesta kraven som ställdes i standarderna. Däremot föreslås det i studien att fler utbildningsprogram ordnas för att öka medvetenheten kring informationssäkerhet. Dessa utbildningsprogram bör uppdateras regelbundet för att det fortsätter att vara i linje med organisatoriska policy och rutiner. Det rekommenderas även att organisationen utför informationsklassning fullt ut enligt den modellen som Folktandvården har. Dessutom rekommenderas att utveckla planeringen av kontinuitet för informationssäkerhet. Resultatet från enkätundersökningen visar att medarbetarna är medvetna om hur de hanterar informationssäkerhetsincidenter och upplever att systemen är tillgängliga för de behöriga. Flera av de förslag som presenterades av denna studie har hörsammats och kommer att leda till vidare arbete inom Folktandvården. Organisationers personuppgifter bör skyddas genom att tillämpa regler enligt gällande författningar. En ansvarig person i organisationen bör ge vägledning till de anställda om sitt ansvar för hantering av personuppgifter. / Information today is a valuable resource for organizations which become more and more dependent on their information systems. Information subject to various threats and the need to be protected in order that organizations can effectively run their business. A systematic information security helps organizations to achieve and maintain a sufficient level of information security. The study aims to investigate how information is managed within organizations in general. A case study has been performed in Folktandvården (the Public Dental Service), Region Jönköping County to investigate how the organization handle information security. In addition, the study aims to evaluate awareness of information security among employees at the business and to present proposals on how to improve handling of personal data. Mixed techniques have been used to gather information. Literature studies in the field of information security has been implemented. The empirical data collected through a questionnaire, interviews and written questions sent by e-mail to managers in Folktandvården. This study uses the standards SS-ISO / IEC 27001:2014 and SS-ISO / IEC 27002:2014 to evaluate the information in Folktandvården, Region Jönköping County and to get a picture of how information is managed within organizations. Organizations can maintain the security of their information by implementing an information security management system (ISMS) that preserves the confidentiality, integrity and availability of information. Information security and ISMS application differs between organizations, which could be affected by the organization's needs and goals, size and structure. Case study results show that Folktandvården, Region Jönköping County implements an active management of information. The organization manages most of the specifications in the standards. However this study proposes to organize more training programs for information security awareness. These programs should be updated regularly in order to continue to be in line with organizational policies and procedures. It is recommended that the organization performs information classification fully in accordance with the model it has. Additionally, it is recommended to develop the planning of continuity for information. The results from the questionnaire show that the employees are aware of how they handle information security incidents and they think that the systems are available for authorized access. Several of the proposals presented by this study have been heeded and will lead to further work in Folktandvården. Organizations' personal information should be protected by applying the rules in accordance with applicable regulations. A responsible person in the organization should provide guidance to employees about their responsibility for the handling of personal data.

Η Real time Specification of Java (RTSJ) ξεπερνάει τους περιορισμούς της Java που την κρίνουν ακατάλληλη για την ανάπτυξη συστημάτων πραγματικού χρόνου. H Real Time Java έχει ήδη χρησιμοποιηθεί στην ανάπτυξη βιομηχανικών συστημάτων ελέγχου με θετικά αποτελέσματα. Ωστόσο, η ευρεία χρήση στην ανάπτυξη εφαρμογών του πεδίου αυτού περιορίζεται σημαντικά από το γεγονός ότι οι μηχανικοί συστημάτων ελέγχου δεν είναι εξοικοιωμένοι με τις σύγχρονες τεχνολογίες ανάπτυξης λογισμικού. Το IEC61499 RTSJ-Based Framework, το οποίο παρουσιάζεται και επεκτείνεται στην παρούσα διπλωματική εργασία αξιοποιεί το νέο IEC61499 πρότυπο, το οποίο είναι βασισμένο στην έννοια του Function Block. Το framework αυτό επιτρέπει στον μηχανικό συστημάτων ελέγχου να δουλέψει στο επίπεδο σχεδίασης χρησιμοποιώντας την ευρέως διαδεδομένη έννοια του FB, εκμεταλλευόμενος το αυτόματα παραγόμενο Real time Java μοντέλο υλοποίησης του συστήματος. Στην παρούσα διπλωματική εργασία αρχικά παρουσιάζονται οι επεκτάσεις που προσφέρει το RTSJ στην standard Java ώστε να μπορεί να χρησιμοποιηθεί σε εφαρμογές πραγματικού χρόνου. Στην συνέχεια παρουσιάζεται το IEC61499 RTSJ-Based Framework και οι επεκτάσεις που έγιναν σε αυτό, ώστε να μπορεί να υποστηριχθεί η ανάπτυξη κατανεμημένων εφαρμογών. Ακολουθεί η ανάλυση της απόδοσης του περιβάλλοντος εκτέλεσης του framework και η περίπτωση χρήσης ενός συστήματος γραμμής παραγωγής, του Festo MPS. / The Real Time Specification of Java (RTSJ) addresses successfully the limitations of Java that make it inappropriate for the development of real time applications.Many positive experiences of using Real Time Java in the control and automation domain have already been reported so far.In spite of the many positive results, the wide use of Java in control and automation domain is prohibited due to the fact that the control engineers are not familiar with current software engineering technologies. The IEC61499 RTSJ-Based Framework, that is presented and extended in the context of this thesis exploits the new IEC61499 standard that is based on the Function Block(FB) concept.This framework allows the control engineer to work in the design level using the already widely accepted concept of FB and transparently use real-time Java for the implementation model of the system. In this thesis the extensions that the RTSJ provides to standard Java are initially presented.Next, the IEC61499 RTSJ-Based Framework is presented as well as the extensions that were added in the context of this thesis in order to support the development of distributed applications.In addition, the performance analysis of the framework's run-time environment is presented as well as the case study of a modular production system the Festo MPS

Actuellement, le marché est caractérisé par un haut niveau de compétitivité et des variations très fréquentes. L'examen critique des systèmes manufacturiers conventionnels révèle que ces systèmes ne sont pas capables de répondre aux exigences imposées au marché actuel; ces exigences sont principalement le coût et la qualité des produits et la réactivité du système. Par conséquent, la mise en place d'un nouveau paradigme de système manufacturier capable de répondre à ces exigences est nécessaire. Le système manufacturier reconfigurable ou le RMS est ce nouveau paradigme; il est censé être assez réactif pour faire face aux changements soudains du marché tout en gardant la qualité des produits à un coût bas. Le principal défi des RMS est leur conception. La plupart des méthodes proposées dans la littérature n'abordent pas le problème de conception d’un RMS dans son ensemble; elles traitent une partie du problème. Dans cette thèse, on propose une méthodologie générique de conception d’un RMS basée sur les principes de l'ingénierie systèmes. Cette méthodologie supporte la conception d’un RMS tout au long du processus de développement. Elle est dérivée principalement de la norme ISO/IEC/IEEE-15288. / Nowadays, the market is characterized by a high level of competitiveness and very frequent and sudden variations in the production context. The critical review of the existing manufacturing paradigms which are the dedicated manufacturing lines DMLs and the flexible manufacturing systems FMSs reveals that these systems are not capable of fulfilling the requirements imposed by the actual market; these requirements are mainly resumed in cost, quality and reactivity. Therefore, the need for a new manufacturing paradigm that could fulfill these requirements has arisen. Reconfigurable Manufacturing System or RMSs is this new paradigm; it is supposed to be reactive enough to cope with the sudden changes of the market while keeping the products quality high with a low cost. The main challenge in RMS is their design. Most of the proposed methods in the literature do not address the RMS design issue as a whole; they treat just part of the problem. Hence, as a contribution, we propose in this paper, a generic RMS design methodology based on systems engineering SE. This methodology will support the RMS design along the development process. It is based specifically on the standard ISO/IEC/IEEE15288.

Les mécanismes moléculaires impliqués dans la régulation du programme génétique de l'épithélium intestinal sont encore à ce jour très peu connus. Dans ce travail, nous avons étudié la régulation des membres de la famille de facteurs de transcription C/EBP en utilisant la lignée épithéliale intestinale de crypte IEC-6 afin de mieux comprendre le rôle de ces gènes dans l'intestin. Dans un premier temps, nous avons vérifié par Northern l'expression des ARNm des C/EBPs suite à la stimulation des cellules avec du sérum qui favorise la prolifération cellulaire et avec un traitement au dexaméthasone qui diminue la prolifération cellulaire. Le sérum induit à des niveaux variables les ARNm des trois isoformes alors que les niveaux d'ARNm de C/EBP? et C/EBP? augmentent rapidement suite à un traitement aux glucocorticoïdes. Par des études de run-on, nous démontrons que le sérum agit surtout par des mécanismes post-transcriptionnels alors que le dexaméthasone influence les niveaux d'ARNm principalement au niveau transcriptionnel. Les analyses par Western nous permettent de constater une induction des trois protéines C/EBP?, ? et ?, parallèle à celle des ARNm suite à une stimulation par le sérum. Par contre, les variations de l'expression de ces trois protéines en présence de dexaméthasone par rapport aux niveaux d'ARNm témoignent d'une certaine régulation post-traductionnelle. La capacité de liaison à l'ADN des C/EBPs augmente suite à la stimulation par le sérum mais ne varie pas suite à un traitement au dexaméthasone, tel que révélé par la technique de rétention sur gel. Des études d'immunofluorescence montrent une localisation nucléaire pour C/EBP? et C/EBP?. Par contre, pour la première fois, nous démontrons une localisation différente de C/EBP?, soit périnucléaire et cytoplasmique, contrairement à une localisation nucléaire chez les hépatocytes et adipocytes. La régulation complexe des C/EBPs dans ces conditions particulières suggère un rôle potentiel de ceux-ci dans la croissance et la réponse inflammatoire des cellules épithéliales intestinales de la crypte.