One of the goals of the COMPASS experience is the study of the nucleon spin structure. Data were taken from a polarized muon beam (160 GeV/c) scattering off a polarized target (6LiD or NH3). In this context, the need of a precise knowledge of quark Fragmentation Functions (final-state hadronisation of quarks q into hadrons h, FFs) was raised. The FFs can be extracted from hadron multiplicities produced in Semi-Inclusive Deep Inelastic Scattering (SIDIS). This thesis presents the measurement of charged hadrons (pions and kaons) multiplicities from SIDIS data collected in 2006. The data cover a large kinematical range: Q2>1 (GeV/c)2, y є [0.1,0.9], x є [0.004,0.7] and W є [5,17] GeV. These multiplicities provide an important input for global QCD analyses of world data at NLO, aiming at the FFs determination. / L'un des objectifs de l'expérience COMPASS est l'étude de la structure du nucléon de spin. Les données ont été prises à partir d'un faisceau de muons polarisée (160 GeV/c) diffuse sur une cible polarisée (6LiD ou NH3). Dans ce contexte, la nécessité d'une connaissance précise des fonctions de fragmentation des quarks (état final du hadronisation de quarks q en hadrons h, FFs) a été soulevée. Le FFs peuvent être extraites de multiplicités de hadrons produits en Semi-Inclusive diffusion profondément inélastique (SIDIS). Cette thèse présente la mesure de la multiplicité de hadrons charge (pions et kaons) à partir de données SIDIS collectées en 2006. Les données couvrent un large domaine cinématique : Q2>1 (GeV/c)2, y є [0.1,0.9], x є [0.004,0.7] and W є [5,17] GeV. Ces multiplicités fournissent un apport important pour l'analyse des données mondiales au 2ème ordre de QCD, visant la détermination de FFs.

In the last decade, the Web 2.0 brought technological changes in the manner of interaction and communication between users and applications, and among applications as well. Rich Internet Applications (RIA) offer user interfaces with a higher level of interactivity, similar to desktop interfaces, embed multimedia contents and minimise the communication between client and server components. Nonetheless, RIAs behave as black boxes that show the information in a user-friendly manner but this information can be only visualised gradually, according to the events triggered by the users on the Web browser, which limits the access of software agents, e.g., Web searchers. In the context of the present Internet, where the value has been moved from the Web applications to the data they manage, the use of open technological solutions is a need. In this way, the Semantic Web was aimed at solving issues of semantic incompatibility among systems by means of standard techniques and technologies (from knowledge representation and sharing to trust and security), which can be the key to solving the issues detected in RIA. Although some solutions exist, they do not cover all the possible types of RIA or they are dependent on the technology chosen for the implementation of the Web application. As a first contribution, this thesis introduces the concept of Semantic Rich Internet Application (SRIA), which can be defined as a RIA that extensively uses Semantic Web technologies to provide a representation of its contents and to reuse existing knowledge sources on the Web. The solution proposed is adapted to the existing RIA types and technologies. The thesis presents the architecture proposed for this type of application, describing its software modules and components. The evaluation of the solution was performed based on a collection of case studies. The development of Web applications, especially in the context of the Semantic Web, is a process traditionally performed manually and, given the complexity of the SRIA applications in this case, it is a process which might be prone to errors. The application of model-driven engineering techniques can reduce the cost of development and maintenance (in terms of time and resources) of the proposed applications, as demonstrated their use in other types of Web applications. Moreover, they can facilitate the adoption of the solution by the community. In the light of these issues, as a second contribution, this thesis presents the Sm4RIA methodology (Semantic Models for RIA) for the development of SRIA, as an extension of the OOH4RIA methodology. The thesis describes the development process, the models (with the corresponding metamodels) and the transformations included in the methodology. The evaluation of the methodology consisted in the development of the case studies proposed. The application of this model-driven methodology can speed up the development of these Web applications and simplify the reuse of external sources of knowledge. Finally, the thesis describes the Sm4RIA extension for OIDE, i.e., an extension of the OIDE CASE tool that implements all the elements of the Sm4RIA methodology.

Expression studies have implicated Fibronectin Leucine Rich Transmembrane protein 2 (FLRT2) in cranial neural crest cell migration and pre-chondrogenic cell condensation during craniofacial skeletogenesis. This aim of this study was to characterize the expression of FLRT2 and its relationship to the extracellular matrix (ECM) in ATDC5 chondroprogenitor cells. Immunofluorescence studies localized FLRT2 to the cell membrane as well as exracellularly, where it colocalized with fibronectin. FLRT2 was identified in the ATDC5-derived ECM after cell extraction. Further to its colocalization with fibronectin, FLRT2 associated with fibronectin-coated beads in cell cultures. Co-immunoprecipitation confirmed that FLRT2 and fibronectin interact, either directly or indirectly. Blocking fibronectin fibril formation in ATDC5 cell cultures demonstrated a concomitant decrease in extracellular FLRT2 accumulation. It appears that FLRT2 may exist in both a membrane-bound and a shed form. Either or both of these forms may participate in cell-ECM interactions in cooperation with fibronectin or other ECM proteins.

Expression studies have implicated Fibronectin Leucine Rich Transmembrane protein 2 (FLRT2) in cranial neural crest cell migration and pre-chondrogenic cell condensation during craniofacial skeletogenesis. This aim of this study was to characterize the expression of FLRT2 and its relationship to the extracellular matrix (ECM) in ATDC5 chondroprogenitor cells. Immunofluorescence studies localized FLRT2 to the cell membrane as well as exracellularly, where it colocalized with fibronectin. FLRT2 was identified in the ATDC5-derived ECM after cell extraction. Further to its colocalization with fibronectin, FLRT2 associated with fibronectin-coated beads in cell cultures. Co-immunoprecipitation confirmed that FLRT2 and fibronectin interact, either directly or indirectly. Blocking fibronectin fibril formation in ATDC5 cell cultures demonstrated a concomitant decrease in extracellular FLRT2 accumulation. It appears that FLRT2 may exist in both a membrane-bound and a shed form. Either or both of these forms may participate in cell-ECM interactions in cooperation with fibronectin or other ECM proteins.

Les mémoires à base de semi-conducteur sont indispensables pour les dispositifs électroniques actuels. La demande croissante pour des dispositifs mémoires fortement miniaturisées a entraîné le développement de mémoires non volatiles fiables qui sont utilisées dans des systèmes informatiques pour le stockage de données et qui sont capables d'atteindre des débits de données élevés, avec des niveaux de dissipation d'énergie équivalents voire moindres que ceux des technologies mémoires actuelles.Parmi les technologies de mémoires non-volatiles émergentes, les mémoires à changement de phase (PCM) sont le candidat le plus prometteur pour remplacer la technologie de mémoire Flash conventionnelle. Les PCM offrent une grande variété de fonctions, comme une lecture et une écriture rapide, un excellent potentiel de miniaturisation, une compatibilité CMOS et des performances élevées de rétention de données à haute température et d'endurance, et peuvent donc ouvrir la voie à des applications non seulement pour les dispositifs mémoires, mais également pour les systèmes informatiques à hautes performances. Cependant, certains problèmes de fiabilité doivent encore être résolus pour que les PCM se positionnent comme un remplacement concurrentiel de la mémoire Flash.Ce travail se concentre sur l'étude de mémoires à changement de phase intégrées afin d'optimiser leurs performances et de proposer des solutions pour surmonter les principaux points critiques de la technologie, ciblant des applications à hautes températures. Afin d'améliorer la fiabilité de la technologie, la stœchiométrie du matériau à changement de phase a été conçue de façon appropriée et des dopants ont été ajoutés, optimisant ainsi la stabilité thermique. Une diminution de la vitesse de programmation est également rapportée, ainsi qu'un drift résiduel de la résistance de l'état de faiblement résistif vers des valeurs de résistance plus élevées au cours du temps.Une nouvelle technique de programmation est introduite, permettant d'améliorer la vitesse de programmation des dispositifs et, dans le même temps, de réduire avec succès le phénomène de drift en résistance. Par ailleurs, un algorithme de programmation des PCM multi-bits est présenté. Un générateur d'impulsions fournissant des impulsions avec la tension souhaitée en sortie a été conçu et testé expérimentalement, répondant aux demandes de programmation d'une grande variété de matériaux innovants et en permettant la programmation précise et l’optimisation des performances des PCM. / Semiconductor memory has always been an indispensable component of modern electronic systems. The increasing demand for highly scaled memory devices has led to the development of reliable non-volatile memories that are used in computing systems for permanent data storage and are capable of achieving high data rates, with the same or lower power dissipation levels as those of current advanced memory solutions.Among the emerging non-volatile memory technologies, Phase Change Memory (PCM) is the most promising candidate to replace conventional Flash memory technology. PCM offers a wide variety of features, such as fast read and write access, excellent scalability potential, baseline CMOS compatibility and exceptional high-temperature data retention and endurance performances, and can therefore pave the way for applications not only in memory devices, but also in energy demanding, high-performance computer systems. However, some reliability issues still need to be addressed in order for PCM to establish itself as a competitive Flash memory replacement.This work focuses on the study of embedded Phase Change Memory in order to optimize device performance and propose solutions to overcome the key bottlenecks of the technology, targeting high-temperature applications. In order to enhance the reliability of the technology, the stoichiometry of the phase change material was appropriately engineered and dopants were added, resulting in an optimized thermal stability of the device. A decrease in the programming speed of the memory technology was also reported, along with a residual resistivity drift of the low resistance state towards higher resistance values over time.A novel programming technique was introduced, thanks to which the programming speed of the devices was improved and, at the same time, the resistance drift phenomenon could be successfully addressed. Moreover, an algorithm for programming PCM devices to multiple bits per cell using a single-pulse procedure was also presented. A pulse generator dedicated to provide the desired voltage pulses at its output was designed and experimentally tested, fitting the programming demands of a wide variety of materials under study and enabling accurate programming targeting the performance optimization of the technology.

La myostatine est un membre de la superfamille du TGF-β (transforming growth factor-β) impliqué dans la régulation négative de la masse musculaire. En effet, l’absence de myostatine (MSTN) chez la souris est responsable d’un phénotype hypermusclé. Depuis, il a été confirmé qu’une baisse de l’activité de la MSTN conduit à une augmentation de la masse musculaire chez d’autres espèces, y compris l’Homme. L’identification de la MSTN et des conséquences de son invalidation sur le développement musculaire ouvre de nombreuses perspectives en médecine humaine. Il existe de nombreuses situations pathologiques qui conduisent à une fonte musculaire importante : c’est le cas pour des maladies génétiques telles que les dystrophies musculaires ou pour d’autres pathologies comme le cancer et le sida. Différentes approches anti-MSTN ont été développées au cours des dernières années, par exemple un anticorps anti-MSTN ou des ligands de la MSTN. L’objectif majeur de ce projet de recherche a consisté à identifier de nouveaux inhibiteurs de la MSTN, en particulier appartenant à la famille de protéines appelées SLRP (Small Leucine Rich Proteoglycans). Il a été mis en évidence que des membres de cette famille, notamment la décorine (DCN) ainsi que des fragments issus de la DCN dont le peptide 31-71, sont capables de se lier à la MSTN en présence de zinc. La DCN peut alors empêcher l’activité de la MSTN en s’opposant à la liaison de cette dernière à son récepteur. Dans ce contexte, nous avons étudié des séquences peptidiques plus restreintes de la DCN murine pouvant interagir efficacement avec la MSTN et des peptides dérivés d’autres SLRP pour leur aptitude à lier la MSTN. Afin de faciliter le criblage in vitro de ces composés, nous avons tout d’abord créé une lignée cellulaire HEK293T exprimant stablement une cassette inductible par la MSTN fusionnée au gène de la luciférase (pCAGA-Luc). Parmi les candidats testés, le peptide mDCN48-71 a été le plus intéressant de par sa forte activité anti MSTN in vitro comparée aux autres, avec un IC50 de 7 µM. Notons également que le peptide mDCN48-71 n’a pas inhibé d’autres membres de la superfamille du TGF-β : TGF-β2, activine A et GDF-11 – ce qui suggère une spécificité d’action du peptide. En outre, des études d’anisotropie de fluorescence ont permis de prouver l’interaction directe du peptide mDCN48 71 avec la MSTN et la dépendance au zinc de cette liaison. Pour finir, nous avons montré que des injections intramusculaires répétées de ce peptide chez le modèle murin dystrophique mdx, conduisent à une augmentation significative de la masse des muscles tibiaux antérieurs injectés de l’ordre de 21 % par rapport aux muscles contrôles. / Myostatin is a member of the transforming growth factor-β (TGF-β) superfamily and a negative regulator of skeletal muscle growth. In 1997, lack of myostatin (MSTN) was related to increased muscle mass in mice. Since then, MSTN has been found in other species including humans. Inhibition of this protein offers opportunities in human medicine for many pathological conditions leading to a significant muscle loss: genetic disorders such as muscular dystrophy as well as other diseases like cancer and AIDS. Recently, several anti-MSTN approaches have been developed such as antibodies against MSTN or naturally occurring proteins that bind to and inactivate MSTN. The aim of this research was to identify novel inhibitors of MSTN, especially belonging to the SLRP (Small Leucine Rich Proteoglycans) family of proteins. Members of this family, including decorin (DCN) and fragments thereof (murine derived peptide mDCN31-71) can bind to MSTN in a zinc-dependent manner. In this context, smaller peptide sequences of mouse DCN and peptides from other SLRP have been studied for their ability to bind MSTN. First, we created a HEK293T stable cell line expressing the luciferase gene under control of a MSTN-inducible promoter (pCAGA-Luc) so as to screen these compounds in vitro. Here we report that the peptide mDCN48-71 shows the stronger activity anti MSTN in vitro among all the peptides tested (IC50 = 7 µM). Furthermore, other members of the TGF β superfamily: TGF β2, activin A and GDF-11 are not inhibited by the mDCN48-71 peptide - which suggests a specificity of its action. By performing fluorescence anisotropy studies, we proved the direct and zinc dependent interaction between peptide mDCN48-71 and MSTN. Finally, we showed that repeated intramuscular injections of this peptide in the dystrophic mdx mouse model led to a significant increase of the injected tibialis anterior muscle mass (21 %) compared to control muscles.

Non-violent resistance group therapy is an innovative way of working with parents whose children are violent and out of control. The programme brings about change on a number of levels, some of which were beyond our expectations. This research aims to both look into the clinical practice and to develop a research method which can do it justice. My aim was to research into those areas which are ‘felt’: beyond the known and the written about. In order to do this I take aspects of the research method portraiture (Lawrence-Lightfoot and Hoffmann Davis, 1997) and bring them together with rich description, rich pictures and arts research practices, so as to create a new qualitative inquiry method which I call ‘rich portraiture’. I describe the development of rich portraiture as a research method and show how I applied it to my practice. At the heart of my dissertation is a complex and layered rich portrait which inquires into the particular experiences of the facilitators of and participants in this groupwork programme (Day and Heismann, 2010). Rich portraiture draws on the performative abilities of clinicians: music, poetry, film, quilt making, painting, dance, sculpture, writing. Detailed narrative portraits of participants and facilitators are located in their social and political context and combined with a juxtapositioning of performance and text which moves into that tacit dimension in which we know more than we can tell (Polanyi, 1966). This is ‘performance in use’ (Cho and Trent, 2009, p 1). My preferred performance method is painting. I made artworks which resonated with the lived experiences of the facilitators and parents who participated in the non-violent resistance therapy programme. As additional layers of performance the paintings were shown in venues where they were viewed by audiences at events during which I spoke and showed films of me working. In this thesis I show how participants and facilitators embody the principles of non-violent resistance and how they perform them in the group. This ‘living’ of non-violent resistance creates change in people’s lives on a number of levels, some of them profound. I argue that there is a gap in the research methods which we use to look at our systemic practice. We constantly seek to creatively enhance our clinical practice so we should also be exploring emerging embodied and performative research practices. This would reflect the shift, in our therapeutic work with clients, towards embodiment (Shotter, 2010), the corporeal (Sheets-Johnstone, 2009) affective or performance turn (Denzin, 2003, 2006). My thesis both describes clinical practice in detail and sets out a new research method.

Este trabalho propõe uma primeira tradução do conjunto de poemas Twenty-One Love Poems (1974-1976) de Adrienne Rich para o português brasileiro e divide-se em dois eixos: o primeiro centra-se nos estudos feministas da tradução, revisando o projeto de Adrienne Rich e o balanço entre a cooperação da tradutora e a tradução como crítica. Discutem-se, caso a caso, as marcações de gênero na tradução, pensando a falácia da neutralidade e as possibilidades relacionadas ao gênero gramatical, com base nos trabalhos de Olga Castro e Myriam Diaz-Diocaretz. O segundo eixo centra-se nas estratégias de recriação de aspectos retórico-formais tais como o contraste entre características antiestéticas e a ambivalência rítmica gerada pela evocação do blank verse, aspectos implicados no ato de re-visão da tradição dos sonetos de amor ingleses performada pela sequência. Com base nos trabalhos de Alice Templeton, Sheila Black, Alicia Ostriker, dentre outras, busca-se mostrar como a postura ambivalente em relação à tradição poética é constituinte do desafio de Rich em sua busca por uma linguagem feminista que alinharia o estético e o político. Para a abordagem da recriação de traços formais, mobilizam-se trabalhos de Paulo Henriques Britto, Mário Laranjeira e Derek Attridge. O conceito de ambivalência que amarra o trabalho recai, por fim, sobre o uso de dêiticos para demarcar espaços, nomear o corpo e fundar a subjetividade autocrítica da voz poemática. Veicula-se a opacidade dos dêiticos, conforme abordada por Giorgio Agamben, a uma postura ambígua frente ao ato adâmico de nomear. / This work presents and discusses a translation of Adrienne Rich\'s set of poems Twenty-One Love Poems (1974-1976) into Brazilian Portuguese. Based on Alice Templeton\'s criticism, it aims to explore the notion of dialogue as well as the re-vision (Rich\'s concept) of the love sonnets\' tradition performed by this sequence of lesbian poems, perhaps the first one written by a major North American poet. The work consists of two parts: the first one focuses on feminist translation studies and the balance between translator\'s cooperation and criticism. It also discusses gender marks on a case-by-case basis, considering the fallacy of neutrality and some possibilities related to grammatical gender, based on the works of Olga Castro and Myriam Diaz-Diocaretz. The second part outlines strategies of re-creation of rhetorical-formal traits such as the anti-aesthetic features and the rhythmic ambivalence given by the poems\' evocation of the blank verse. Formal traits such as these reiterate the challenge faced by Rich in her search for a feminist language in confrontation with the masculine canon, as she reworks traditional poetic forms from another perspective, looking for the dream of a common language, that would align the poetic and the political aspects. This act of translation deals not only with the recreation of traditional Portuguese verse forms, but with the transposition of the notion of tradition to another context as well. This approach is based on the works of Haroldo de Campos, Paulo Henriques Britto, Mário Laranjeira and Derek Attridge.

Este trabalho propõe uma primeira tradução do conjunto de poemas Twenty-One Love Poems (1974-1976) de Adrienne Rich para o português brasileiro e divide-se em dois eixos: o primeiro centra-se nos estudos feministas da tradução, revisando o projeto de Adrienne Rich e o balanço entre a cooperação da tradutora e a tradução como crítica. Discutem-se, caso a caso, as marcações de gênero na tradução, pensando a falácia da neutralidade e as possibilidades relacionadas ao gênero gramatical, com base nos trabalhos de Olga Castro e Myriam Diaz-Diocaretz. O segundo eixo centra-se nas estratégias de recriação de aspectos retórico-formais tais como o contraste entre características antiestéticas e a ambivalência rítmica gerada pela evocação do blank verse, aspectos implicados no ato de re-visão da tradição dos sonetos de amor ingleses performada pela sequência. Com base nos trabalhos de Alice Templeton, Sheila Black, Alicia Ostriker, dentre outras, busca-se mostrar como a postura ambivalente em relação à tradição poética é constituinte do desafio de Rich em sua busca por uma linguagem feminista que alinharia o estético e o político. Para a abordagem da recriação de traços formais, mobilizam-se trabalhos de Paulo Henriques Britto, Mário Laranjeira e Derek Attridge. O conceito de ambivalência que amarra o trabalho recai, por fim, sobre o uso de dêiticos para demarcar espaços, nomear o corpo e fundar a subjetividade autocrítica da voz poemática. Veicula-se a opacidade dos dêiticos, conforme abordada por Giorgio Agamben, a uma postura ambígua frente ao ato adâmico de nomear. / This work presents and discusses a translation of Adrienne Rich\'s set of poems Twenty-One Love Poems (1974-1976) into Brazilian Portuguese. Based on Alice Templeton\'s criticism, it aims to explore the notion of dialogue as well as the re-vision (Rich\'s concept) of the love sonnets\' tradition performed by this sequence of lesbian poems, perhaps the first one written by a major North American poet. The work consists of two parts: the first one focuses on feminist translation studies and the balance between translator\'s cooperation and criticism. It also discusses gender marks on a case-by-case basis, considering the fallacy of neutrality and some possibilities related to grammatical gender, based on the works of Olga Castro and Myriam Diaz-Diocaretz. The second part outlines strategies of re-creation of rhetorical-formal traits such as the anti-aesthetic features and the rhythmic ambivalence given by the poems\' evocation of the blank verse. Formal traits such as these reiterate the challenge faced by Rich in her search for a feminist language in confrontation with the masculine canon, as she reworks traditional poetic forms from another perspective, looking for the dream of a common language, that would align the poetic and the political aspects. This act of translation deals not only with the recreation of traditional Portuguese verse forms, but with the transposition of the notion of tradition to another context as well. This approach is based on the works of Haroldo de Campos, Paulo Henriques Britto, Mário Laranjeira and Derek Attridge.

Afin de caractériser les mécanismes moléculaires sous-jacents au processus d’adhésion des bactéries commensales, nous avons utilisé Streptococcus salivarius comme modèle. Streptococcus salivarius est une bactérie pionière dans la colonisation des surfaces orales chez le nouveau né, et devient par la suite un composant majoritaire du microbiote oral de l'adulte avec un rôle écologique majeur. Nous avons développé une méthode pour identifier, par des tests de criblage phénotypique, les gènes impliqués dans l’adhésion de S. salivarius aux surfaces bactériennes ou de l’hôte. Notre approche a permis d’identifier un ensemble de gènes codant pour des protéines de surfaces, des glycosyltransférases, des transporteurs qui sont impliqués dans les phénomènes d’auto-agréation et / ou de co-agrégation avec d’autres espèces et / ou l’adhésion aux protéines de l’hôte.En particulier, nous avons montré que le système SecA2Y2, qui comprend des gènes codant pour des protéines dédiées à la glycosylation et l'export de protéines de surface riche en sérine (SRRPs), participe aux processus d’agrégation, de formation de biofilms, à l'adhésion in vitro aux protéines de l’hôte et in vivo à la colonisation du tractus digestif de souris. Alors que toutes les bactéries contenant un système similaire possèdent un substrat unique au système, une SRRP, le locus génétique secA2Y2 comprend trois SRRPs qui présentent des rôles complémentaires dans les phénotypes précédement cités. SrpB est spécifiquement impliquée dans la liaison aux cellules epitheliales, tandis que SrpC participe à l’adhésion aux protéines de la matrice extracellulaire et le mucus. De manière atypique, nous avons démontré que le processus de maturation des SRRPs est supporté par glycosyltransférases extra-cluster. Cette étude est le premier rapport indiquant la présence dans une bactérie de trois SRRPs, qui présentent des rôles complémentaires dans l'interaction bactéries-hôte. Bien que le système SecA2Y2 soit principalement associé à la virulence des bactéries pathogènes, il semble être clairement impliqué dans les caractères de commensalité de S. salivarius, tels que la colonisation de ses niches écologiques orales et intestinales. Ce travail offre de nouvelles perspectives sur les mécanismes de colonisation des bactéries commensales. / To characterize molecular mechanisms underlying adhesion of commensal bacteria, we used Streptococcus salivarius (SSAL) as a model. SSAL is among the most important pioneer colonizers of neonatal oral mucosal surfaces, and later becomes a predominant component of the human adult oral microbiota with pre-eminent ecological role. We developed a method to identified, through phenotypic screening assays, genes involved in SSAL adhesion to host or bacterial surfaces. In particular, we showed that the SecA2Y2 system, which comprises genes devoted to glycosylation and export of surface Serine Rich Repeat Proteins (SRRPs), participates to bacterial aggregation, biofilm formation, in vitro adhesion and colonization of mice. While all bacteria containing a similar system possess only one SRRP, the SSAL secA2Y2 locus comprises three SRRPs with complementary role in line with the previous phenotypes. Interestingly, SrpB is specifically involved in the binding to epithelial cells, while SrpC to the extracellular matrix and mucus proteins. We showed that these interactions require glycosylation of both bacterial SRPs and host surfaces. Surprisingly, we demonstrated that this essential process is shared by glycosyltransferases located in other genomic regions. This work is the first report showing the presence in a bacterium of three SRPs, which display complementary roles in bacterial-host interaction. While the SecA2Y2 system is mostly associated to virulence in pathogenic bacteria, it appears to be involved in the expression of commensal traits in SSAL, such as its colonization and its resilience to oral and intestinal niches. This work may offer new insights into the mechanisms of niche establishment (host, microbial communities) of commensal bacteria.