Since decades, hematopoietic stem cell transplantation (HSCT) has become a well established treatment modality for hematological malignancies and non-malignant disorders. Autologous and allogeneic hematopoietic stem cells (HSCs) mobilized into the peripheral blood (PB) have been used as a preferred source of transplantable stem cells1-3. And umbilical cord blood (UCB) has been introduced as a more attractive HSC source for HSCT, because fetal stem cells in UCB are speculated to be more primitive in comparison to adult stem cells. However the limited amount of HSCs is limiting their application for stem cell therapy in clinic. Therefore, people started to utilize extra-embryonic tissue to harvest more fetal stem cells, while people also tried to optimize the clinical protocol to mobilize more adult stem cells out of adult bone marrow. The innovative strategies and feasible procedures were discussed in this thesis. The axis of the chemokine receptor CXCR4 and its ligand SDF-1 is important for trafficking and homing of HSCs. It has already been demonstrated that the bicyclam AMD3100, a CXCR4 antagonist, in combination with G-CSF is able to induce a significant mobilization of CD34+ cells4. And human placenta is a potent hematopoietic niche containing hematopoietic stem and progenitor cells throughout development5. The homing of HSCs to the placenta is probably also mediated by the expression of SDF-1 as demonstrated for the bone marrow niche. In this study (part 1 of the chapter “Results and discussions”), we utilized AMD3100 to mobilize HSCs from placenta. And we can demonstrate that the CXCR4 antagonist AMD3100 mobilise placenta derived CD34+ cells ex utero already after 30 min of incubation and may further enhance the efficacy of harvesting placenta-derived HSC. The alpha4 integrin CD49d is involved in migration and homing of hematopoietic stem cells (HSC). Therapeutic application of natalizumab, an anti-CD49d antibody, in patients with multiple sclerosis (MS) has been associated with increased levels of circulating CD34+ progenitors. In our study (part 2 of the chapter “Results and discussions”), we compared circulating HSCs from MS patients after natalizumab treatment and HSCs mobilized by G-CSF in healthy volunteers, with regard to their migratory potential, clonogenicity and gene expression. CD34+ cells in the blood and marrow of natalizumab-treated patients expressed less of the stem cell marker CD133, were enriched for erythroid progenitors (CFU-E) and expressed lower levels of adhesion molecules. The level of surface CXCR-4 expression on CD34+ cells from patients treated with natalizumab was higher compared to that of CD34+ cells mobilized by granulocyte-colony stimulating factor (G-CSF) (median 43.9% vs. 15.1%). This was associated with a more than doubled migration capacity towards a chemokine stimulus. Furthermore, CD34+ cells mobilized by natalizumab contained more m-RNA for p21 and less MMP9 compared to G-CSF mobilised HSC. Our data indicate that G-CSF and CD49d blockade mobilize different HSC subsets and suggest that both strategies may be differentially applied in specific cell therapy approaches. In order to further improve the clinical outcome of HSC transplantation, many groups are focusing on ex vivo maintain or expand HSC. Unfortunately, the maintenance of HSC in vitro is difficult to achieve because of their differentiation. This is presumably caused by a lack of appropriate cues that are provided in vivo by the microenvironment. Indeed, HSCs located in the bone marrow are interacting with a specific microenvironment referred to as the stem cell niche, which regulates their fate in terms of quiescence, self-renewal and differentiation. An orchestra of signals mediated by soluble factors and/or cell-to-cell contact keeps the balance and homeostasis of self-renewal, proliferation and differentiation in vivo. To investigate the communication between HSCs and the niche, coculture assays with mesenchymal stromal cells (MSCs) were performed in vitro. Here, we can demonstrate that cell-to-cell contact has a significant impact on hematopoietic stem cells expansion, migratory potential and stemness. In this study (part 3 of the chapter “Results and discussions”), we investigated in more detail the spatial relationship between hematopoietic stem cells and mesenchymal stromal cells during ex-vivo expansion. And we defined three distinct localizations of HSCs relative to MSC layer: (i) those in supernatant (non-adherent cells); (ii) cells adhering on the surface of mesenchymal stromal cells (phase-bright cells) and (iii) cells beneath the mesenchymal stromal cells (phase-dim cells). Our data suggest that the mesenchymal stromal cell surface is the dominant location where hematopoietic stem cells proliferate, whereas the compartment beneath the mesenchymal stromal cell layer seems to be mimicking the stem cell niche for more immature cells. Our data provide novel insight into the construction and function of three-dimensional HSC–MSC microenvironments. In summary, we provided a new method to isolate fetal stem cells from extra-embryonic tissue (i.e. placenta) in the first part, then we discussed an innovative strategy with CD49d blockade to improve clinical modality for adult stem cell mobilization in the second part, and finally we investigated HSC maintenance and expansion in vitro and provided feasible way to mimic HSC niche in vitro in the last part. This thesis contributes to HSC-based stem cell therapy in two aspects, i.e. 1) fetal and adult stem cell isolation holding great therapeutic potential for blood diseases; 2) ex vivo stem cell manipulation providing a valuable platform to model HSC niche regulation.

Mercury (Hg) cannot be degraded. Therefore only two principal processes are available for the treatment of Hg-contaminated soil: (1) the separation of Hg from the soil or (2) the stabilisation of Hg within the soil. Prior to selecting a suitable treatment technique, it is necessary to have an understanding of Hg behaviour in contaminated soil, i.e., distribution in particle size fractions, dissolution at different pH and in the presence of chlorides, and mobilisation using various extractants. The thesis aims to evaluate the potential for applying soil washing to decontaminate the Hg-contaminated soil. The Hg contamination originated from inappropriate waste disposal, chlor-alkali process and harbour activities, and the soil was also polluted by other trace elements, i.e., Zn, Cu and Pb, etc. The soil was fractionated from fine to coarse particles to study the effectiveness of physical separation. A pH-static titration ranging from pH 3 to 11 was performed to assess the mobility of Hg in response to pH changes. The chloride influence on Hg mobilisation was studied using an HCl solution of different concentrations as the leachant. Batch leaching tests were used to evaluate Hg solubility in water, and extraction efficiency by various extractants. The extractants derived from wastes were acidogenic leachates generated from biodegradable wastes, and alkaline leachates produced from fly/bottom ashes. The studied soil consisted of dominant coarse-grained fractions, which is usually suitable for particle size separation. However, dry sieving has been shown to be insufficient to separate clean from contaminated soil fractions although the Hg concentrations decreased with increasing particle sizes. The reasons are likely to be: (i) the physical attachment of fines to coarse particles; (ii) the strong chemical bond of soil organic matter (OM) and minerals for Hg. Distilled water could barely mobilise the Hg from the soil, most likely due to firm chemical bonding between the soil and Hg. Despite the fact that enhanced Hg dissolution was observed at pH 5 and 11 in this study, soil washing by pH adjustment was insufficient for Hg removal. The introduction of chlorides did not facilitate the Hg mobilisation either. Retention of Hg in the soil by OM seemed to be predominant over Hg mobilisation by chlorides. Chemical extraction by leachates from wastes as well as EDTA solution and NaOH solutions showed that neither alkaline nor acidic leachates could facilitate Hg removal from the soil. Mercury was firmly bound in the soil matrix and no more than 1.5% of the total Hg could be removed by any of the tested extractants. Future research should therefore focus on the development of Hg immobilisation techniques.

L'étude présentée dans ce mémoire a comparé l’efficacité de trois programmes de réadaptation post-opératoire, avec ou sans mobilisation passive continue (Continuous passive motion: CPM), chez des patients souffrant d'arthrose ayant subi une arthroplastie du genou (AG). Quatre-vingt-un patients ont été randomisés dans trois groupes: 1) physiothérapie usuelle sans CPM, 2) physiothérapie usuelle avec CPM 35 minutes par jour, 3) physiothérapie usuelle avec CPM deux heures par jour. La mesure principale était la flexion active maximale du genou 7 à 8 jours après l'AG (Post-test). Les mesures secondaires étaient l'extension du genou, le questionnaire WOMAC, le test "Timed up and go" et la durée du séjour hospitalier. Les groupes étaient comparables avant l'AG. Au Post-test, la flexion du genou et les mesures secondaires étaient comparables dans les trois groupes. Le CPM n'apporte pas de bienfaits additionnels et ne devrait donc pas être utilisé de routine dans les protocoles de réadaptation post-opératoires chez des personnes opérées pour une première AG. / In this work, a randomized clinical trial was conducted to compare the efficacy of three in-hospital rehabilitation programs with and without continuous passive motion (CPM) on knee flexion, functional ability and length of stay after a primary total knee arthroplasty (TKA). Eighty-one patients who underwent a TKA for a diagnosis of osteoarthritis were randomly assigned to three groups immediately after TKA: 1) control group (CTL): conventional physical therapy (PT) intervention only; 2) experimental group 1 (EXP1): conventional PT intervention and CPM applications for 35 minutes daily; 3) experimental group 2 (EXP2): conventional PT intervention and CPM applications for 2 hours daily. The primary outcome was active knee flexion measured at discharge (7 to 8 days after TKA). Active knee extension, Timed Up and Go, results on the WOMAC questionnaire and length of stay were the secondary outcome measures. The characteristics and outcome measurements of patients in the three groups were similar at baseline, before TKA. No significant difference between the three groups was demonstrated in primary and secondary outcomes at discharge. The results of this study do not support the use of CPM in post-primary TKA rehabilitation programs, as applied in this clinical trial, since it did not further improve knee impairments or disability, nor did it reduce length of hospital stay.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Ce mémoire porte sur la perception des acteurs multisectoriels de la petite enfance concernant le développement langagier des tout-petits et les interventions qu’ils proposent pour le soutenir. L’origine de cette question vient de l’Enquête sur la maturité scolaire des enfants montréalais. En route pour l'école! (DSPM, 2008a) qui révélait que les tout-petits montréalais étaient plus vulnérables dans les domaines du développement cognitif et langagier et des habiletés de communication et connaissances générales que ceux de l’échantillon normatif canadien, jumelée à la préoccupation des acteurs eux-mêmes relativement à cette problématique. Les objectifs sont de décrire le portrait qu’ont ces acteurs du développement langagier des enfants de leur milieu et analyser ces représentations sur le plan de leur articulation problème – solution. Pour y répondre, un cadre conceptuel écologique mettant en relation quatre niveaux d’influence (enfant, famille, voisinage, environnement général) et cinq axes d’intervention a été conçu. La méthodologie adoptée fut une étude de cas qualitative à base d’analyses documentaires et d’entrevues (n=10) auprès des six secteurs engagés dans l’intervention intersectorielle en petite enfance dans un CSSS montréalais. Les résultats montrent que ces acteurs connaissent les facteurs influençant le développement langagier des tout-petits. Les interventions actuelles ou souhaitées sont cohérentes avec les écrits scientifiques et partiellement stratégiques par rapport aux facteurs de risques identifiés. Des actions doivent toutefois être posées pour soutenir davantage les jeunes familles, dont celles visant à hausser la qualité du voisinage ou encore, l’accès à des services publics de qualité. / This thesis examines perceptions of intersectoral stakeholders in early childhood regarding language development in young children, and the initiatives they suggest to support such development. The question originates from a survey on the school readiness of Montréal children, Enquête sur la maturité scolaire des enfants montréalais. En route pour l'école! (DSP, 2008a), which revealed that, with regard to language development and communication skills, young Montréal children were more vulnerable than the Canadian normative sample. It also stems from stakeholders’ concerns regarding this issue. The goals are to describe the representation of language development held by these stakeholders and to analyse their conceptualisation of the problem and the solution to language development. An ecological conceptual framework was developed, comprising four levels of influence (child, family, neighbourhood, overall environment) and five areas of intervention. The methodology was a qualitative case study based on a literature synthesis and interviews (n=10) carried out in six sectors involved in early childhood intersectoral initiatives in a Montréal Health and Social Services Centre (CSSS). Results show that stakeholders are aware of the factors influencing language development in young children. Current or desired initiatives correspond with the literature and are mostly strategic with respect to identified risk factors. However, actions must be taken to provide more support to young families, including actions designed to improve neighbourhoods and enhance access to quality public services.

No description available.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Cette thèse examine le processus de mobilisation pour des étudiants en formation professionnelle et ses relations avec la constitution des buts de leur activité et les caractéristiques des dispositifs et des situations de formation rencontrées. Pour cela, nous adoptons une approche par l'activité des étudiants en situation de formation afin de nous démarquer des approches de la " motivation " développées par la psychologie et des approches en termes de " rapport au savoir " développées en sociologie. Nous nous appuyons sur le cadre théorique de l'activité élaboré par Rubinstein (2007) pour développer le concept de mobilisation proposé initialement par Charlot, Bautier et Rochex (1992). Nous avons réalisé un recueil de données de type ethnographique et longitudinal auprès de trois classes d'étudiants inscrits dans une formation de Brevet de Technicien Supérieur en Agroalimentaire dans trois établissements différents. Notre analyse se déroule en trois temps : * caractérisation des environnements, dispositifs et situations de formation rencontrés par les étudiants des trois établissements ; * approche statistique de l'état de mobilisation pour les différentes situations de formation ; * monographies longitudinales concernant quatre étudiants. Nous montrons que l'état de mobilisation pour une classe de situations est préfiguré par quelques situations passées, présentes et projetées pour chaque individu. Mais cet état s'actualise en fonction des caractéristiques des situations rencontrées, dont certaines jouent un rôle important : cohérence des finalités de la situation avec la finalité professionnelle affichée par la formation ; contenus abordés en tant que savoirs outils (Douady, 1983) pour l'action en situation professionnelle ; tâches appelant à déployer des actes de création réelle (Rubinstein, 2007) ; ... Les étudiants sont mobilisés pour des situations par lesquelles leur personnalité se réalise dans et par les actions déployées : elle se constitue et se donne à voir à l'individu et aux autres. Ces situations sont au fondement de la constitution de buts stables pour leur activité et d'un itinéraire de toute une vie pour l'individu. Les étudiants n'ont pas de meilleurs résultats scolaires pour les situations de formation pour lesquelles ils sont mobilisés. Les étudiants sont démobilisés lorsque leur activité est morcelée et ne parvient plus à réguler les actions au regard de leurs buts, des caractéristiques de leur personnalité et des conditions et exigences des situations. Leurs résultats scolaires sont inférieurs à leurs résultats moyens pour les situations où ils sont démobilisés. En conclusion nous proposons des développements pour la théorie de l'activité élaborée par Rubinstein et pour le cadre théorique de la didactique professionnelle. Nos résultats permettent de développer ceux présentés par Rochex dans son ouvrage " Le sens de l'expérience scolaire " (1995). Ils nous amènent à proposer des pistes de réflexion pour penser les questions de l'alternance, de l'orientation et du décrochage scolaire en formation professionnelle.

La présente thèse aborde la question de la migration de retour sous l’angle peu commun du transfert de connaissances, au travers de la création d’entreprise, susceptible d’être novatrice, dans l’hypothèse où l’expatriation du migrant qualifié, aux fins de formation supérieure dans un pays comparativement plus développé, peut être l’occasion pour celui-ci de maîtriser un savoir ou un savoir-faire profitable à la mise en place d’affaires à plus forte valeur ajoutée dans son pays d’origine. De plus, notre travail ambitionne de pouvoir au final renseigner sur des approches opportunes pour la mobilisation des compétences diasporiques, –en faveur d’investissements servant par exemple les plans d’émergence industrielle de ce pays d’origine qu’est le Maroc– au travers de recommandations basées sur notre revue de la littérature théorique et empirique, appuyée par une étude de terrain originale et une analyse formalisée de ses résultats, suivant une démarche hypothético-déductive prédictive. Ceci, en vue de contribuer à faire face à cette rareté des études qui, comme la nôtre, font appel aux variables qualitatives (ouvertes) plus riches –pour une compréhension en profondeur du sujet– mais aussi plus complexes à traiter et à interpréter que celles se limitant aux variables quantitatives. Il s’agit ainsi, d’étudier une tranche de la diaspora marocaine de France et son degré de contribution au développement socio-économique du Maroc, de par son potentiel entrepreneurial souvent synonyme d’une plus grande valeur ajoutée à ce pays en développement, grâce aux qualités propres à cette tranche. La problématique a, en effet, pour population cible : les diplômés et étudiants originaires du Maroc qui préparent ou qui ont fait des études supérieures et/ou disposent d’une qualification professionnelle acquise en France, et dont l’éventuel projet de retour serait associé ou pas à une création d’entreprise. L'objectif recherché est donc l'étude du retour, lié à la probable intention d’entreprendre, et delà celle des variables explicatives pouvant affecter cette décision et/ou ce choix positivement ou négativement, en en repérant les incitations et les freins par l’examen d’un échantillon représentatif qui nous permettra de faire ressortir les motivations et contraintes mais aussi les opportunités qui se présentent à un candidat au retour au pays et qui serait éventuellement porteur d’un projet de création d’entreprise innovante ou non au Maroc. / This thesis addresses the issue of return migration, in the unusual terms of knowledge transfer through business creation, which may have the potential to drive innovation from the host to the home country, in the event that the expatriation of skilled migrant, for the purpose of achieving higher qualification in a comparatively more developed country, may be an opportunity for this migrant to master knowledge or know-how beneficial to value added businesses development in its country of origin. Our work also aims to provide guidance on formulating appropriate approach for mobilizing diaspora entrepreneurship to promote economic growth and development (that could, for example, be in harmony with the Moroccan national plan for industrial emergence) through recommendations, based on critical review of the theoretical and empirical literature, supported by an original field study and its formal analysis results, using an hypothetico-deductive approach, associated with econometric modeling for predictive purposes by simulations. In an attempt to contribute to fill the lack of studies, like ours, that take the challenge of making use of (open-ended) qualitative variables richer –for a deeper understanding of the subject– but also more complex to treat and interpret than quantitative variables. So, we study a portion of the Moroccan diaspora of France and its degree of contribution to the socio-economic development of Morocco, through its entrepreneurial potential, that may be synonymous with greater added value in this “developing” country thanks to the unique qualities of this portion. The problem statement, or thesis, has indeed as target population: graduates & students originating from Morocco who prepare or have completed graduate studies and /or have a professional qualification acquired in France, and whose return project may or may not be associated with starting a business in Morocco. The aim is the study of return linked to the probable intention to undertake a business project, and therefore the examination of explanatory variables that could affect, positively or negatively, this decision and/or choice, by identifying its incentives and brakes through the analysis of a representative sample that will allow us to highlight motivations and constraints, but also the opportunities that present themselves to a candidate for return who is possibly bearer or not of an innovative business creation project in Morocco.

This thesis lays focus on the Young Socialist Movement (ungsocialisterna) and their mobilisation in Stockholm between 1903 and 1910. In line with social movement research the theoretical concepts of mobilisation structure and resource mobilisation are used to examine the Young Socialists local clubs mobilisation and its prerequisites. The results show that the mobilisation structure of the Young Socialists in Stockholm was characterised by a fragmented organisational framework, wherein local clubs operated independently. This underscored the importance of the groups social network in their mobilising efforts and collaboration between the clubs. The ideological stance was ambiguous, and various radical ideas influenced the mobilisation structure of the group. Due to a lack of tangible resources, human and intangible resources played an essential role in the Young Socialists mobilisation efforts. Over time the decentralised organisational structures and diverse ideological affiliations came to hinder the Young Socialists effectiveness in mobilising towards their goal: the socialist revolution. This study sheds light on the practices and mobilising process of an often overlooked group that was highly influential in shaping the early labour movement in Sweden. It also underscores the importance of a unified mobilisation structure for social movements.