The primary focus of my PhD is to quantify the spatial distribution of star-forming environments from optical to radio wavelengths using data from the Hubble Space Telescope, the Very Large Telescope, the Spitzer Space Telescope, the Herschel Space Observatory, and the Caltech Submillimeter Observatory. Towards the end of my PhD study I have developed theoretical models. With these observational and theoretical avenues I have led a series of research projects to (1) quantify the initial spatial structure of pre-stellar cores and proto-stars, (2) test whether massive stars can form in isolation or not, (3) and develop a theoretical model on how young massive clusters form. These research projects have been fruitful as my collaborators and I have shown that pre-stellar cores and stars form in a smooth continuum of surface densities from a few to thousands of stars per pc^2. These two works have important implications on our understanding of what a young stellar cluster is and how star forming environments can evolve to form field star populations or gravitationally bound clusters. In my second study my collaborators and I found evidence for isolated massive star formation in the active star forming region 30 Doradus, in the Large Magellanic Cloud. The result impacts the field of the initial mass function and star formation models. Massive stars forming in isolation is consistent with a stochastically sampled initial mass function. Additionally, the result would put constraints on theoretical models on massive star formation. Continuing my work on massive star forming environments my collaborators and I have developed a theoretical model on how young massive clusters form. From the models we argue that feedback energies can be contained by the gravitational potential well of the massive progenitors. Furthermore, we predict the physical properties the massive cluster progenitors in terms of initial gas mass, radii and flux brightness to enable a search for these objects in Galactic plane surveys and upcoming telescopes. Using the common thread of spatial distribution analysis of star formation I describe my future research plans, which entails studies on extragalactic scales in the conclusion.

Previous studies have shown that thermal feedback from protostars plays a key role in the process of low-mass star formation. In this thesis, we explore the effects of protostellar heating on the formation of stellar clusters. We describe new methods for modelling protostellar accretion luminosities and protostellar evolution in calculations of star formation. We then present results of a series of numerical simulations of stellar cluster formation which include these effects, and examine their impact. We begin by investigating the dependence of stellar properties on the initial density of molecular clouds. We find that the dependence of the median stellar mass on the initial density of the cloud is weaker than the dependence of the thermal Jeans mass when radiative effects are included. We suggest that including protostellar accretion luminosities and protostellar evolution may weaken this dependence further, and may account for the observed invariance of the median stellar mass in Galactic star-forming regions. Next, we investigate the effects of including accretion feedback from sink particles on the formation of small stellar groups. We find that including accretion feedback in calculations suppresses fragmentation even further than calculations that only include radiative transfer within the gas. Including feedback also produces a higher median stellar mass, which is insensitive to the sink particle accretion radius used. Finally, we compare calculations of small stellar clusters which model the evolution of protostars using a live stellar model with those which use a fixed stellar structure. We find that the dynamics of the clusters are primarily determined by the accretion luminosities of protostars, but that the relative effects of protostellar evolution depend on the accretion rate and advection of energy into the protostar. We also demonstrate how such calculations may be used to study the properties of young stellar populations.

La présente thèse s’insère dans le domaine de la recherche exploratoire sur les enjeux didactiques de la formation initiale et continue des enseignants d’anglais L2 dans le contexte algérien : entre les objectifs institutionnels et les attentes des enseignants. L’étude s’intéresse à la formation initiale et continue des futurs enseignants telle qu’elle est prescrite par la tutelle et telle qu’elle est mise en œuvre par l’institut de formation. Appuyée sur les données collectées à partir des différents outils utilisés à cet effet, à savoir quatre questionnaires, deux interviews et l’analyse du cursus de formation, la recherche met en lumière le décalage qui existe entre le prescriptif et le descriptif de la formation. Le monde dans lequel nous vivons est en perpétuelle métamorphose ; celui de l’éducation l’est autant. Les changements et les réformes auxquelles nous assistons ces temps-ci sont dictés par le seul souci de bien-faire, dans le cadre de la mondialisation. Néanmoins, les réformes entamées dans le système éducatif algérien ne peuvent atteindre leurs objectifs que si elles sont menées de manière réfléchie, intelligente, méthodique et rationnelle. Dans une société en pleine transformation, la formation professionnelle des enseignants s’avère une nécessité urgente. Ces enseignants doivent développer une pratique réflexive : une posture fondamentale, parce que la capacité d’innover, de négocier et de réguler leur pratique passe impérativement par une réflexion sur l’expérience, favorisant la construction de savoirs nouveaux. / The present thesis fits into the field of the exploratory research on the didactical issues of the initial and in-service trainings of teachers of English as a foreign language in the Algerian context: between institutional objectives and the teachers’ expectations. The study focuses on the initial and in-service trainings of the future teachers as it is required by the employer and as it is carried out by the training institute. Founded on the collected data from the various tools used for the purpose, namely the questionnaires, the interviews and the initial training curriculum analysis, the research highlights/sheds light on the gap between the prescriptive and the descriptive trainings. The world in which we live is in perpetual metamorphosis that of education is the same. The changes and reforms we are witnessing these days are dictated solely by the desire to do well in the context of globalization. Nevertheless, the reforms undertaken in the Algerian educational system cannot achieve their goals unless they are conducted in a thoughtful, intelligent, methodical and rational manner. In a changing society, training of professional teachers is an urgent need. These professional teachers have to develop reflective practice, a basic posture, because the ability to innovate, negotiate and its practice necessarily involves a reflection on experience, encouraging the construction of new knowledge

Made available in DSpace on 2016-06-02T19:35:40Z (GMT). No. of bitstreams: 1 DissDFS.pdf: 1835832 bytes, checksum: 39f238f754aac5a8cc12333b6a9bc649 (MD5) Previous issue date: 2004-03-10 / Financiadora de Estudos e Projetos / Les représentations sociales des professeurs sur le corps humain et ses répercussions dans l enseignement de Sciences Naturelles, constituent un étude dans la perspective moscovicienne. En reférence à une sorte de connaissance socialement élaborée et partagé, un sabor pratique qui dévoile des valeurs, croyances afectivités, symboles, certitudes et interprétations, sur un objet donné et qui a comme fonction première, orienter des communications et des conduites. Cette recherche propose accèder aux représentations sociales, des ces professerus-là, sur le corps humain mettant en rapport les contextes de leur formation, de leu contenu constitué et de l articulation avec la pratique pédagogique. 108 professeurs de Sciences Naturelles dans l enseignement publique du 1o cicle à Uberlândia ont été observés. Les donnés ont été obtnus à partir d association livre des mots, de triage hiérarchisés sucessives et interviews semi-structurés.Lés térmoignages recuellis ont été soumis à l analyse de contenu Bardin (1977), sous forme de statistique et a rendu possible la délimitation de classes sémantique. Le contenu des discours obtenus à partir des interviews a été classé en catégories et ont permis l accès critique au sens des comunications, son contenu expries ou implicite. Le corp humain y est compris sous le paradgme de la corporéité, que le considére comme um tout, indissociable, irréductible qui manifest toutes les possiblités de l homme dans son intégralité. Les analyses realisées ont pu constater que les représentations sociales sur le corps humain dans le groupe des professeurs ont été centrés autours d un noyau central qui met en valeur les éléments de nature biologique cependant, colorés des nuances périphériques d ordres sociales, culturelles, afectives, psichologiques. Au niveau individuel elles s organisent dans un noyau central qui met en relief des éléments de dimensions de mêmes caracteristiques, mélangés toutefois aux éléments d ordre biologique. Ces constations entraîntent la necessité de repenser l enseignement par rapport le corps humain, en classes de Sciences Naturelles. Il faut contempler le corps, pendant que expression de la nature humaine, dans unce perspective holistique, comme un grande système d interaction. Il faut que le professeur ait conscience et considére de façon plus critique ses propers représentations, pour que sés concepts ne soyent plus jamais présentés, comme si le corps humain fût fragmenté, morcelé, dissocié même du monde. Les représentations sociales et leus implications sur la pratique pédagogique ici recherchées, fournissent des subsides significatifs pour des changements precieux au jour à jour de l enseignant. Ce qui est souhaitable quand on désire promouvoir une meilleure qualité à apprentissage de Sciences Naturelles. / As representações sociais dos professores sobre corpo humano e suas repercussões no ensino de Ciências Naturais constitui um estudo das representações sociais na perspectiva moscoviciana. Estas referem-se a uma modalidade de conhecimento socialmente elaborada e partilhada, um saber prático, que revela valores, crenças, símbolos, afirmações, interpretações sobre um dado objeto e apresentam, como função principal, orientar comunicações e condutas. O objetivo desta pesquisa é acessar as representações sociais dos professores sobre corpo humano, aproximando-se dos contextos de sua formação, do seu conteúdo constituído e da sua articulação com a prática pedagógica dos professores investigados. Os sujeitos desta pesquisa compreendem um total de 108 professores de Ciências Naturais do Ensino Fundamental da rede pública de ensino da cidade de Uberlândia-MG, que foram submetidos às técnicas de associação livre de palavras, de triagens hierarquizadas sucessivas e de entrevistas semi-estruturadas. Os dados coletados foram submetidos à análise de conteúdo Bardin (1977) e, sofreram um tratamento estatístico, que possibilitou a delimitação de classes semânticas. O conteúdo dos discursos oriundos das entrevistas foi organizado em um sistema de categorizações, que permitiu acessar criticamente o sentido das comunicações, seu conteúdo manifesto ou implícito. O corpo humano é compreendido sob o paradigma da corporeidade, que considera o corpo como um todo indissociável, irredutível e que manifesta as possibilidades do homem integral. As análises realizadas possibilitaram constatar que as representações sociais sobre corpo humano, no grupo de professores, estruturam-se em torno de um núcleo central, que destaca elementos de natureza biológica, coloridos de matizes periféricos de naturezas sociais, culturais, afetivos, psicológicos. Em nível individual, elas se organizam num núcleo central que ressalta elementos de dimensões sociais, culturais, psicológicas, afetivas, de corpo humano, mesclados aos elementos de ordem biológica. Essas constatações implicam a necessidade de repensar o ensino do corpo humano nas aulas de Ciências Naturais. É preciso que o corpo, como expressão da natureza humana, seja contemplado numa perspectiva holística, compreendida como um grande sistema de interação. Para que o processo ensino-aprendizagem em Ciências Naturais concorra para esta finalidade, é imprescindível que o professor tenha consciência e aprecie criticamente as suas próprias representações, para que elas não contribuam, junto aos alunos, para a construção de uma concepção de corpo humano fragmentado e dissociado de si, dos outros e do mundo. As representações sociais e suas implicações sobre as ações pedagógicas, investigadas nesta pesquisa, oferecem subsídios significativos para mudanças na prática pedagógica, o que é desejável, quando se almeja promover melhor qualidade para o ensino das Ciências Naturais.