Bumblebees are ecologically and economically important as pollinators, but some species are suffering severe declines and range contractions. In this thesis, three cryptic bumblebee species are studied to elucidate differences in their distribution, ecology and population genetics. As a result of their high morphological similarity, very little is known about the lucorum complex species: B. lucorum, B, cryptarum and B. magnus. In this study, their distributions across Great Britain were assessed using molecular methods, revealing that B. lucorum was the most abundant and most generalist of the three species, whereas B. magnus was the rarest and most specialised, occurring almost exclusively on heathland. Additionally, both B. magnus and B. cryptarum were more likely to be present at sites with cooler summer temperatures. Cryptic species represent interesting models to investigate the levels of niche differentiation required to avoid competitive exclusion. Characterising the niches of these species at a single site across the flight season revealed differences along three niche dimensions: temporal activity, weather sensitivity and forage-resource use. These species exhibited asymmetric niche overlap; a combination of ecological divergence and spatio-temporal heterogeneity may contribute to maintaining them in sympatry. Population genetic studies can be highly informative for understanding species ecology and for conservation management. The differences in habitat specialisation exhibited by these bumblebee species provide the opportunity to test conflicting hypotheses about links between dispersal and ecological specialisation: are habitat specialists selected to have low or high dispersal ability? Based on microsatellite analysis, the generalist B. lucorum had high levels of genetic diversity and little population structure across large spatial scales. The habitat specialist B. magnus had the lowest genetic diversity but similar levels of population differentiation to the moderate generalist, B. cryptarum. However, unlike B. cryptarum, B. magnus population differentiation was not affected by geographic distance, suggesting that this specialist species may maintain effective dispersal across large scales despite being restricted to a fragmented habitat. Bergmann’s rule is a well-known ecogeographic rule describing geographical patterns of body size variation, whereby larger endothermic species are found more commonly at higher latitudes. Ectotherms, including insects, have been suggested to follow converse Bergmann’s gradients, but the facultatively endothermic nature of bumblebees makes it unclear which pattern they should adhere to. This thesis reports caste-specific differences in body size between the three lucorum complex species in agreement with Bergmann’s rule: queens and males of B. cryptarum and B. magnus, which were found more commonly at higher latitudes and at sites with cooler temperatures, were larger than those of B. lucorum. Population genetic studies of invertebrates generally require the destruction of large numbers of individuals, which is often undesirable. Testing a variety of faecal collection and DNA extraction methods demonstrated that it is possible to obtain DNA of sufficient quality for genotyping from bumblebee faeces, without harming the individuals. This method would be valuable for studies of rare or declining bee species, for queens in reintroduction projects, and may be applicable to other arthropods. Overall this thesis contributes substantially to our knowledge of the ecology and population genetics of three important pollinator species. It provides data to inform species conservation, as well as understanding of ecosystem functioning and population dynamics. Furthermore, it successfully uses these cryptic species as a model to test several fundamental ecological theories.

Submitted by Maike Costa (maiksebas@gmail.com) on 2016-08-16T14:17:09Z No. of bitstreams: 1 arquivo total.pdf: 3410642 bytes, checksum: 841c67dbd66adfc644f39ae218a5f6ce (MD5) / Made available in DSpace on 2016-08-16T14:17:09Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 3410642 bytes, checksum: 841c67dbd66adfc644f39ae218a5f6ce (MD5) Previous issue date: 2016-04-01 / The present study targeted at analyzing the niche of infant development inside the familial microsystem and in daycare centers, within a non-urban context. For such, we interviewed 30 mothers and 21 daycare center educators of children aged between 06 and 36 months old, from three non-urban contexts, based on sub-existence agriculture in the city of Petrolina-PE. As theoretical contribution, it was based on the ecocultural perspective of human development, consisting of a complex and dynamic process produced by the individual, and the physical, social, and cultural environment such as interactive systems which make the analysis of the context in which people live indispensable, for each culture and context, in particular, lead to different development processes. We highlight, in this research, the analysis of the niches of infant development in the familial and daycare center microsystems whose environments are comprehended as physical and social, the educational practices, and the parental ethno-theories, taking into account the influences that they have over the child’s development. As tools for this research, we used a socio-demographic questionnaire, a semi-structured interview plan, a structured interview with questions regarding the infant development niches in the familial and daycare center context, and unsystematic observations. The interviews were transcribed and submitted to the content theme analysis, including the material’s exploration and pre-analysis as well as the codification, by using descriptive words and phrases, taking into consideration the criteria for exhaustiveness, representativeness, homogeneity, and pertinence. Later on, the frequency of the mothers’ responses in each category and subcategory was realized, and the average percentage based on the total number of responses obtained in each one of them, calculated. Where the socialization goals are concerned, the responses were also discussed based on the categories as established by Harwood et al., aiming at the understanding of the cultural dimensions highlighted by the participants. Outcomes indicated that mothers, in the majority, show positive conceptions about the child’s development, characterizing them as active, intelligent, and caring, and consider healthcare, affection, and education as relevant factors for infant development; they get involved with ludic interactions toward their children and get concerned with domestic accidents; they use inductive practices in the children’s behavioral control; they set socialization goals turned to the autonomous-relational model and centered strategies as priorities; they expect their children to be able to contribute to society as of the practice of social values; they consider daycare centers as institutions that must promote formal education and the child’s behavioral control. The educators, in turn, pointed education and affection as the main aspects for infant development, built up as of interactive processes; they conceive childhood in a non-urban context as being exposed to danger, and going through affection and economic shortages, leading daycare centers to the duty of giving these children basic needs, stimulating their development, and controlling their behavior. Moreover, they highlight the necessity of a greater partnership between the family and daycare center; they hope the children to achieve socialization goals and societal contributions related to social expectations, followed by autonomy, centralizing the strategies for the achievement of such goals. Results turn out to be discussed as of characteristics of the participants’ eco-cultural context, and considerations by Psychology authors of infant Development. / el presente estudio objetivó analizar el nicho de desarrollo infantil, en el microsistema familiar y de la guardería, en contexto no urbano. Para tanto, fueron entrevistadas 30 madres y 21 educadoras de guarderías, de niños en edades entre 06 y 36 meses, de tres contextos no urbanos, basados en la agricultura de subsistencia, del municipio de Petrolina-PE. Como aporte teórico, se usó como base la perspectiva ecocultural del desarrollo humano, que lo comprende como un proceso complejo y dinámico, producido por el individuo y por el medio físico, social y cultural, como sistemas interactivos, que tornan indispensable el análisis del contexto en que viven las personas, pues, cada cultura y contexto en particular conducen a diferentes procesos de desarrollo. Se destacan, en este estudio, el análisis de los nichos de desarrollo infantil en los microsistemas familiar y guardería, comprendidos como ambiente físico y social, además de las prácticas de educación y las etnoteorías parentales, teniendo en vista las influencias que ejercen sobre el desarrollo del niño. Como instrumentos, fueron utilizados un cuestionario sociodemográfico, una guía de entrevista semiestructurada, una entrevista estructurada con cuestiones relativas a los nichos de desarrollo infantil en el contexto de la familia y de la guardería, y observaciones asistemáticas. Las entrevistas fueron transcritas y sometidas al análisis temático de contenido, comprendiendo la exploración y la pre análisis del material, así como la codificación mediante el uso de palabras y frases descriptoras, considerando los criterios de exhaustividad, representatividad, homogeneidad y pertenencia. Posteriormente, fue realizada la frecuencia de respuestas de las madres en cada categoría y subcategoría y calculado el porcentual medio con base en el número total de respuestas obtenidas en cada una de ellas. En lo que se refiere a las metas de socialización, las respuestas también fueron discutidas con base en las categorías establecidas por Harwood et al., con el fin de comprender las dimensiones culturales enfatizadas por los participantes. Los resultados apuntaron que las madres, en su mayoría, presentan concepciones positivas sobre el desarrollo de los niños, caracterizándolos como activos, inteligentes y cariñosos y consideran los cuidados con salud, afectividad y educación como factores relevantes para el desarrollo infantil; se involucran en interacciones lúdicas con los hijos y se preocupan con accidentes domésticos; usan las prácticas inductivas en el control del comportamiento de los niños; priorizaron metas de socialización dirigidas para el modelo autónomo-relacional y estrategias centradas en sí y en el contexto en que viven; esperan que los hijos puedan contribuir para la sociedad a partir de la práctica de valores sociales; y consideran la guardería como institución que debe promover la educación formal y el control del comportamiento del niño. En relación a las educadoras, estas apuntan la educación y la afectividad como principales aspectos para el desarrollo infantil, construidos a partir de procesos interactivos; conciben la infancia en el contexto no urbano como expuesta al peligro y carente, afectiva y económicamente, teniendo la guardería y el educador las funciones de suplir las necesidades básicas de esos niños, estimular su desarrollo y controlar el comportamiento. Además, destacan la necesidad de mayor acompañamiento entre familia y guardería; anhelan para los niños metas de socialización y contribuciones para la sociedad relacionadas a las expectativas sociales, seguidas de la autonomía, centralizando en sí las estrategias para el alcance de esas metas. Esos resultados son discutidos a partir de las características del contexto ecocultural de los participantes y de las consideraciones de autores de la Psicología del Desarrollo Infantil. / O presente estudo objetivou analisar o nicho de desenvolvimento infantil, no microssistema familiar e da creche, em contexto não urbano. Para tanto, foram entrevistadas 30 mães e 21 educadoras de creches, de crianças na faixa etária entre 06 e 36 meses, de três contextos não urbanos, baseados na agricultura de subsistência, do município de Petrolina-PE. Como aporte teórico, baseou-se na perspectiva ecocultural do desenvolvimento humano, que o compreende como um processo complexo e dinâmico, produzido pelo indivíduo e pelo meio físico, social e cultural, como sistemas interativos, que tornam indispensável a análise do contexto em que vivem as pessoas, pois, cada cultura e contexto em particular conduzem a diferentes processos de desenvolvimento. Destacam-se, neste estudo, a análise dos nichos de desenvolvimento infantil nos microssistemas familiar e creche, compreendidos como ambiente físico e social, além das práticas de educação e as etnoteorias parentais, tendo em vista as influências que exercem sobre o desenvolvimento da criança. Como instrumentos, foram utilizados um questionário sociodemográfico, um roteiro de entrevista semiestruturada, uma entrevista estruturada com questões relativas aos nichos de desenvolvimento infantil no contexto da família e da creche, como também observações assistemáticas. As entrevistas foram transcritas e submetidas à análise temática de conteúdo, compreendendo a exploração e a pré-análise do material, assim como a codificação mediante o uso de palavras e frases descritoras, considerando os critérios de exaustividade, representatividade, homogeneidade e pertinência. Posteriormente, foi realizada a frequência de respostas das mães em cada categoria e subcategoria e calculado o percentual médio com base no número total de respostas obtidas em cada uma delas. No que se refere às metas de socialização, as respostas também foram discutidas com base nas categorias estabelecidas por Harwood et al., com o intuito de compreender as dimensões culturais enfatizadas pelos participantes. Os resultados apontaram que as mães, em sua maioria, apresentam concepções positivas sobre o desenvolvimento da criança, caracterizando-as como ativas, inteligentes e carinhosas e consideram os cuidados com saúde, afetividade e educação como fatores relevantes para o desenvolvimento infantil; envolvem-se em interações lúdicas com os filhos e preocupam-se com acidentes domésticos; usam as práticas indutivas no controle do comportamento das crianças; priorizaram metas de socialização voltadas para o modelo autônomo-relacional e estratégias centradas em si e no contexto em que vivem; esperam que os filhos possam contribuir para a sociedade a partir da prática de valores sociais; e consideram a creche como instituição que deve promover a educação formal e o controle do comportamento da criança. Em relação às educadoras, estas apontam a educação e a afetividade como principais aspectos para o desenvolvimento infantil, construídos a partir de processos interativos; concebem a infância no contexto não urbano como exposta ao perigo e carente, tanto afetiva quanto economicamente, tendo a creche e o educador as funções de suprir as necessidades básicas dessas crianças, estimular seu desenvolvimento e controlar o comportamento. Além disso, destacam a necessidade de maior parceria entre família e creche; almejam para as crianças metas de socialização e contribuições para a sociedade relacionadas às expectativas sociais, seguidas da autonomia, centralizando em si as estratégias para o alcance dessas metas. Esses resultados são discutidos a partir das características do contexto ecocultural dos participantes e das considerações de autores da Psicologia do Desenvolvimento Infantil.

Submitted by LINA MARIA DELGADO GARCIA (linadelgadomvz@gmail.com) on 2016-06-03T17:50:42Z No. of bitstreams: 1 Diss_LinaMDelgadoGarcia_PPG_MV_FMVZ.pdf: 5259973 bytes, checksum: 96b8449017ba967633f1d9ef9da7c741 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-06-06T18:25:40Z (GMT) No. of bitstreams: 1 delgado-garcia_lm_me_bot.pdf: 5259973 bytes, checksum: 96b8449017ba967633f1d9ef9da7c741 (MD5) / Made available in DSpace on 2016-06-06T18:25:40Z (GMT). No. of bitstreams: 1 delgado-garcia_lm_me_bot.pdf: 5259973 bytes, checksum: 96b8449017ba967633f1d9ef9da7c741 (MD5) Previous issue date: 2016-05-02 / No final dos anos 60, os experimentos em proliferação celular anunciaram a neurogênese adulta em mamíferos. Três décadas depois a relação entre neurogênese e células-tronco neurais (NSCs) foi estabelecida. Atualmente, as NSCs são objeto de pesquisas na medicina como modelo de estudo de múltiplos estados anormais e distúrbios orgânicos, além de se propor como uma estratégia em condições com poucas alternativas terapêuticas. Contudo o desenvolvimento destas terapias depende do entendimento dos mecanismos moleculares, celulares e biológicos que controlam a neurogênese e as NSCs. Assim, o objetivo deste trabalho foi o estudo das teorias no funcionamento dos nichos neurogênicos e as NSCs com ênfase na proliferação, migração e diferenciação, além da descrição dos aspectos celulares in vitro dos precursores neurais (NPCs) dos nichos neurogênicos dos mamíferos. Os nichos são regiões do sistema nervoso adulto que apresentam neurogênese pela presença das NSCs e um microambiente celular apropriado. Nos mamíferos existem pelo menos dois nichos, a zona subventricular (SVZ) dos ventrículos laterais e a zona subgranular (SGZ) do hipocampo. Os estudos revisados demostram que existem diferenças e semelhanças no comportamento das NSCs nos nichos neurogênicos adultos, levando a que a proliferação, migração e diferenciação seja menos efetiva quando comparada com o desenvolvimento embrionário. Para finalizar, se descreveu o protocolo para isolamento e cultivo dos NPCs e seus aspectos celulares. Os NPCs proliferaram como populações heterogêneas multipotentes. Após a diferenciação, as células migraram e apresentaram características morfológicas e imunofenotípicas de células neurais imaturas, com o predomínio de células gliais. Em conjunto, os NPCs in vitro mimetizam os aspectos gerais da neurogênese. / In the late 60`s, the experiments on cell proliferation announced adult neurogenesis in mammals. Three decades later, the link between neurogenesis and neural stem cells (NSCs) was recognized. Currently, NSCs are the matter of research in human and veterinary medicine as a model of multiple abnormal states and organic disorders, in addition to be proposed as a strategy for diseases and conditions with few therapeutic alternatives. However, the successful development of these therapies depends on the understanding of molecular, cellular and biological mechanisms that control neurogenesis and NSCs. Therefore, the aim of this work was the study of the theories on neurogenic niches and NSCs with focus in proliferation, migration and differentiation, beyond the description of the cellular aspects of in vitro neural precursors cells (NPCs) of the neurogenic niches of the mammals. The neurogenic niches are regions of the adult nervous system which display complete neurogenesis because of the presence of NSCs and an appropriate cell microenvironment. In mammals, there are at least two neurogenic niches, the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the hippocampus. The reviewed studies showed that exists differences and similarities in the behavior of the adult NSCs in the neurogenic niches that lead to less effective proliferation, migration and differentiation; when compared with the embryonic development. Finally, was described the protocol for isolation and cultivation of NPCs and their cellular aspects. NPCs proliferated as heterogeneous multipotent populations. Differentiation analyses showed that cells migrated and showed morphological and immunophenotypical characteristics of immature cells with the predominance of glial cells. Overall, NPCs effectively reproduce the general aspects of neurogenesis.

Orientador: Rogério Martins Amorim / Resumo: No final dos anos 60, os experimentos em proliferação celular anunciaram a neurogênese adulta em mamíferos. Três décadas depois a relação entre neurogênese e células-tronco neurais (NSCs) foi estabelecida. Atualmente, as NSCs são objeto de pesquisas na medicina como modelo de estudo de múltiplos estados anormais e distúrbios orgânicos, além de se propor como uma estratégia em condições com poucas alternativas terapêuticas. Contudo o desenvolvimento destas terapias depende do entendimento dos mecanismos moleculares, celulares e biológicos que controlam a neurogênese e as NSCs. Assim, o objetivo deste trabalho foi o estudo das teorias no funcionamento dos nichos neurogênicos e as NSCs com ênfase na proliferação, migração e diferenciação, além da descrição dos aspectos celulares in vitro dos precursores neurais (NPCs) dos nichos neurogênicos dos mamíferos. Os nichos são regiões do sistema nervoso adulto que apresentam neurogênese pela presença das NSCs e um microambiente celular apropriado. Nos mamíferos existem pelo menos dois nichos, a zona subventricular (SVZ) dos ventrículos laterais e a zona subgranular (SGZ) do hipocampo. Os estudos revisados demostram que existem diferenças e semelhanças no comportamento das NSCs nos nichos neurogênicos adultos, levando a que a proliferação, migração e diferenciação seja menos efetiva quando comparada com o desenvolvimento embrionário. Para finalizar, se descreveu o protocolo para isolamento e cultivo dos NPCs e seus aspectos celulares. O... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the late 60`s, the experiments on cell proliferation announced adult neurogenesis in mammals. Three decades later, the link between neurogenesis and neural stem cells (NSCs) was recognized. Currently, NSCs are the matter of research in human and veterinary medicine as a model of multiple abnormal states and organic disorders, in addition to be proposed as a strategy for diseases and conditions with few therapeutic alternatives. However, the successful development of these therapies depends on the understanding of molecular, cellular and biological mechanisms that control neurogenesis and NSCs. Therefore, the aim of this work was the study of the theories on neurogenic niches and NSCs with focus in proliferation, migration and differentiation, beyond the description of the cellular aspects of in vitro neural precursors cells (NPCs) of the neurogenic niches of the mammals. The neurogenic niches are regions of the adult nervous system which display complete neurogenesis because of the presence of NSCs and an appropriate cell microenvironment. In mammals, there are at least two neurogenic niches, the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the hippocampus. The reviewed studies showed that exists differences and similarities in the behavior of the adult NSCs in the neurogenic niches that lead to less effective proliferation, migration and differentiation; when compared with the embryonic development. Finally, was described the proto... (Complete abstract click electronic access below) / Mestre

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-17T12:40:15Z No. of bitstreams: 1 adrianoviniciodasilvadocarmo.pdf: 2816680 bytes, checksum: 29d44c65450304afd000d3902ab824a0 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-02-26T13:03:31Z (GMT) No. of bitstreams: 1 adrianoviniciodasilvadocarmo.pdf: 2816680 bytes, checksum: 29d44c65450304afd000d3902ab824a0 (MD5) / Made available in DSpace on 2016-02-26T13:03:31Z (GMT). No. of bitstreams: 1 adrianoviniciodasilvadocarmo.pdf: 2816680 bytes, checksum: 29d44c65450304afd000d3902ab824a0 (MD5) Previous issue date: 2014-03-17 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Esta é uma pesquisa descritiva que investiga a estrutura e o funcionamento do website educacional Portal do Professor, seção Espaço da Aula, tomando como unidades de análise sua ferramenta de criação de planos de aula (Criar Aula) e as páginas resultantes do trabalho de criação de aulas (disponíveis em Sugestões de Aula). Para isso, considera-se que: 1) websites (e suas páginas) podem ser caracterizados pelos meios de representação que utilizam (texto, imagem, animação, som, vídeo etc.) e pelas conexões/interligações que realizam com suas páginas internas ou com outras páginas na Web e 2) websites podem ser entendidos como Nichos Cognitivos, que são constituídos por diversos artefatos, que, além de cognitivos, apresentam propriedades semióticas específicas, concebidas ou oportunisticamente usadas para melhorar, ou simplesmente alterar, certas competências cognitivas. Durante a pesquisa, foi definida uma amostra aleatória de 70 aulas para aplicação de um instrumento quantitativo. Após isso, analisando o mapeamento resultante, foram listadas 7 aulas para a análise qualitativa. A discussão dos resultados levou a algumas afirmações: 1) a criação de uma aula online é um processo educacional, cognitivamente desenvolvido e apoiado por um nicho já construído (o Criar Aula); 2) as aulas já prontas são produtos educacionais que são publicadas no Sugestões de Aula, compondo um repositório que opera como um nicho cognitivo à medida que oferece possibilidades de ação (escolha de aulas diversas) mediante determinadas contingências educacionais; 3) a colaboração docente em um website, como um processo de cognição distribuída, é (ou possui condições de ser) potencializada, visto a facilidade de interconexão entre diversos artefatos e pessoas, formando nichos cognitivos específicos. / This is a descriptive study that investigates the structure and functioning of the educational website Portal do Professor section Espaço da Aula, taking as their units of analysis the tool for creating lesson plans (Criar Aula) and the resulting pages of the work of creating lesson plans (available at Sugestões de Aula). For this, it is considered that: 1) websites (and its pages) can be characterized by means of representation used (text, image, animation, sound, video, etc.) and the connections/interconnections that carry out with your internal pages or with other Web pages and 2) websites can be understood as Cognitive Niche, which consist of various artifacts, which, in addition to cognitive, have specific, designed or used opportunistically semiotic properties to improve, or simply change certain cognitive skills. During the research, was set a random sample of 70 lesson plans to application of a quantitative instrument. After that, analyzing the resulting mapping, 7 lesson plans were listed for qualitative analysis. The discussion led to some statements: 1) the creation of an online lesson plan is an educational process, cognitively developed and supported by a niche already built (the Criar Aula), 2) the ready lesson plans are educational products that are published in Sugestões de Aulas, composing a repository that operates as a cognitive niche as offering possibilities for action (choice of several lesson plans) under certain educational contingencies, 3) teacher collaboration on a website as a process of distributed cognition, is (or is able to be) potentiated, because facilitates the interconnection between various artifacts and people forming specific cognitive niches.

Achieving a transition to sustainability and decrease the environmental impact of building is part of Sweden's sustainability goals. Authorities and policy makers have a big responsibility to promote and facilitate this transition, but how this is to be achieved is not as readily answered. Using the multi-level perspective on socio-technical transitions, this thesis investigates the conditions for sustainability transitions in Swedish building by learning from the case of earthen and straw home builders. Qualitative mixed methods research, including questionnaires and semi-structured interviews was carried out to explore drivers and barriers for innovative sustainable building in Sweden. Findings suggest that there are barriers for innovative sustainable building in Sweden that might slow down the sustainability transition process, not in terms of regulation but in practices and norms in the current socio-technical regime.

Pendant la régénération musculaire, les cellules souches musculaires (dites satellites) prolifèrent de manière symétrique et asymétrique. La ségrégation non aléatoire des brins d'ADN est un mécanisme associé à la division asymétrique, souvent en lien avec des destins cellulaires distincts. Quand ce phénomène apparaît et comment il est régulé durant la régénération musculaire sont des points clés sur lesquels je me suis focalisée durant ma thèse. Afin d'étudier le rôle de signaux extracellulaires dans les décisions du type de division, nous avons utilisé des micropatrons de motifs symétrique et asymétrique recouverts de matrice extracellulaire. Nous avons alors montré que les fréquences de divisions asymétriques peuvent être modulées selon la forme du motif. En outre, nous décrivons une fenêtre de temps in vivo au cours de la régénération musculaire où une sous population de cellules satellites peut passer d'une division symétrique à asymétrique. Une analyse transcriptionnelle de ces cellules a permis d'identifier des gènes candidats potentiellement impliqués dans la régulation de cette transition. Nous avons testé l'effet de quelques protéines associées à ces gènes incorporées dans des niches artificielles 2D. Des données préliminaires suggérèrent que des signaux extrinsèques (protéine de la matrice extracellulaire et rigidité du substrat) combinés à une signalisation intracellulaire peuvent réguler la balance entre prolifération et différentiation. L'ensemble de ces données de thèse montre l'importance d'un dialogue entre le microenvironnement et les signaux intracellulaires dans la régulation du comportement des cellules souches. / During muscle regeneration, muscle stem (satellite) cells proliferate symmetrically and asymmetrically. Non-random segregation of old and new template DNA strands (NRDS) is one mechanism associated with an asymmetric cell division, and this is often linked with distinct daughter cell fates. How this frequency is modulated and when during tissue remodelling are key questions that are the focus of my thesis project. To address the role of extrinsic cues in NRDS and cell fate decisions, we used micropatterns coated with extracellular matrix and designed with symmetric and asymmetric topological motifs. We show that the frequency of NRDS and transcription factors asymmetry (Pax7, stem; Myogenin, differentiated) can be modulated depending on the topology of the adhesion cues of the micropattern. Moreover, we show that a temporal switch occurs in vivo during early muscle regeneration from symmetric to asymmetric DNA segregation in a subpopulation of satellite cells. Gene expression profiling of symmetrically and asymmetrically dividing cells allowed the identification of candidate regulators that might impinge on this regulatory transition. Some candidate genes were assayed in a high throughput screen that was on 2D artificial stem-cell niches. Preliminary data show that extrinsic cues (ECM protein and substrate stiffness) combined with signalling pathways can regulate the balance between proliferation and differentiation in a context dependent manner. Taken together, this thesis project shows that the interplay between microenvironment and intracellular signalling impacts on the regulation of stem cell behaviour.

Les théories relatives à la biodiversité contrastent fortement quant au rôle qu’elles accordent aux différences de traits écologiques entre espèces (théorie des niches) ou à la stochasticité démographique (théorie neutre de la biodiversité) pour expliquer l’organisation des communautés d’espèces compétitrices. Les espèces en compétition pour une ressource pulsée permettent de tester à relativement court terme ces théories : dans le cadre de la théorie des niches, les espèces en compétition devraient présenter de fortes différences de traits les conduisant à exploiter différemment la ressource pulsée; elles devraient alors répondre démographiquement de manière différente aux fortes fluctuations en ressources et leurs dynamiques populationnelles devraient être asynchrones. Au contraire, dans le cadre de la théorie neutre, les espèces ne devraient pas présenter de différences majeures dans leurs caractères associés à l’exploitation de la ressource variable; elles devraient alors répondre de la même manière aux pulses et leurs dynamiques populationnelles devraient être synchronisées. Nos travaux, centrés sur quatre espèces du genre Curculio en compétition pour l’exploitation des glands de chêne, permettent de mettre en évidence (i) qu’un fort partitionnement global de leurs niches est assorti de dynamiques populationnelles asynchrones. (ii) Cependant, ils montrent également que deux des quatre espèces compétitrices apparaissent très similaires quant aux caractères étudiés et présentent des dynamiques de population synchronisées. Les résultats, dans leur ensemble, fournissent donc l’un des premiers arguments empiriques en faveur d'une théorie unifiée de la biodiversité / Understanding the organization of communities composed of competing species, and notably their biodiversity, has led to two theories that sharply contrast with each other about the role primarily assigned either to the differences in ecological traits among the species (niche theory) or to the demographic stochasticity (neutral theory of biodiversity). Species competing for a pulsed resource allow testing the two theories in short-term studies: the niche theory predicts that differences should exist in the traits of such species, which should allow them taking advantage of the resource in various ways; the species should thus respond differently to the fluctuations in the availability of the resource, resulting in asynchronous population dynamics. In contrast, the neutral theory predicts that the trait differences possibly existing between the species should not impact the way they use the variable resource; the species should then respond similarly to the pulses and their population dynamics should be synchronized. Our work, focusing on four phytophagous insect species (Curculio spp.) that compete for oak acorns (Quercus spp.), (i) show evidence of a clear, global niche partitioning combined with asynchronous population dynamics (ii) but points out that two of these species show similar ecological traits and display synchronized population dynamics. Overall, these results therefore provide one of the first empirical arguments in favor of a unified theory of biodiversity

La croissance des activités anthropiques au cours du dernier siècle a contribué à la dispersion et à l’établissement d’espèces végétales non-natives à travers le monde. Ces espèces sont des moteurs importants de changements environnementaux puisqu’elles ont la capacité de modifier les communautés végétales natives notamment à travers la compétition. Puisque les humains sont un des principaux moteurs d'introduction, d'établissement et de propagation d'espèces non-natives et que toute mesure de gestion, pour être efficace, dépend d’une acceptabilité sociale, il est nécessaire de comprendre les perceptions et les choix relatifs à leur utilisation et à leur gestion. La présente recherche a servi à : i) comprendre les perceptions des différentes parties prenantes envers les différentes espèces végétales non-natives de l’île Navarino, une zone tampon de la Réserve de la Biosphère du Cap Horn (RBCH) dans la région subantarctique chilienne ainsi qu’à ii) identifier les dynamiques de niches et les zones à haut potentiel d’établissement (i.e. points chauds) de quatre de ces espèces, qui serviront ensemble d’outils à la gestion de la RBCH. Pour répondre au premier objectif, sept groupes de parties prenantes ont été identifiés (i.e. résident-e-s, résident-e-s aîné-e-s, conservationnistes, membres de la marine, touristes, membres de la communauté autochtone yaghan, employé-e-s des services publics), à l’intérieur desquels 21 entrevues semi-dirigées ont été conduites. Pour répondre au deuxième objectif, les données de présence globales et régionales de quatre espèces végétales herbacées non-natives particulièrement abondantes i.e. Bellis perennis, Cerastium fontanum, Taraxacum officinale et Trifolium repens ainsi que les données climatiques associées ont servi à développer des modèles de distribution des espèces utilisant la méthode d’entropie maximale (MaxENT). En ce qui concerne le premier objectif, les résultats ont révélé des lacunes dans la compréhension du concept d’espèces non-natives parmi les différentes parties prenantes dans le contexte local. D’autre part, les analyses ont révélé de nombreuses valeurs positives associées aux espèces de plantes non-natives à Navarino, notamment la valeur esthétique. Aussi, cette recherche a montré que la plupart des parties prenantes étaient indifférentes à la gestion des espèces de plantes herbacées non-natives. En ce qui concerne le deuxième objectif, les résultats ont révélé un changement de niche habituellement utilisée par les espèces liée au climat moins favorable de Navarino ainsi qu’une forte plasticité pour les quatre espèces mentionnées ci-haut. Néanmoins, les quatre populations auraient atteint l’équilibre à Navarino. Finalement, la combinaison des modèles globaux et régionaux montre que les zones de points chauds se situent plus particulièrement sur la côte sud de l’île et s’étendent au Nord dépendamment des espèces. Basés sur les résultats obtenus, nous suggérons donc (i) de sensibiliser davantage les parties prenantes aux plantes non-natives, (ii) d'intégrer leurs valeurs dans les décisions de gestion futures et (iii) de surveiller les distributions des espèces végétales non-natives à Navarino à des fins de prévention en considérant l’emplacement stratégique de l'île de Navarino comme un tremplin potentiel pour la dispersion des espèces non-natives vers l'Antarctique. / The growth of human activities over the last century has contributed to the dispersal and establishment of non-native plant species around the world. These species are important drivers of environmental change since they have the capacity to modify native plant communities, especially through competition. Since human are the main drivers of introduction, establishment and spread of non-native species and since management strategies need to take into account public attitudes to be successful, it is necessary to understand the perceptions and choices regarding their use and management. The present study aimed to: i) understand the perceptions of different stakeholders towards the different non-native plant species of Navarino Island, a buffer zone of the Cape Horn Biosphere Reserve (CHBR) in the Chilean sub-Antarctic region and ii) identify niche dynamics and high potential establishment areas (i.e. hotspots) of four of these species, which together will serve as multidisciplinary tools for the CHBR management. To address the first objective, seven stakeholder groups were identified (i.e residents, elder residents, conservationists, marine members, tourists, Yaghan community members, public service employees), within which 21 semi-directed interviews were conducted. To address the second objective, global and regional occurrences of four of the most abundant species, i.e. Bellis perennis, Cerastium fontanum, Taraxacum officinale and Trifolium repens and associated climatic data were used to develop species distribution models using the maximum entropy method (MaxENT). Regarding the first objective, results of this study revealed shortcomings in the non-native concept understanding among stakeholders in a local context. On the other hand, the analyzes revealed many positive values associated with non-native plant species in Navarino, notably the aesthetic value. Nevertheless, this study showed that most stakeholders were indifferent to the management of non-native herbaceous plant species. Regarding the second objective, results revealed a niche shift usually used by species due to the less favorable climate of Navarino Island as well as high plasticity for the four plant species mentioned above. However, plant populations might have reached the equilibrium. Finally, the combination of global and regional models shows that hotspots areas are located more particularly on the south coast of the island and extend to the north depending on the species. Based on the results obtained in this study, we therefore suggest (i) increasing awareness of non-native plant among stakeholders, (ii) integrating their values into future decisions, and (iii) preventing dispersal of non-native plant species through Antarctica by monitoring species distribution on Navarino.

This research took its point of departure in the aspiration of large-scale change of the construction industry, where existing industry structures has been frequently criticized. To facilitate innovation and change in the Swedish construction industry, a strategic innovation program has been established based on the idea that research, innovation, and development should manifest itself through the mobilization of collaborative and actor-driven networks. Using a strategic innovation program to support inter-organizational collaboration and actor-driven change is a fairly new phenomenon in the context of construction and thus the subject of inquiry for this research. From a theoretical point of view, this can be understood in terms of a transition of a socio-technical system. Therefore, the purpose was to gain a deeper understanding of how a socio-technical transition of the construction industry could be facilitated. The research presented in this licentiate thesis has been conducted between September 2019 – March 2022 and has been a part of a research project called Program Generic Measurement Methods. This research has a qualitative inquiry and has been designed as a longitudinal case study to understand, and follow, this process of change. The data that has been collected consist of document collection, structured interviews, semi-structured interviews and an autoethnographic approach including observations and self-reflection. Actor-network theory, and specifically the concepts related to the translation process and black boxing, has been used as an analytical framework and facilitated the analysis of the collected data. This thesis increases the understanding of how a socio-technical transition in construction could be facilitated by analyzing the events that lead to the development of the strategic innovation program as well as events from the operational part of the program. Key actors in these processes are identified as well as their roles in a transition of the construction industry. The results indicates that this is far from a linear process that contains a lot of negotiation between participating actors. During this process, the role of digitalization changes when the intention of the program moves from its initiators to the actors engaged in different technological niches. A better integration of academia is asked for due to the complexity that digitally driven transition processes brings. Moreover, actors in the construction industry are encouragedto engage in technological niches to interact and collaborate in new, or modified, ways outside traditional construction activities since it stimulates learning and facilitate a deeper understanding of the challenges that actors in the construction process face together.