The main purpose of this thesis was to investigate the fit between four achievement goals, personal goal attributes and self-regulation strategies, and the generalisation of goal-strategy patterns to (1) different life domains (academic and physical activity settings), (2) two cultures (individualistic/the UK and collectivistic/Romania) and (3) over time, in two contexts (academic and sport university settings) in the UK. Additionally, differences between high level English and Romanian athletes in self-construals (individualism versus collectivism), achievement goals and self-regulation processes was investigated in one study. Method. The participants in the four studies of this thesis were: English university students (N = 591; study 1), English university athletes and exercise participants (N = 294 and N = 288, respectively; study 2), English and Romanian elite/sub-elite athletes (N = 91, N = 109 respectively; study 3a), Romanian university students involved in sport at elite and sub-elite levels (N = 196; study 3b), and English university student-athletes (N= 295; study 4). Three main questionnaires were used: the Achievement Goals Questionnaire (AGQ; Elliot & McGregor, 2001) (studies 1, 3b, and 4) and the Achievement Goals Questionnaire for Sport (AGQ-S; Conroy, Elliot & Hofer, 2003) (studies 2, 3ab and 4) measured four achievement goals in academic and sport settings, respectively (mastery-approach, mastery-avoidance, performance-approach and performance-avoidance goals); the third questionnaire, the Goal Systems Assessment Battery (GSAB; Karoly & Ruehlman, 1995) (all studies) required participants to state their most important personal goal, and measured two goal attributes (efficacy and value) and five self-regulation strategies used during goal pursuit (planning, self-monitoring, social comparison, self-reward and self-criticism). The fourth questionnaire, was the Self-Construal Scale-Revised (SCS-R; Hardin, 2006) which measured individualistic and collectivistic self-definitions in study 3a. Studies 1, 2 and 3a and 3b employed a correlational design, structural equation modelling analyses, and multivariate and univariate analyses of covariance (study 3a only), while study 4 employed a longitudinal design, latent growth curve analyses and structural equation modelling. Studies 1 and 2 Results. The goal-strategy models identified in education (study 1), sport and exercise (study 2) in the UK were very similar to each other, and consisted of both positive and negative paths (see figure A overleaf). Furthermore, in study 1, the total sample was divided into two samples according to the difficulty and specificity of personal goals: students in sample 1 (N = 325) set easy and vague goals, while students in sample 2 (N = 266) set difficult and specific goals. The model found in the total sample was tested again simultaneous in these two samples in order to ascertain the potential moderation effects of goal difficulty and specificity. As the model was invariant across groups it was concluded that personal goal difficulty/specificity was not a moderator of achievement goal relations with self-regulation processes. Finally, in study 2 Map relations with planning/self-monitoring was fully and partially mediated by goal efficacy and value in the sport and exercise domains, respectively. Study 3a and 3b Results. In study 3a, Romanian athletes had higher collectivistic self-construals than English athletes, while the two groups were similar in individualism. After controlling for collectivism, Romanian athletes, regardless of sport type (individual or team sport) had higher scores than English athletes on Pap and Pav goals, social comparison and self-motivation strategies (self-reward and self-criticism); and Romanian team sport athletes had higher scores on Map and planning/self-monitoring than their English counterparts. In study 3b the goal-strategy models identified in moderately competitive academic and physical activity settings in an individualistic West European culture (UK) were tested in highly competitive academic and elite sport settings in a collectivistic East European culture (Romania). The academic and sport domain models identified in Romania were similar to each other, and to those found in the UK. The following differences in model paths were noted in Romania: in the academic domain, four paths were not significant (Map and Mav to efficacy, efficacy to self-reward, and social comparison to self-criticism); and a new negative path was identified, from Map to social comparison; in the sport domain, five paths were not significant (Mav to efficacy, Pap to efficacy and social comparison, efficacy to reward and social comparison to self-criticism) and three new paths emerged, two positive paths, Pav to social comparison, and efficacy to planning/self-monitoring, and one negative path from efficacy to criticism. The positive path from Pav to social comparison (found in highly competitive sport settings) represents the most notable difference between the UK and Romanian models. Study 4 Results. The goal-strategy models identified in academic and sport contexts in studies 1 and 2 (described earlier) emerged again in these settings in study 4 (minus the path from efficacy to reward in both settings, and efficacy to criticism in academia) at three measurement times (start, middle and end of academic year/competitive season). Therefore, the model was stable over time. Unconditional growth curve analyses showed that, during one year, achievement goals and self-regulation processes followed different patterns of change: Map and Pav goals declined, while Pap and Mav goals were stable in education, and all goals declined in sport settings; goal commitment (a composite measure of goal efficacy and value) declined and planning/self-monitoring remained stable (in both settings); social comparison and self-motivation (a composite measure of self-reward and self-criticism) increased in education, while in sport the former was stable and the latter declined . Finally, associative growth curve models showed that in both domains: 1) temporal changes in Map were positively related to changes in goal commitment and planning/monitoring, and changes in the latter were associated with changes in self-motivation; 2) changes in Pap, social comparison and self-motivation were positively related; and 3) Mav changes were not related to changes in SR processes. Conclusion. This thesis advocates a conceptualisation of achievement goals as a dynamic, cyclical interplay between situated reasons, standards and self-regulated action; 2) an exploration of goal standards dimensions beyond the mastery-performance focus with the reason-standard complex; and 3) an expanded achievement motivation and self-regulation model, including the why (achievement goals), the what (personal goals/goal setting), and the how (self-regulated action), where the focus of enquiry is sifted from the correlates to the mechanisms of achievement goal effects.

Ce travail de thèse est dédié à la visualisation par microscopie optique des transitions de phases, thermo- et photo-induites dans des monocristaux à transition de spin. L’étude des cristaux du composé [{Fe(NCSe)(py)2}2(m-bpypz)] a permis de montrer la possibilité de contrôler la dynamique de l’interface HS/BS (haut spin/bas spin) par une irradiation lumineuse appliquée sur toute la surface du cristal ou de manière localisée. Les investigations expérimentales menées sur l’effet de l’intensité de la lumière sur la température de transition ont mis en évidence d’une part l’importance du couplage entre le cristal et le bain thermique, et d’autre part le rôle de la diffusion de la chaleur dans le monocristal. En parallèle, un modèle basé sur une description de type Ginzburg-Landau, a permis de mettre sur pied une description de type réaction diffusion des effets spatio-temporels accompagnant la transition de spin dans un monocristal. Celui-ci a permis d’identifier et de comprendre le rôle des paramètres pertinents entrant en jeu dans le contrôle du mouvement de l’interface HS/BS. Les résultats obtenus sont très encourageants et reproduisent avec une grande fidélité les données expérimentales. Cependant l’origine de l’orientation de l’interface HS/BS observée par microscopie optique dans les cristaux du composé [{Fe(NCSe)(py)2}2(m-bpypz)] était restée mystérieuse. Pour résoudre cette question, nous avons développé un modèle électro-élastique qui tient compte du changement de volume au cours de la transition de spin. Ce dernier nous a conduits à analyser l’effet de la symétrie du réseau cristallin et de la forme du cristal sur l’orientation de l’interface élastique. En l’appliquant au composé [{Fe(NCSe)(py)2}2(m-bpypz)], en tenant compte du caractère anisotrope du changement de la maille élémentaire lors du passage HSBS, nous avons réussi à retrouver quantitativement l’orientation du front observée expérimentalement en microscopie optique. Ceci confirme bien le rôle primordial de l’élasticité dans le comportement des matériaux à transition de spin. Des études sous lumière à très basse température nous ont donné la possibilité de suivre en temps réel, l’effet LIESST (Light Induced Excited Spin State Trapping), la re-laxation coopérative du cristal ainsi que l’instabilité photo-induite LITH (Light Induced Thermal Hysteresis). Un monde fascinant est apparu autour de cette dernière, avec la présence de comportements totalement inédits. Ainsi, et pour la première fois, nous avons mis en évidence l’existence de phénomènes d’auto-organisation et de comportements autocatalytiques du front de transition. Cette physique non-linéaire dénote un comportement actif du cristal, par suite d’une subtile préparation autour d’un état instable. Ces comportements rappellent les structures dissipatives de Turing et ouvrent des perspectives fascinantes pour cette thématique, tant sur le plan expérimental que théorique. / This thesis work is devoted to visualization by optical microscopy of thermo- and photo-induced phase transitions, in switchable spin transition single crystals. The study of crystals of the compound [{Fe (NCSe) (py) 2} 2 (m-bpypz)] showed the possibility to control reversibly the dynamics of the HS/LS interface through a photo-thermal effect generated by an irradiation of the whole crystal or using a spatially localized light spot on the crystal surface. The investigations of the effect of the light intensity on the transition temperature have highlighted the importance of the coupling between the crystal and the thermal bath in these experiments. Concomitantly, we developped a reaction diffusion model allowing to describe and iden-tify the relevant physical parameters involved in the control of the movement of HS/LS interface. The obtained results are very encouraging and reproduce the main features of the experimental data. However the origin of the interface orientation observed by the optical microscopy in the crystal of the compound [{Fe (NCSe) (py) 2} 2 (m-bpypz)] re-mained mysterious, and needed an elastic approach to be handled. At this end, an electro-elastic model including the volume change at the spin transition was developed. By taking into account for the anisotropy of the unit cell deformation at the transition, we were able to reproduce quantitatively the experimental HS/LS interface orientation. This result confirms the crucial role of the lattice symmetry and its elastic properties in the emergence of a stable interface orientation. The last part of the thesis is devoted to the investigation of photo-induced effects at very low temperatures (~10K). There, we visualized for the first time the real time transformation of a single crystal under LIESST (Light Induced Excited Spin State Trapping) effect as well as its subsequent relaxation at higher temperatures. We have also studied the light induced instabilities through investigation on the LITH (Light Induced Thermal Hysteresis) loops. Around the latter, a fascinating world made of nonlinear effects, and patterns formation emerged, recalled the well known Turing structures. These results lead to new horizons that will give access to new theories and original experimental observations that will enrich the topics opening the new avenues to study of nonlinear phenomena in spin crossover solids.

Titre : La compensation écologique : du principe de non perte nette de biodiversité à son opérationnalisation – analyse de l’action collectiveMots clés : Compensation écologique, action collective, effets spatio-temporels, Non perte nette de biodiversité.Résumé : En France la compensation écologique des impacts résiduels sur la biodiversité a pour objectif l'atteinte de la non perte nette de biodiversité. Un cadre normatif énonçant une dizaine de principes permet théoriquement d'atteindre cet objectif.Nous étudions donc la mise en œuvre de la compensation écologique à travers trois projets de LGV. Nous analysons le jeu d'acteur autour de cette mise en œuvre grâce aux théories de l'action collective, et notamment grâce au cadre analytique de la Traduction proposé par M. Callon. Cette première analyse nous permet de comprendre en quoi la compensation est un objet socio-technique. Nous mettons en évidence que de nombreux acteurs aux intérêts divergents se mobilisent pour mettre en place la compensation écologique. Nous montrons qu’il y a une tension entre la mobilisation des acteurs et les exigences écologiques, ces deux aspects ne sont pas toujours compatibles. La durée des cahiers de charges et la rétribution des propriétaires fonciers, chargés de la mise en œuvre de la compensation écologique est déterminante à la fois pour la mobilisation des humains et des nons humains (biodiversité). Nous nous interrogeons ensuite sur les effets spatiaux temporels de l’action collective et de sa capacité à tendre vers une non perte nette de biodiversité. Nous montrons que les mesures n’ont pas pu être effectives avant le démarrage des impacts. La gestion du foncier en France semble pour le moment difficilement compatible avec une mise en œuvre de la compensation non anticipée très en amont. Nous montrons que la majorité des sites de mesures de compensation sont de petites tailles, bien que des espaces de grandes tailles semblent davantage vertueux d’un point de vue écologique. Enfin nous montrons que la pérennité des mesures de compensations peut être appréhendée à différents niveaux suivant (i) le type de maîtrise foncière (acquisition, conventionnement); (ii) les contrats de mesures de compensation (durée, contenu de ces derniers – les sanctions en cas de manquement aux obligations influent sur le maintien des mesures) ; (iii) la gestion du renouvellement de ces contrats; (iv) la vocation des propriétaires des sites (une entreprises publique ou privée de construction n’a pas comme rôle au départ de conserver la biodiversité, tandis qu’une association naturaliste en a la vocation) ; (v) la pérennité des structures et les assurances quant au devenir des sites de mesures de compensation en cas de faillite; (vi) le suivi et le contrôle l’application de la compensation. / In France, the objective of ecological compensation for residual impacts on biodiversity is to achieve no net loss of biodiversity. A normative framework setting out about ten principles theoretically makes it possible to achieve this objective.We are therefore studying the implementation of biodiversity offset through three High Speed Railway projects. We analyze the actor's game around this implementation through the theories of collective action, and in particular the analytical framework of Translation proposed by M. Callon. This first analysis allows us to understand how biodiversity offset is a socio-technical object. We highlight that many actors with diverging stakes are mobilizing to implement ecological compensation. We show that there is a tension between the mobilization of actors and ecological requirements, these two aspects are not always compatible. The duration of the environmental services specifications and the associated retribution of landowners, who set-up biodiversity offset specification, is decisive for both human and non-human (biodiversity) mobilization. We then question the temporal spatial effects of collective action and its ability to achieve a net loss of biodiversity. We show that the measures could not be effective before the impacts began. Land management in France seems for the moment to be difficult to reconcile with the implementation of unanticipated biodiversity offset at a very early stage. We show that the majority of biodiversity offset sites are small in size, although larger areas seem more virtuous for biodiversity. Finally, we show that the sustainability of biodiversity offset measures can be assessed at different levels depending on (i) the type of land control (acquisition, agreement); (ii) biodiversity offset contracts (duration, content of the latter - sanctions in the event of failure to comply with obligations influence the maintenance of the measures); (iii) the management of the renewal of these contracts; (iv) the vocation of the owners of the sites (a public or private construction company does not initially have the role of conserving biodiversity, whereas an environmental NGO has the vocation); (v) the sustainability of the structures and assurances as to the future of the biodiversity offset measures sites in the event of bankruptcy; (vi) the monitoring and control of the implementation.

La question prioritaire de constitutionnalité (QPC), instaurée en 2008, permet au Conseil constitutionnel de se prononcer sur la conformité d’une disposition législative déjà entrée en vigueur, aux « droits et libertés que la Constitution garantit ». Les effets substantiels des décisions QPC, c'est-à-dire la suppression ou la modification d’une disposition législative par le prononcé d’une inconstitutionnalité ou d’une réserve d’interprétation, peuvent se révéler importants compte tenu de la portée erga omnes de ces décisions. C’est alors par la maîtrise de leur application temporelle que les effets substantiels vont être encadrés voire modérés. Certains effets temporels revêtent un caractère automatique : la décision QPC en tant qu’elle porte sur une norme (la disposition législative en cause), s’insère dans l’ordonnancement juridique et, à ce titre, génère des conflits de normes. Par ailleurs, les effets temporels peuvent également, et surtout, être choisis par le Conseil constitutionnel, par l’utilisation de son pouvoir de modulation. Ce pouvoir a été conçu de manière à laisser une grande liberté au Conseil constitutionnel. Dans une démarche d’efficacité, le juge constitutionnel s’est fixé l’objectif de faire bénéficier le justiciable d’un« effet utile » de ses décisions et a par conséquent valorisé l’usage de la rétroactivité. Cependant, la liberté seule n’assure pas une pleine maîtrise de ce pouvoir de modulation et ce même pouvoir est parfois insuffisant pour régir les effets substantiels des décisions QPC. La thèse contribue, sur la base d’une analyse exhaustive de l’ensemble des décisions QPC du Conseil et de trèsnombreuses décisions dites « retour de QPC » des juridictions ordinaires, à étudier ces insuffisances et notamment le manque de réflexion sur la compatibilité entre la technique de la modulation et l’office du juge constitutionnel et sur la nécessité d’une collaboration avec les juridictions ordinaires. / The priority question of constitutionality (QPC), created in 2008, allows the french Constitutional Council to operate a judicial review of an adopted law. The substantial effects of a QPC decision, ie the abolition or the modification of a legislation by pronouncing its unconstitutionality or by interpreting it in accordance with the Constitution, can be considerable given the erga omnes impact of these decisions. These substantial effects can however be controlled or moderated by the temporal effects. Some temporal effects are inevitable: the QPCdecision since it concerns a norm (the law), integrates with the legal order and generates norms’ conflicts. Otherwise the temporal effects can be chosen by the Constitutional Council thanks to the ability of modulating the temporal effects of its decisions. This jurisdictional technical lets total liberty to the Constitutional Council. The court, in an efficacy perspective, sets the objectiveof giving a « useful effect » to the litigant and thus accords value to retroactivity. Yet this liberty alone isn’t enough to provide a complete control of this modulating ability and this ability can’t regulate all the substantial effects. This thesis, based on an exhaustive jurisprudential analysis ofthe QPC decisions, aims to study these difficulties and especially the lack of reflection about the compatibility of the technical into the judicial office of the court and about the essential collaboration with the ordinary jurisdictions.