Learning about time was part of the indoctrination of Christians in the late antique West. Time played an important role in Scripture and also in the pagan milieu from which most catechumens came. Thus, bishops were required to explain to their flocks traditional Christian concepts of time, while at the same time refute unacceptable ideas concerning time (i.e., astrology, pagan festivities), which were normally an ingrained part of the late Roman mind-set. The sermon was the predominant means of communicating these ideas. Chapters one and two begin by establishing the boundaries of time (Creation and eschatology). Bishops attempted to link all time to Christ by demonstrating that time-units had their origin in Creation and their consummation in the dies iudicii. This belief in Christ's mastery over time proved advantageous in anti-pagan and anti-heretical polemic. Chapters three through five examine the time-units themselves (e.g., the year, month, seasons, week, day and night). Symbolic exegesis and technical explanations of the workings of time-units were used to fortify the belief that all time comes from God, which, in turn furthered the demythologization of sun, moon, and stars. Chapter six examines episcopal prescriptions as to how lay Christian should spend their day-to-day life. As a general rule, bishops promoted the devotion of all time to God, requiring, at least as an ideal, that their flocks live like ascetics. This included frequent fasting and almsgiving and daily public and private worship. Chapters seven and eight follow episcopal attempts to enlarge their calendars with festivals, thus increasing the special periods of time during which the laity would be fixated on God.

This thesis seeks to demonstrate the Apocalypse of Paul's position within the broader Valentinian literary corpus from the Nag Hammadi codices. Previous scholars, notably William Murdock and Michael Kaler, have gestured in this direction, but no attempt has been made to systematically situate the Apocalypse of Paul in relation to other Valentinian sources. Quite possibly this desideratum exists because although the Apocalypse of Paul's debt to Jewish apocalypticism is self-evident, scholars of Valentinianism have generally neglected those ideas in Valentinian literature which are derived ultimately from Judaism, often received via Paul or other New Testament writers. These would include the notion of the Name of God as a saving power, even a soteriological agent, and the image of a surrogate heavenly temple through which favoured adepts may ascend in the present. These come to be combined in Valentinian thought through a high-priestly Christology in which it is by virtue of bearing the Divine Name that one may enter this ideal temple in the fashion of the old Jewish high priest, and now Christ. On the other hand, Valentinians downgrade the biblical creator-God to the level of an imperfect demiurge, placing him in an inferior heavenly temple while supplanting the Pleroma atop him as the true spiritual temple housing the Father of Christ. The development of this constellation of ideas is traced principally from Valentinus himself, through the Gospel of Truth and the Excerpts from Theodotus, to the Gospel of Philip, where it receives its most extensive explication. It is argued that the Apocalypse of Paul consciously builds on this intellectual current using the apostle's image in order to construct an ideal authoritative account of how such ascent ought to appear among Valentinian initiates and thereby contribute to the rhetorical and psychological construction of future experiences among the elect community.

abstract: Seismic observations have revealed two large low shear velocity provinces (LLSVPs) in the lowermost mantle beneath Pacific and Africa. One hypothesis for the origin of LLSVPs is that they are caused by accumulation of subducted oceanic crust on the core-mantle boundary (CMB). Here, I perform high resolution geodynamical calculations to test this hypothesis. The result shows that it is difficult for a thin (~ 6 km) subducted oceanic crust to accumulate on the CMB, and the major part of it is viscously stirred into the surrounding mantle. Another hypothesis for the origin of LLSVPs is that they are caused by thermochemical piles of more-primitive material which is remnant of Earth's early differentiation. In such case, a significant part of the subducted oceanic crust would enter the more-primitive reservoir, while other parts are either directly entrained into mantle plumes forming on top of the more-primitive reservoir or stirred into the background mantle. As a result, mantle plumes entrain a variable combination of compositional components including more-primitive material, old oceanic crust which first enters the more-primitive reservoir and is later entrained into mantle plumes with the more-primitive material, young oceanic crust which is directly entrained into mantle plumes without contacting the more-primitive reservoir, and depleted background mantle material. The result reconciles geochemical observation of multiple compositional components and varying ages of oceanic crust in the source of ocean-island basalts. Seismic studies have detected ultra-low velocity zones (ULVZs) in some localized regions on the CMB. Here, I present 3D thermochemical calculations to show that the distribution of ULVZs provides important information about their origin. ULVZs with a distinct composition tend to be located at the edges of LLSVPs, while ULVZs solely caused by partial melting tend to be located inboard from the edges of LLSVPs. This indicates that ULVZs at the edges of LLSVPs are best explained by distinct compositional heterogeneity, while ULVZs located insider of LLSVPs are better explained by partial melting. The results provide additional constraints for the origin of ULVZs. / Dissertation/Thesis / Doctoral Dissertation Geological Sciences 2015

O saco vitelino é a principal fonte de nutrição do embrião durante o período em que a placenta verdadeira ainda não está completamente formada. É responsável pela hematopoiese, pois dele se desenvolvem os primórdios das células sanguíneas, bem como parte do sistema circulatório primitivo do embrião. Tivemos como objetivo caracterizar a área transicional do saco vitelino para o intestino primitivo através de análise macroscópica, microscopia de luz, microscopia eletrônica de transmissão e reação imunohistoquímica para detecção de células germinativas (Oct-4). Foram realizados cortes seqüenciais de todos os embriões para permitir a visualização da estrutura como um todo. Nas amostras obtidas, pudemos observar a presença do saco vitelino com a área de conexão com intestino primitivo composto por inúmeras ilhotas vasculares que correspondem aos vasos envolvidos pelas células vitelínicas e células mesenquimais. No interior dos vasos identificamos hemangioblastos em grande quantidade. A camada correspondente ao mesênquima é delgada e com células alongadas e endoderma da membrana vitelínica é composto por células endodérmicas, grandes, uni ou binucleadas. Tal arranjo celular se assemelha a uma glândula devido a sua arquitetura em ilhas vasculares somado às camadas teciduais. O epitélio do intestino primitivo inicia sua diferenciação com células colunares estratificadas e bordadura em escova seguido de células mesenquimais indiferenciadas. A área transicional entre o saco vitelínico e o intestino primitivo é estreita em relação à luz destas duas estruturas com células de formato irregular, constituindo um delicado revestimento no lúmen contendo hemangioblastos. No mesênquima da área transicional inúmeros e pequenos capilares foram observados com hemangioblastos em seu interior. Em embriões e fetos submetidos à imunohistoquímica, verificamos células reativas como o metanefro, gônadas, parênquima hepático e saco vitelino. / The yolk sac is the main source of embryo nutrition during the period that true placenta are not still formed and responsible by hematopoieses because from it were developed the blood cells, as a part of embryo primitive circulatory system. We aimed to characterize the transitional area between the yolk sac and the primitive intestine by light microscopy, transmission electron microscopy and detection of germ cell lines by Oct-4 immunohistochemistry. Were done in all embryos serial sections to permit the identification for all structures. Were possible identify the yolk sac connection with primitive intestine composed by many blood islet corresponding to relation with yolk and mesenchymals cells. Inside the vessels were identified hemangioblasts. The layer corresponding to mesenchyme is thin and with elongated cells and the vitellinic membrane endoderm is composed by large, uni or binucleate endodermic cells. This shape is similar to a gland related to their architecture, vessels islets and tissue layers. Primitive intestine epithelium begins their differentiation with stratified columnar cells and undifferentiated mesenchymals cells. This transitional area is thin related to their lumen with irregular shape and constituted by delicate lumen basement and hemangioblast. Inside the mesenchyme there are many smaller capillaries observed with hemangioblast in it. Embryos and fetus submitted to immunohistochemistry and were verified positive cells like metanefrons, gonads, hepatic parenchyma and yolk sac.

O desenvolvimento de biotecnologia de embriões em animais de produção é prejudicado por perdas no primeiro trimestre da gestação, idade em que o intestino primitivo está sendo estabelecido. O estudo das proteínas contidas no intestino primitivo nesta fase inicial da gestação pode aumentar o conhecimento sobre as vias moleculares envolvidas no desenvolvimento embrionário normal e em perdas de embriões, assim como a sua participação na organogênese e diferenciação celular. Intestino primitivo de embriões de bovinos a partir dos 39 SD ± 4 dias de desenvolvimento (variando de 33 a 45 dias) foram coletados em um matadouro local. As amostras foram processadas e agrupadas para análise proteômica shotgun label-free usando MudPIT (Multidimensional Protein Identification Technology). Análise funcional e de via foram feitas usando FatiGO (www.babelomics.org); Pathway Express (http://vortex.cs.wayne.edu/ ontoexpress) para identificar as ontologias relevantes e vias canônicas ou não-canônicas representada pelas proteínas expressas no Intestino primitivo. Um total de 74 proteínas ou sequências randômicas foram identificadas, correspondentes a 30 proteínas específicas expressas pelo Intestino primitivo bovino. Das 30 proteínas únicas, 21 proteínas foram utilizadas na ontologia e análise de vias. As análises mostraram um enriquecimento de ontologias relacionadas com a ligação (N = 5); atividade catalítica (N = 6); organela intracelular (N = 6). Houve um enriquecimento de ontologias associado às modificações do citoesqueleto; processo de diferenciação celular (N = 3), a migração celular (N = 4) e no metabolismo celular (N = 6). Além disso, a via e a análise de rede mostraram um enriquecimento de vias de comunicação entre células, tais como junções comunicantes e tight e as vias de adesão focal. Além disso, as vias envolvidas no movimento celular (por exemplo, vias de regulação do citoesqueleto de actina e a migração transendotelial de leucócitos) foram extremamente enriquecimento no grupo de proteínas expressas pelo Intestino primitivo bovino. Nossos resultados sugerem que as células do intestino primitivo tem alto perfil migratório e são compostas de células não totalmente diferenciadas, com alto metabolismo celular. A migração e a diferenciação destas células poderiam determinar o destino do embrião em desenvolvimento. Além disso, a compreensão da função e interação de proteínas expressas pelo embrião normal fornecerá informações sobre o impacto das biotecnologias reprodutivas no desenvolvimento do embrião durante a implantação e placentação. / The development of embryo biotechnology in farm animals is hampered by embryo losses in first trimester of gestation, period in which the primitive gut is being established. The study of proteins contained in the primitive gut at this early stage of pregnancy may increase the knowledge about the molecular pathways involved in normal embryonic development and loss of embryos, as well as their involvement in organogenesis and cell differentiation.primitive gut from bovine embryos on day 39 SD± 4 of development (ranging from 33 to 45 days) were collected at a local slaugtherhouse. The samples were processed and pooled for label-free shotgun proteomics analysis using MudPIT (Multidimensional Protein Identification Technology) tandem MSE acquisition. Functional and pathway analysis using FatiGo (www.babelomics.org); Pathway Express (http://vortex.cs.wayne.edu/ ontoexpress) and Ingenuity Pathway Analysis (www.ingenuity.com) were used to identify relevant ontologies and canonical or noncanonical pathways represented by the expressed proteins in the primitive gut. A total of 74 protein sequences were identified corresponding to 30 unique proteins expressed by the bovine primitive gut. out of 30 unique proteins, 21 proteins were used on the ontology and pathway analysis. The ontology analysis showed an enrichment of ontologies related to binding (N=5); catalytic activity (N=6); intracellular organelle (N=6). There was an enrichment of ontologies associated to cytoskeleton modifications; cell differentiation process (N=3); cellular migration (N=4) and cell metabolism (N=6). Furthermore, the pathway and the network analysis showed an enrichment of cell-to-cell communication pathways such as gap and tight junction, and focal adhesion pathways. In addition, pathways involved in cellular movement (regulation of actin cytoskeleton and leukocyte transendothelial migration) were extremely enrichment in the group of proteins expressed by the bovine primitive gut. Our results suggested that the cells from primitive gut have high migratory profile and are composed of not fully differentiated cells with high cellular metabolism. The proper migration and differentiation of these cells would dictate the fate of the developing embryo. Moreover, understanding the function and interaction of proteins expressed by normal embryo will give clues of the impact of the reproductive biotechnologies in embryo development during the window between implantation and placentation.

The following thesis explores the social identities of TertuIIian, a Christian from Carthage who lived from approximately 160 to 220. After exploring the implications of calling TertuIIian an "African Theologian," the introduction interacts with the work done on TertuIIian in the past, concluding that although he was once read Euro-centrically and assumed to be a Roman, explicitly, and a European, implicitly, scholars in recent decades have deconstructed the biographical information of TertuIIian, leaving his African origin as one of the only undisputed aspects of his life. However, while scholars have located TertuIIian within the broader movements of the Roman Empire, few have explored the North African milieu in relation to Tertullian's writings. In order to contribute to this area of scholarship, theories from the discipline of Social Anthropology are accommodated and applied to selections of Tertullian's writings, thereby exploring Tertullian's construction of his own identities. The social theories applied, namely, social identity, kinship identity, class identity, ethnic identity and religious identity, are used heuristically to read the sources from Roman Africa in order to inquire as to the various identities constructed by individuals and groups. Within the social context of Roman Africa, this study establishes the categories of Roman colonizers, indigenous Africans and new elites. The third category, new elites, is actually meant to destabilize the other two, denying any "essential" Roman or African identity. Once the context has been framed, the thesis investigates samples from Tertullian's writings to compare his construction of his own identities and the identities of his rhetorical opponents. In order to interpret Tertullian's social identities, one chapter compares the identities Tertullian constructs in his works Apologeticum and Ad nationes. The similarity of these two tracts allows for an inquiry into TertuIIian's "Other" and the "Other" Tertullian constructs for his audiences. The subsequent chapter applies kinship theory in order to compare Tertullian's ideals with those of Roman kinship and early Christian kinship. Therein, the usual discussion of Tertullian's view of marriage is readdressed by comparing the kinship identities and ideals forwarded in his works Ad uxorem 1 and 2. Closely connected to Tertullian's kinship identity is that of his class identity, and, while his exact status and class may be elusive in historical terms, one can explore his socio-economic ingroup and outgroup as he portrays them in De cultu feminarum 1 and 2. Tertullian's ethnic identity is discussed in a chapter that interprets his works De uirginibus uelandis and De pallio, in which it is suggested that Tertullian establishes boundaries between his own ethnic group and that of Roman colonizers. The last form of identity discussed, religious identity, involves a reinterpretation of TertuIIian's use of the New Prophecy. Therein, Tertullian's religious "Other" is understood to be constructed with not only "psychic" rhetoric, but also with Roman imagery. The overall study finds Tertullian's identities to be manifold, complex and discursive. Additionally, his writings are understood to reflect antagonism towards Romans, including Christian Romans, and Romanized Africans. While TertuIIian accommodates much from (Graeco-)Roman literature, laws and customs, he nevertheless retains a strongly stated non-Roman-ness and an African-ity which have been almost entirely neglected in past studies, and it is this aspect, therefore, which is highlighted in the present thesis.

L’histoire et la sociologie critique de l’urbanisme se sont construites, depuis les années 1960, en dénonçant le caractère technocratique d’une discipline qui substitue sa normativité à l’urbanité de la ville traditionnelle. Paradoxalement, elles ont contribué à couper les racines descriptives que l’urbanisme a puisées dans le champ des sciences sociales naissantes au début du XXe siècle. Le savoir territorial que les premiers urbanistes cultivent avec la géographie et l’histoire sociale sont réduites à l’influence épistémologique du positivisme scientifique d’Auguste Comte et du matérialisme historique de Karl Marx et Fridriech Engels. Dès lors, l’histoire critique de l’urbanisme moderne se construit suivant l’hypothèse d’une rupture spatio-temporelle avec le présent - l’utopie - et de la réduction de l’empirisme à des lois normatives. Les projets théoriques des grandes figures de son histoire - Camillo Sitte, Ebenezer Howard, Tony Garnier, Le Corbusier, Walter Gropuis, Frank Loyd Wright et Ludwig Hilberseimer - sont envisagés comme autant de témoignages de ce projet utopique et positiviste qui aurait été repris dans ses grandes lignes par une génération de professionnels qui imposent les lois de l’urbanisme moderne jusqu’aux années 1960. Cette thèse se veut un questionnement fondamental sur le rapport entre l’urbanisme naissant et l’histoire sociale et économique et la géographie humaine dans la première moitié du XXe siècle en Belgique. En retraçant l’exploration parcourue par les premiers urbanistes belges de cette « grande génération » autour des notions de « ville tentaculaire », de « société rurale primitive », d’ « agglomération rurale », de « ville marchande des Pays-Bas méridionaux », de « région industrielle » et de « ville fonctionnelle », elle entend (re)découvrir les référents culturels et empiriques que ceux-ci vont partager avec le champ des sciences sociales naissantes en Belgique. En invoquant la pensée des socialistes Emile Vandervelde et Henri De Man, du sociologue Ernest Mahaim, des historiens Henri Pirenne et Guillaume Des Marez, de l’ingénieur Alexandre Delmer, de l’économiste Paul Michotte et du géographe Omer Tulippe, qui vont tous contribuer à forger les particularités d’une culture sociale, économique et géographique propre au territoire de la Belgique dans la première moitié du XXe siècle, la thèse veut réhabiliter les subtilités d’un réseau d’échanges transdisciplinaires que l’histoire de l’urbanisme moderne a négligé. Elle cherche également préciser le rapport que la discipline naissante entretient avec la rationalité moderne et en particulier le taylorisme.La thèse entend montrer le questionnement fondamental sur les formes socio-spatiales de la modernité que ces protagonistes vont initier en se nourrissant de l’histoire et de la géographie. Pour ce faire, cette étude focalise sur les liens entre les sciences sociales naissantes et les réflexions des acteurs de la Société des Urbanistes Belges (SUB, 1919-1970), de l’Institut d’Urbanisme de l’Institut Supérieur des Arts Décoratifs - La Cambre (1928-1979) et du Groupe L’Equerre (1935’-) dont la découverte de certains documents originaux permet de comprendre la richesse d’une réflexion empirique profondément inscrite dans le territoire et l’histoire de la Belgique .De cette manière, la thèse entend révéler les particularités épistémologiques et conceptuelles que les premiers urbanistes belges vont construire en ancrant les notions de « ville tentaculaire », d’« agglomération » et de « région industrielle » dans une culture territoriale qui est nourrie par l’expérience quotidienne et l’empirie des sciences sociales. La thèse se penche en particulier sur quatre urbanistes qui vont initier des liens directs avec les sciences sociales - Raphaël Verwilghen avec l’étude du peuplement, Jean De Ligne avec l’histoire sociale et économique, Jean-Jules Eggericx avec le taylorisme et Emile Parent avec la géographie humaine. Dans le prolongement de ces travaux théoriques fondateurs, cette étude s’intéresse aux liens entre ces protagonistes et d’autres urbanistes qui vont utiliser les référents culturels véhiculés par ces sciences sociales dans des projets urbanistiques: - l’ « agglomération rurale » de Raymond Moenaert, la « ville sporadique » de Louis Van der Swaelmen, la « ville tentaculaire » de Raphaël Verwilghen puis l’ « agglomération industrielle » de Jean De Ligne et Maurice Heymans et la « région industrielle » de Gustave Herbosch, d’Emile Parent et du Groupe L’Equerre.À la différence des travaux monographiques existants d’histoire de l’urbanisme en Belgique, qui se sont plutôt focalisés sur la réception de modèles dominant la discipline dans d’autres nations européennes dans la première moitié du XXe siècle - le tracé de ville monumentale des métropoles, la déconcentration en cités-jardins, les villes denses bâties en hauteur des années 1930 et les cités industrielles linéaires des années 1940 et 1950 - cette thèse cherche à identifier les référents culturels qui ancrent la pratique urbanistique dans une étude empirique et historique du territoire de la Belgique que les sciences sociales naissantes contribuent à façonner.En révélant l’enracinement de la culture urbanistique des protagonistes de la SUB et de l’Institut d’Urbanisme de l’ISAD La Cambre dans la « ville tentaculaire » de Verhaeren et Vandervelde, le portus du Moyen-Age de Pirenne et Des Marez, L’idée socialiste de De Man, la « région industrielle » de Delmer, Michotte et Tulippe, cette thèse veut montrer qu’il ne s’agit ni de la « métropole monumentale radioconcentrique », ni de la « déconcentration en cités-jardins », ni de la « ville concentrée bâtie en hauteur », ni de la « ville linéaire socialiste » mais d’un lieu d’échange économique aggloméré dans le bas de la vallée au carrefour des voies de transport inscrites dans l’oro-hydrographie et, dans le prolongement duquel on conçoit l’industrie et, dispersés sur les versants, l’habitat et les communautés.Ce modèle qui se dégage progressivement de la réflexion des premiers urbanistes belges, au détour d’une longue gestation, ne peut être appréhendé que si l’on étudie l’expérience de ces intellectuels belges de manière globale et contextualisée, en ouvrant les limites du champ de l’histoire de l’urbanisme à l’empirie des sciences sociales naissantes et en se démarquant de l’approche mono-biographique qui a dominé le champ de l’histoire de l’architecture et de l’urbanisme. La figure socialiste-libérale de l’agglomération marchande et industrielle n’apparaîtra que si l’on relativise l’histoire critique de l’urbanisme occidental et, en particulier, les idées de rupture socio-spatiale et de réductionnisme scientifique, pour explorer les particularités de l’histoire sociale et économique du territoire des anciens Pays-Bas méridionaux, qui inspire la pensée urbanistique en Belgique jusque dans les années 1960.Pour comprendre ce règne de l’empirie et du particularisme du milieu, il faudra d’abord admettre que Verhaeren est autant un géographe qu’un poète, que Vandervelde cherche à voir bien au-delà du « retour au champ ». Il faudra mettre de côté L’histoire de la Belgique d’Henri Pirenne et Le Plan du Travail de De Man pour redécouvrir les œuvres de jeunesse de ces auteurs. Il faudra relativiser l’Arrêté-Loi sur l’urbanisme de 1915, les cités-jardins des années 1920, les premières villes denses bâties en hauteur de Le Corbusier et Victor Bourgeois et les villes linéaires de Renaat Braem. On pourra alors redécouvrir la richesse d’une culture socio-spatiale moderne spécifique au territoire de la Belgique que l’institutionnalisation de l’aménagement du territoire a réduit au zonage des plans de secteurs et qui, dans la période de désindustrialisation et de crise environnementale que nous connaissons aujourd’hui, pourrait nous aider à penser le territoire au delà des dichotomies urbain - rural et réconcilier la ville avec l’économie et l’environnement sans tomber dans les travers d’un néolibéralisme débridé ou d’un interventionnisme d’état démesuré. / Doctorat en Art de bâtir et urbanisme (Architecture) / info:eu-repo/semantics/nonPublished

Cette thèse porte sur l'étude des atmosphères de Titan et de la Terre primitive avec des modèles de circulation générale (GCM). Tout d'abord, j'ai analysé la structure thermique et la dynamique de la basse troposphère de Titan. Cette étude a abouti à une caractérisation complète de la couche limite et a révélé l'existence d'une circulation de couche limite, qui impacte tous les aspects de la météorologie titanienne (régimes de vents, ondes, formation des dunes et des nuages, échanges de moment cinétique et superrotation). A partir de cette analyse, j'ai proposé une nouvelle hypothèse pour expliquer l'orientation vers l'est des dunes de Titan grâce à un couplage entre les orages tropicaux et la superrotation. Ceci a été validé par des simulations méso-échelles et a permis de proposer un schéma global expliquant la formation des dunes et leurs différentes caractéristiques. J'ai ensuite participé au développement d'un GCM générique, conçu pour étudier tout type d'atmosphère. Je l'ai appliqué aux paléoclimats de Titan pour simuler une période où l'atmosphère a pu être dépourvue de méthane. Dans ce cas, le climat devait être différent d'aujourd'hui avec potentiellement des conséquences géologiques fondamentales notamment pour l'érosion et l'âge de la surface. Finalement, j'ai appliqué ce GCM générique au cas de la Terre primitive. J'ai montré que, malgré un soleil moins lumineux qu'aujourd'hui et des quantités de gaz à effet de serre contraintes par les archives minéralogiques, le climat de la Terre Archéenne a pu être tempérée. En particulier, grâce à une rétro-action nuageuse, la Terre aurait pu éviter une glaciation globale et rester propice au développement de la vie. / This thesis focuses on the study of the atmospheres of Titan and the early Earth with Global Climate Models (GCM). First, I analysed the thermal structure and the dynamics of Titan's lower troposphere. This analysis allowed a full caracterization of the planetary boundary layer and revealed the existence of a boundary layer circulation which impacts every aspect of Titan's weather (wind patterns, atmospheric waves, dune and cloud formation, exchange of momentum with the surface, and development of the superrotation). Thanks to this study, I proposed a new hypothesis to explain the eastward orientation of Titan's dunes that implies a coupling between tropical storms and the superrotation. This has been validated with mesoscale simulations and provided a general framework to explain Titan's dune formation and features. Then, I participated to the development of a generic GCM, designed to study any kind of atmosphere. I applied it to Titan's paleoclimates, when the atmosphere was depleted of methane. In such a case, the climate should have been different from today, with potentially fundamental geological consequences, in particular for the erosion and the age of the surface. Finally, I applied this GCM to the case of the early Earth using greenhouse gas abundances constrained by mineralogical data. I showed that despite a weaker solar insolation, the Archean Earth's climate may have been temperate. In particular, the Earth may have avoided a full glaciation and remained suitable for the development of life thanks to cloud feedback, even assuming a amount of CO2 just a little larger than today.

This study explores how Anglophone fiction from the mid-Victorian period to the outbreak of the First World War acted as an imaginative testing-ground for theories of the evolution of language. Debates about the past development and the future of language ranged beyond the scope of empirical data and into speculative narrative. Fiction offered to realize such narratives in detail, building imaginative worlds out of different theories of language evolution. In the process, it also often tested these theories, exposing their contradictions. The lack of clear boundaries between nature and culture in language studies of the period enabled fictions of language evolution to explore questions to which contemporary researchers have returned. To what extent is communication instinctive or conventional? How do social and biological factors interact in the production of meaning? The study traces two opposing tendencies of thought on language evolution, naming them language ‘progressivism’ and ‘vitalism’. Progressivism imagined speakers evolving away from involuntary, instinctive vocalizations to extert rational control over their discourse with mechanical precision. By contrast, language vitalism posited a mysterious, natural power in words which had weakened and fragmented with the rise of writing and industrial society. Certain genres of fiction lent themselves to exploration of these ideas, with utopian tales seeking to envision the end-goals of progressive theory. Representations of primitive language in imperial and prehistoric romances also promoted progressivism by depicting the instinctive, irrational speech from which ‘civilization’ was imagined as advancing away. Conversely, much historical and invasion fiction idealized a linguistic past when speech had expressed natural truth, and the authentic folk origins of its speakers. Both progressivism and vitalism were undermined through the late nineteenth century by developments in biology, which challenged claims of underlying stability in nature or purpose in change. Simultaneously, philologists increasingly argued that meaning was conventional, attacking models of semantic progress and degradation. In this context, a number of authors reconceptualized language in their fiction as a mixture of instinct and convention. These imaginative explorations of the borderlands between the social and biological in communication prefigured many of the concerns of twenty-first-century biosemiotics.

This investigation is in the discipline of theology (Church History) and seeks to discover how and why the early Christians separated themselves from the world in which they lived, and the results thereof. A study is made of the Roman Empire of the first three centuries, its politics, commerce and industry, and entertainment. The Christians’ separateness-policy under these three headings is then examined in some detail. They lived and worked among the people of the empire, but were separate from them in their code of conduct. The Christians’ separateness in politics was expressed by their refusal to worship the state gods and participate in the ceremonies, festivals and sacrifices associated therewith. They were ‘atheists’ who brought down the wrath of the gods upon the land. They followed a non-violence policy and preferred not to join the army and were viewed as disloyal subjects. People of all class-distinctions were welcomed at their gatherings and this was seen as a challenge to Roman sovereignty and the established class-order. The Christians’ separateness in commerce and industry was expressed in their refusal to join the guilds and to make sacrifices to the gods. They would not take jobs that promoted immorality or idolatry or that devalued human life. Their allegiance was to Christ and not to human patrons, and they supported one another financially within the Christian fellowship. The Christians’ expressed their separateness in leisure and entertainment by refusing to attend the games and spectacles of the arena and would not take part in the sacrifices associated with them. They spoke against gambling and the activities of the theatre, and followed a new style of sexual conduct that taught modesty, purity, and the sanctity of marriage. Rather than take part in meals that encouraged drinking and immorality, they met for simple Love Feasts. Many Christians died cruel deaths in these arenas. In spite of the opposition, Christianity continued to grow and by the end of the third century was a ‘state within a state’, independent and able to take care of her own. The last great persecution took place between AD 303-313 when severe and cruel ultimatums were issued to the Christians. Eventually the pagan world was convinced that if Christianity was worth dying for then it was worth living for. Many believed that their own gods had failed them. In AD 313, emperor Constantine proclaimed Christianity to be legal, and not long afterwards Christianity was proclaimed the state religion. Some hundred years later, it was the empire that ended, not Christianity. A comparison can therefore be made of the separateness of the early church who believed Christ’s words stating that they were ‘in the world but not of the world’, and today’s contemporary Christian and Pentecostal movements who claim to use the early church as a role-model. / Dr. M. Nel Prof. L. Grundlingh