Les crues rapides sont considérées parmi les catastrophes naturelles les plus dangereuses en raison de leur imprévisibilité et la rapidité de leurs dynamiques spatio-temporelles. Même si ces évènements touchent généralement des petites étendues spatiales, elles causent un nombre important de victimes. Les différentes analyses des impacts des crues rapides pointent la mo- bilité quotidienne comme un facteur principal augmentant l’exposition et la vulnérabilité des individus : près de la moitié des victimes sont des automobilistes surpris par les submersions des routes durant leurs trajets quotidiens. C’est dans ce contexte que plusieurs travaux ont été conduits afin de développer des outils de prévision des coupures des routes par submersion dans le département du Gard, fréquemment exposé à des évènements hydro-météorologiques extrêmes. Ces études ont permis d’identifier les points de coupure, situés aux niveaux des intersections routes/rivières, vulnérables aux crues rapides et de développer des méthodes d’estimation du risque de submersion des routes.Cette thèse s’inscrit dans la continuité de ces travaux dans le but de quantifier et de caractériser l’exposition des individus aux crues rapides durant leurs mobilités. Pour cela, nous avons contribué au développement de MobRISK : un modèle de simulation de l’ex- position des automobilistes aux submersions des routes lors d’évènements de crues rapides. Une première application de MobRISK est présentée dans le but d’évaluer l’exposition d’une population d’un zone d’étude, située au nord-ouest du Gard, à l’évènement de crue rapide des 8-9 Septembre 2002.Les résultats de ce cas d’étude ont permis d’identifier un décalage entre les dynamiques temporelles du trafic simulé au niveau des points de coupure et des niveaux de submersion de ces points. Ce décalage temporel a probablement constitué un facteur de réduction du nombre de victimes sur la route. La combinaison des estimations de submersion des routes avec le trafic simulé a permis de localiser les routes qui ont présenté le plus de danger pour les automobilistes lors de cet évènement. Ensuite, l’évaluation de l’exposition individuelle aux submersions routières a permis d’identifier les profils socio-démographiques des automobilistes les plus exposés constitués majoritairement de jeunes actifs de sexe masculin.Enfin, différents scénarios de comportements en situation de crise ont été construits et tes- tés à travers l’intégration des décisions d’adaptation des déplacements face aux perturbations environnementales. La comparaison des effets des scénarios de comportements a permis de souligner le rôle important des règles adoptées dans les prises de décision et dans l’évaluation du danger dans la réduction l’exposition des automobilistes.Au final, cette thèse souligne les potentialités et les performances de MobRISK comme un outil innovant et prometteur pour la simulation de l’exposition sociale aux crues. / Flash floods are considered as ones of the most dangerous natural hazard due to their rapidness and suddenness that leave little time for exposed people to protect themselves. Although the relatively small spatial extension of those events, several studies showed strong human impacts regarding the number of affected people. Recently, daily mobility is pointed at as important social factor increasing individual exposure and vulnerability to flash flooding : almost half of the victims are motorists trapped while travelling on flooded roads. Therefore, several studies have been conducted for assessing roads’ sensitivity to flooding in the Gard area, frequently exposed to sever flash flood events.This thesis goes a step further by integrating social dimension in order to quantify and analyze road users’ exposure to flash flood during their itineraries. It contributes to the development of MobRISK : A simulation model for assessing motorists’ exposure to roads submersion by integrating individual travel-activity patterns and behavioral adaptation regarding weather disruptions. In order to assess population exposure to September 2002 flash flood event, we conducted an application of MobRISK in a study area located in the north-ouest of the Gard department.The results show that risk of flooding is mainly located in principal road links with considerable traffic load. However, a lag time between the timing of roads’ submersion and persons crossing these roads contributes to reduce the potential vehicle-related fatal accidents. It is also found that socio-demographic variables have significant effect on individual exposure and that young working males are the most exposed persons to road flooding. Finally, different behavior scenarios are built and tested by integrating individual travel adaptation decisions regarding perceived weather disruptions. The comparison of motorists’ exposure for each scenario highlights the important role of risk attitudes and threat evaluation processes on reducing population exposure.Thus, the proposed model demonstrates the benefits of considering spatiotemporal dy- namics of population exposure to flash flood and presents an important improvement in exposure assessment methods. Such improved characterization of road users’ exposure can present valuable information for flood risk management services and emergency planning.

Cette thèse aborde l’institutionnalisation du système socio-technique qui a permis la mobilité automobile entre 1920 et 1950 au Portugal, un pays qui au départ n’est pas producteur de véhicules automobiles et demeure périphérique technologiquement, par l’étude de deux aspects qui sont complémentaires : la régulation de la circulation des automobiles et l’adaptation des routes aux nouveaux véhicules motorisés. C’est une étude sur l’appropriation et la construction de ce système en fonction des actions menées par les usagers, les ingénieurs, les législateurs, les clubs automobiles, les services de voirie ou les organes de l’administration routière. Pendant la période analysée et malgré des taux de motorisation assez faibles, le système socio-technique est institutionnalisé et stabilisé, accompagnant et dialoguant avec la définition des standards internationaux et en créant des structures qui ont influencé le développement de ce système pendant la deuxième moitié du XXe siècle.La façon dont l’institutionnalisation du système a été menée à terme a non seulement permis une augmentation importante du transport routier commercial (au détriment du développement des chemins de fer), mais a aussi protégé une culture élitiste de l’usage des voitures particulières et le développement du tourisme automobile, visible dans la régulation de la circulation et dans la construction de routes touristiques avec des caractéristiques techniques et des budgets spéciaux. Elle a aussi permis le développement de l’ingénierie routière au Portugal avec la création d’un organe autonome d’administration routière et avec la formation de plusieurs ingénieurs qui ont construit une oeuvre que s’est approprié le discours de l’Estado Novo comme un symbole de sa réalisation et de sa modernité. Ces acteurs ont participé à l’élaboration de connaissances techniques ainsi qu’aux négociations de normes sociales et morales et à la construction de représentations au niveau des pratiques des usagers, des discours et de la matérialité de ce système. / This dissertation focuses on the institutionalization of the sociotechnical system, underlying automobility, in Portugal, from 1920 to 1950. By taking into consideration that the country was technologically peripheral and originally no automobiles were locally manufactured, this work developed along two complementary aspects: the regulation of automobile circulation and the adaptation of roads to the new vehicles. This is a study focusing on the appropriation and construction of this system through the interventions of users, engineers, legislators, automobile clubs, road services and administration. In the period under consideration, despite the low rates of motorization, the sociotechnical system institutionalized and stabilized, by following and discussing the definition of international standards and creating structures, which influenced the development of this system, during the second half of the nineteenth century.The way in which the institutionalization of the car system developed allowed not only an increase in commercial road transport in detriment of railways, but also protected an elitist culture regarding the use of private cars and the development of automobile tourism, as shown by circulation regulations and in the construction of tourism roads with special technical and budgetary characteristics. It also allowed the development of road engineering in Portugal, with the creation of an independent organ for road administration and the training of engineers whose works were appropriated by the rhetoric of the dictatorial regime known as New State (Estado Novo) as a symbol of its own accomplishments and modernity. All these actors participated in the construction of a technical discourse and in the negotiations of social and moral norms, as well as of representations at the level of the users’ practices, discourses and the materiality of the sociotechnical car system.Key-words: Sociotechnical system; automobile mobility, Portugal, Estado Novo, roads, motorists.

A crescente preocupação com o nível de risco associado ao transporte de materiais perigosos levou várias instituições internacionais a empenhar esforços na avaliação de risco em nível regional. Seguindo essa tendência, o objetivo deste trabalho foi analisar os mais recentes processos de análise de riscos decorrentes do transporte rodoviário de materiais perigosos. No presente trabalho foram avaliadas 21 metodologias de análise de riscos, desenvolvidas por vários autores e para diversas localidades. Em especial, duas foram revistas e discutidas: um método recentemente desenvolvido pelo Instituto Federal Suíço de Tecnologia (Nicolet-Monnier e Gheorghe, 1996) e a estratégia delineada pelo Center for Chemical Process Safety - CCPS (1995), levando em consideração a estimativa do risco individual e social. Também foram aplicados os modelos de Harwood et al. (1990) e de Ramos (1997), adaptados por Hartman (2003) à realidade das estradas do Estado de São Paulo. A extensão dessas metodologias foi explorada, a fim de encontrar as suas vantagens e desvantagens. Como estudo de caso o presente trabalho considerou o transporte de amônia ao longo de duas rotas possíveis por rodovias do Estado de São Paulo, incluindo uma parcela significativa de avaliação em área densamente povoada, obtendo-se os resultados utilizando uma das metodologias de analise de risco. A inovação proposta por esse trabalho foi a pesquisa, o desenvolvimento e a introdução de duas variáveis ao modelo proposto por Harwood et al. (1990). Essas variáveis ponderadoras no valor do risco foram: a idade do condutor e a zona de impacto conforme o período do dia em que o transporte foi realizado em função do volume do produto transportado. As alterações propostas têm como objetivo deixar o valor do risco mais sensível em relação ao tipo do produto transportado e a idade do condutor. As principais etapas processuais relacionadas com a análise quantitativa dos riscos para sistemas de transporte são suportadas pelos métodos precedentes para instalações fixas. Especial atenção foi dada à forma de coletar informações locais e para estimar coeficientes que refletissem as condições prevalecentes na região considerada no estudo de caso apresentado. / The increasing concern with the level of risk associated with the transportation of hazardous materials took some international institutions to pledge efforts in the evaluation of risk in regional level. Following this trend, the objective of this work was to analyze the most recent processes of analysis of risks from road transportation of hazardous materials. In the present work 21 methodologies of analysis of risks, developed by some authors and for diverse localities have been evaluated. Two of them, in special, have been reviewed and discussed: a method recently developed by the Swiss Federal Institute of Technology (Nicolet-Monnier and Gheorghe, 1996) and the strategy delineated by the Center for Chemical Process Safety CCPS (1995), taking into consideration the estimate of the individual and social risk. Also, the models of Harwood et al. (1990) and of Ramos (1997), adapted by Hartman (2003) have been applied to the reality of the roads of the state of São Paulo. The extension of these methodologies was explored, in order to find its advantages and disadvantages. As a study case the present work considered the ammonia transportation throughout two routes evaluating the reality of the roads of the state of São Paulo, including a significant parcel of evaluation in a densely populated area, getting the results using risk, at least, one of the methodologies mentioned above. The innovation proposed by this work was the research, the development and the introduction of two variables to the model considered by Harwood et al. (1990). These variables that influence in the value of the risk are: the age of the driver of truck and the zone of impact that is function type of product, period of the day where the transport was carried and the volume that has been transported. The aim of the proposed modifications is to let the value of the risk more sensible in relation to the type of the product carried and the age of the truck driver. The main related procedural stages with the quantitative analysis of the risks for transportation systems are supported by the preceding methods for fixed installations. Special attention was given on to how to collect local information and estimate those coefficients that represent the actual conditions of the region considered in the presented study case.

A dengue é doença causada pelo vírus dengue (DENV), que acomete cerca de 390 milhões de pessoas no mundo, representando uma ameaça à saúde pública mundial. Até o momento não se dispõe de tratamento específico ou de vacinas para a maioria da população. Um dos maiores obstáculos para o desenvolvimento de vacinas ou para a compreensão da biologia do vírus é a falta de modelos animais que mimetizem a doença vista em humanos. Neste trabalho, o principal objetivo foi a busca de modelos alternativos de infecção com um isolado clínico (JHA1) de DENV sorotipo 2 (DENV2) capaz de infectar camundongos imonocompetentes após administração pela via intracraniana. Foram testadas duas vias alternativas de inoculação viral (intraperitoneal e intravenosa) em camundongos adultos imunocompetentes, além da via intracraniana em camundongos C57BL/6. Por fim, tentativas de mapeamento de mutações relacionadas à neurovirulência do JHA1 em camundongos imunocompetentes. Os resultados obtidos contribuem para a caracterização do JHA1 e para a busca de modelos experimentais alternativos de DENV. / Dengue fever is a disease caused by the dengue virus (DENV), which affects around 390 million people worldwide, posing a threat to global public health. To date, there is no specific treatment or vaccination for the majority of the population. One of the major obstacles to vaccine development or understanding the biology of the virus is the lack of animal models that mimic the disease seen in humans. In this work, the main objective was to search for alternative models of infection with a clinical isolate (JHA1) of DENV serotype 2 (DENV2) capable of infecting immunocompetent mice after administration by the intracranial route. Two alternative routes of viral inoculation (intraperitoneal and intravenous) were tested in immunocompetent adult mice, in addition to the intracranial route in C57BL/6 mice. Finally, attempts to map mutations related to JHA1 neurovirulence in immunocompetent mice. The results obtained contribute to the characterization of JHA1 and to the search for alternative experimental models of DENV.

As células-tronco adultas possuem capacidade de se transformar em certos tipos de tecidos. Surge desta forma, uma nova modalidade de tratamento para doenças cardíacas, assim, uma avaliação na distribuição e quantificação do número de células por diferentes vias de infusão tornam-se importantes, pois o microambiente e interação célula/célula interferem no processo de transdiferenciação e/ou fusão. Foram utilizados nove cães, com peso entre 25 e 30kg e hígidos, no qual foi realizada punção, separação, marcação e infusão de células mononucleares da medula óssea pelas vias intracoronariana, transendocárdica e venosa retrógrada. Pôde-se observar a presença de células por todo tecido cardíaco em todas as vias, contudo o padrão de distribuição das mesmas difere, no qual há um predomínio de células em tecido conjuntivo, principalmente em epicárdio nas vias transendocárdica e venosa retrógrada e um padrão intersticial muscular intracoronariana. Há diferenças significativas na quantidade de células nas regiões apical, basal, medial e apical quando relacionada à via de infusão (P<0,01). / The adult stem cells have a capacity to transform in different kinds of tissue. It is emerges like a new treatment modality of cardiac diseases, so, an evaluation in cell distribution and quantification by different routes of infusion in heart are necessary, because the microenvironment and the interaction cell/cell age in the transdifferentiation and fusion process. It was used 09 healthy mongrel dogs, with 25 -30kg of weight, which was performed a punction of iliacal crest, bone marrow mononuclear cells separation by Ficoll density, stained with Hoechst and infusion by intracoronary, transendocardial and retrograde routes. The marked cells was observed in all cardiac tissue, however, the pattern of distribution of the same ones differs, however in the transendocardial and retrograde route the cells could be founded mainly into the connective tissue - epicardium and sub-epicardic connective tissue and in the intracoronary route, the cells was observed mainly in the muscular interstice. It was observed a significant number of cells in the atrial, basal, medium and apical cardiac region when related with the route of infusion.

Entre le XIIe et XVIe siècle, sous les dynasties ayyoubide puis mamelouke, les routes du Bilād al-Šām étaient jalonnées de gîtes d’étapes pouvant fournir un abri aux voyageurs de toute sorte. Cette thèse se propose d’approfondir la connaissance de ces édifices en suivant deux axes de recherche principaux. Le premier objectif consiste dans l’étude de tous les aspects relatifs aux caravansérails en tant qu’édifices : leurs fonctions,leurs équipements et, surtout, leur architecture et les techniques constructives qui les caractérisent. Il s’agit ensuite de proposer une reconstitution du réseau routier syrien qui prenne en compte également la distribution de ces édifices le long des routes. En partant de l’établissement d’un nouvel inventaire des gîtes d’étapes et d’une tentative de redéfinition de la notion de caravansérail routier, la recherche se développe progressivement à travers un double angle d’approche historique et archéologique. Ce dernier aspect se traduit par la mise en place d’une chronotypologie des techniques constructives et par l’étude stratigraphique approfondie d’un des caravansérails routiers encore conservés, afin d’identifier ses différentes phases d’évolution. Le travail de recherche est enfin complété par un catalogue présentant en détail les différents sites identifiés. / Between the XII and XVI century, under the Ayyubid and Mamluk dynasties, the roads of Bilād al-Šām weredotted by wayside caravanserais that provided shelter to all kind of travellers. The purpose of this thesis is toimprove these edifices’ knowledge focusing on two main axis of research. The first aim of the work is toinvestigate all the aspects dealing with the caravanserai as a building, from its function and facilities to itsarchitecture and building techniques. Secondly, the objective is to propose a reconstruction of the Syrian roadnetwork which could also be supported by the spatial distribution of road caravanserais. Starting from thecreation of a new list of sites, also based on the development of a new definition of wayside caravanserai, theresearch work develops following a double point of view, both historical and archaeological. This latter aspectmaterialises through the establishment of a chronotypology of the building techniques, and through the detailedstratigraphic analysis of one of the preserved sites, in order to identify its different evolution phases. The studyis finally completed by a catalogue which presents in detail all the different road caravanserais we couldidentify.

No presente trabalho, optou-se por adotar preceitos teóricos e metodológicos fundamentados nos princípios da interdisciplinaridade, a fim de melhor compreender os processos que resultaram na construção da Paisagem em estudo, a partir da lógica da rede viária romana do Noroeste Peninsular, pois são grandes eixos com uma influência persistente na morfologia histórica. Reconhecendo, assim, que sua incorporação na análise arqueológica pressupõe sua abordagem como um sistema complexo e dinâmico no qual diferentes fatores - naturais, culturais, materiais, econômicos, ideológicos e políticos - interagem e evoluem conjuntamente. Daí a opção pela perspectiva metodológica denominada Arqueologia da Paisagem vinculada ao ferramental Geotecnológico. É nesse sentido que aplicamos uma metodologia de estudo utilizando o ferramental geotecnológico interagindo com outras fontes disponíveis, tais como: fontes textuais, itinerários, epigrafia, miliários, pontes, dados ambientais e arqueológicos. As geotecnologias permitem integrar o conhecimento geográfico com o conhecimento arqueológico e historiográfico. Esses aspectos viabilizam uma análise mais integrada das redes viárias antigas, em particular dos itinerários que ligavam as três capitais conventuais do Noroeste Peninsular Romano fundadas por Augusto: Bracara Augusta, Lucus Augusti e Asturica Augusta. A partir da análise de cálculos de rotas ótimas foi possível observar que a lógica de mobilidade da rede viária romana, iniciada com a reorganização administrativa implementada por Augusto, priorizava ligações entre núcleos urbanos localizados em pontos estratégicos de controle do território e de tráfego de mercadorias. Dessa forma, as vias, além de estabelecerem ligações, a escalas variadas, entre os principais aglomerados populacionais, também garantiam a defesa e afirmação do poder de Roma sobre os territórios conquistados. / In the present work, it was decided to adopt theoretical and methodological precepts based on the principles of interdisciplinarity, in order to better understand the processes that resulted in the construction of the Landscape under study, based on the logic of the Roman road network of the North-West Peninsular, axes with a persistent influence on historical morphology. Therefore, it is important to note that this is a complex and dynamic system in which different factors - natural, cultural, material, economic, ideological and political - interact and evolve together. Hence the option for the methodological perspective called Landscape Archeology linked to the Geotechnological tooling. It is in this sense that we apply a methodology of study using the geotechnical tooling interacting with other available sources, such as: textual sources, itineraries, epigraphy, miliaries, bridges, environmental and archaeological data. Geotechnologies allow the integration of geographic knowledge with archaeological and historiographic knowledge. These aspects make possible a more integrated analysis of the old road networks, in particular the itineraries that linked the three conventual capitals of the Roman Northwest founded by Augustus: Bracara Augusta, Lucus Augusti and Asturica Augusta. From the analysis of optimum route calculations, it was possible to observe that the mobility logic of the Roman road network, initiated with the administrative reorganization implemented by Augustus, prioritized links between urban nuclei located at strategic points of territory control and traffic of goods. In this way, the routes, other establishing connections, at different scales, between the main population groups, also guaranteed, the defense and affirmation of the power of Rome over the conquered territories.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Atualmente, a dengue à considerada a arbovirose mais importante do mundo, emergindo em paÃses onde a doenÃa parecia erradicada e ressurgindo em paÃses onde antes estava sob controle. Apesar de todos os esforÃos de pesquisa empreendidos na produÃÃo e desenvolvimento de uma vacina contra a doenÃa, ainda nÃo se dispÃe de uma terapia preventiva eficaz; a Ãnica alternativa de manejo nos dias atuais se dà atravÃs do combate ao Ãnico elo vulnerÃvel, o mosquito vetor Aedes aegypti. Apesar dos programas de manejo das populaÃÃes de vetores disporem de vÃrias opÃÃes de inseticidas sintÃticos, o surgimento de populaÃÃes resistentes apresenta-se como um entrave no controle desse mosquito vetor. AlÃm do monitoramento dessas populaÃÃes resistentes, tornou-se evidente que estudos moleculares podem ser a chave para o manejo sustentÃvel desses vetores. Assim, o presente trabalho teve por objetivo avaliar as alteraÃÃes na expressÃo proteica de larvas de Ae. aegypti tratadas com o larvicida orgÃnico m-pentadecadienil-fenol, um lipÃdeo fenÃlico isolado de sementes de Myracrodruon urundeuva a fim de elucidar os possÃveis mecanismos de detoxificaÃÃo e resposta molecular a esse composto. Para isso foi realizada eletroforese bidimensional (focalizaÃÃo isoelÃtrica seguida de eletroforese em gel de poliacrilamida em condiÃÃes desnaturantes - SDS-PAGE) de larvas de terceiro estÃdio tratadas com m-pentadecadienil-fenol, em concentraÃÃes subletais (CL50 10,16 Âg.mL-1), em comparaÃÃo com um grupo controle nÃo tratado. Treze spots foram identificados como diferencialmente expressos, e doze foram identificados consistentemente em bancos de dados apÃs anÃlise dos espectros obtidos por espectrometria de massas (ESI-Q-ToF). ApÃs a anÃlise das vias nas quais essas proteÃnas estÃo envolvidas, foi proposto que o larvicida m-pentadecadienil-fenol elicita a superexpressÃo de proteÃnas que promovem a formaÃÃo de barreiras mais eficientes, e que uma vez dentro das cÃlulas promove um estresse oxidativo que leva ao aumento do metabolismo de degradaÃÃo lipÃdica, desestabilizaÃÃo da membrana lisossomal, aumento do metabolismo em resposta ao estresse tÃxico e possivelmente resulta em morte celular programada (apoptose). / Currently, dengue fever is considered the most important arboviral disease in the world, emerging in countries where the disease seemed eradicated and reappearing in countries where before was under control. Despite all the efforts to produce and develop a vaccine against the disease, there is not a preventive therapy. Nowadays, the disease management is through the eradication of the mosquito vector Aedes aegypti. Despite the several options of synthetic insecticides available for management programs of vector populations, the emergence of resistant populations is presented as an obstacle in mosquito control vector. In addition to monitoring these resistant populations, it became evident that molecular studies may be the key to the sustainable management of these vectors. Thus, the present study aimed to evaluate the changes in protein expression of Ae. aegypti larvae treated with the organic larvicide m-pentadecadienil-phenol, a phenolic lipid isolated from Myracrodruon urundeuva seeds to elucidate the putative mechanisms of detoxification and molecular response to this compound. For this, two-dimensional electrophoresis (isoelectric focusing followed by electrophoresis in polyacrylamide gel under denaturing conditions - SDS-PAGE) of third-instar larvae treated with m-pentadecadienil-phenol, at sublethal concentrations (LC50 10.16 microg.mL-1) was performed. The results were compared to a non-treated group. Thirteen spots were identified as differentially expressed, and twelve were consistently identified in databases analysis of the spectra obtained by mass spectrometry (ESI-Q-ToF). After analysis of the pathways in which these proteins are involved, it was proposed that the larvicide m-pentadecadienil-phenol elicits the overexpression of proteins that promote the formation of more efficient barriers and that once inside the cells, it promotes oxidative stress which leads to increased lipid degradation metabolism, destabilization of lysosomal membrane, increased metabolism in response to stress due to the moleculeâs toxicity and possibly results in programmed cell death (apoptosis).

This dissertation presents a new perspective on the function of objects in late-medieval devotional practice through a study of the so-called Soissons group of thirteenth-century French Gothic ivories. These ivory diptychs were sophisticated tools constructed to guide the user through various spiritual exercises that led to prayer. The hitherto unexplained increase in the availability of ivory in mid-thirteenth-century France is accounted for by an alteration in the trade routes that brought elephant tusks from the Swahili coast of Africa to northern Europe: a newly-opened passage through the Straits of Gibraltar allowed a small amount of luxury goods to be shipped together with bulk materials necessary to the northern textile industries. The increasing supply required a revision of the structure of the thirteenth-century craft of ivory. The Soissons group, the first ivory diptychs fashioned during this time of growth in ivory markets, is subdivided into two sections. An itinerant master who traveled throughout the Picard region between 1235 and 1270 crafted the first group. Concurrently, three separate Parisian artists produced the second group based on a Picard model. This dissertation redates all the ivories substantially earlier than previously thought, conclusions which were attained through stylistic analysis. The dense Passion iconography shaped the diptychs’ function in private devotion. The narrative encouraged the viewer to practice a number of spiritual exercises—reading, memorization and compunction—analogous to the three reasons for allowing images in the Christian Church, the triplex ratio. The Passion diptych format introduced with these objects was immensely popular throughout the thirteenth and fourteenth centuries and its conservation over time underscored its effectiveness. The small differences in iconography and composition among the seven Soissons diptychs, however, were subtle modifications to adjust to different audiences and to hone the objects’ efficacy as tools for prayer.

This dissertation presents a new perspective on the function of objects in late-medieval devotional practice through a study of the so-called Soissons group of thirteenth-century French Gothic ivories. These ivory diptychs were sophisticated tools constructed to guide the user through various spiritual exercises that led to prayer. The hitherto unexplained increase in the availability of ivory in mid-thirteenth-century France is accounted for by an alteration in the trade routes that brought elephant tusks from the Swahili coast of Africa to northern Europe: a newly-opened passage through the Straits of Gibraltar allowed a small amount of luxury goods to be shipped together with bulk materials necessary to the northern textile industries. The increasing supply required a revision of the structure of the thirteenth-century craft of ivory. The Soissons group, the first ivory diptychs fashioned during this time of growth in ivory markets, is subdivided into two sections. An itinerant master who traveled throughout the Picard region between 1235 and 1270 crafted the first group. Concurrently, three separate Parisian artists produced the second group based on a Picard model. This dissertation redates all the ivories substantially earlier than previously thought, conclusions which were attained through stylistic analysis. The dense Passion iconography shaped the diptychs’ function in private devotion. The narrative encouraged the viewer to practice a number of spiritual exercises—reading, memorization and compunction—analogous to the three reasons for allowing images in the Christian Church, the triplex ratio. The Passion diptych format introduced with these objects was immensely popular throughout the thirteenth and fourteenth centuries and its conservation over time underscored its effectiveness. The small differences in iconography and composition among the seven Soissons diptychs, however, were subtle modifications to adjust to different audiences and to hone the objects’ efficacy as tools for prayer.