Trots att e-handeln har ökat under de senaste decennierna, är konverteringsgraden för onlinebutiker inom modesegmentet fortfarande låg. Detta kan bero på det fenomen som kallas “shopping cart abandonment”, vilket innebär att kunder lägger varor i sina virtuella varukorgar men inte sluför köpet. Det finns många anledningar till varför kunderna agerar på detta sätt. En av de vanligaste orsakerna är att det föredragna betalningsalternativet inte är tillgängligt. Eftersom alla fall av shopping cart abandonment innebär en förlorad försäljning är det viktigt för onlineföretag att arbeta mot en högre konverteringsgrad då även den minsta ökningen av slutförda köp innebär en ökad lönsamhet. Därför bör det vara av intresse för alla onlineföretag att upprätta rutiner för att se till att kunderna kommer att slutföra sina köp. Ett sätt att göra detta är att påminna kunderna via e-mejl om produkterna i den övergivna kundvagnen. Dessa mejl kallas reaktiveringsmejl och innebär i grunden att företaget skickar ett mejl till de kunder som övergivit sin virtuella varukorg. Huvudfokus i denna studie är reaktiveringsmejl med syfte att undersöka hur e-handelsföretag inom mode och textilbranschen använder reaktiveringsmejl och om de i så fall sett en ökning i konverteringsgraden. För att uppfylla syftet har två olika datainsamlingsmetoder använts. Först och främst genomfördes ett experiment bland e-handelsföretag inom det valda segmentet för att på så vis få en bild av hur vanligt det är att använda reaktiveringsmejl. Efter detta genomfördes telefonintervjuer med ett antal av dessa företag för att få en mer djupgående förståelse kring reaktiveringsmejl. Undersökningens resultat visar att användningen av dessa e-postmeddelanden inte är så vanlig, men däremot att det är ett framgångsrikt sätt att minska förekomsten av shopping cart abandonment samt öka konverteringsgraden. / Even though e-retail has increased over the last few decades, the conversion rate for online stores in the fashion segment is still relatively low. This might be due to a phenomenon called “shopping cart abandonment”, which means that online customers place products in their virtual carts but never follow through with a purchase. There are many reasons why customers balk before the very last click. One of the more common causes is that the preferred payment option is not available. However, since all cases of shopping cart abandonment mean lost sales, it is important for online companies to work towards a higher conversion rate since even the smallest increase in completed purchases results in increased profitability. Therefore, it should be of interest for all online enterprises to establish procedures to ensure that customers will complete their online purchases. One way to do this is to remind the customers via e-mail about the products in the abandoned cart, which is called reactivation e-mails, and basically means that online companies send e-mails to the customers who abandoned their virtual carts. The main focus for this thesis is reactivation e-mails, with the purpose to examine how online enterprises in the fashion and textile segment use reactivation e-mails and if they have seen an increase in their conversion rate. To fulfill the purpose, companies within the chosen segment that offer online retail to their customers, have been interviewed about the subject and the findings show that the use of these e-mails is an effective way to increase the conversion rate and decrease the occurrence of shopping cart abandonment. Two different methods for data collection have been used for this study. Firstly, an experiment was conducted among e-commerce companies within the selected segment in order to determine how common it is to use reactivation emails. Secondly, telephone interviews were conducted with several of these companies to gain a deeper understanding of reactivation emails. The results of this survey show that the use of these emails is not very common, but it is clearly a very effective way to reduce the occurrence of shopping cart abandonment. It also increases conversion rates and given the relatively low cost to implement, it should be embraced industry wide.

L'objectif de cette thèse est d'étudier un aspect de la compréhension de textes ; la construction de la représentation mentale et le maintien de la cohérence, en fonction des capacités mnésiques du lecteur. Pour comprendre un texte, le lecteur est amené à élaborer une représentation mentale de la situation évoquée par celui-ci (i.e., le modèle de situation). Pour cela, il doit tout au long de la lecture mettre en relation les informations en cours de traitement avec celles préalablement traitées et supprimer des informations devenues non pertinentes afin de maintenir la cohérence de la signification qu'il est en train de construire (Kintsch, 1998 ; Gernsbacher, 1990). Les compétences mnésiques sont donc essentielles dans la mise en place de cette cohérence. Par ailleurs, cette recherche de cohérence devrait se faire à partir de plusieurs dimensions du texte, à savoir la spatialité, la temporalité, la causalité, et l’émotion (Zwaan, Langston & Graesser, 1995). Notre premier objectif a été de mettre en évidence l’existence du processus de suppression des informations spatiales lors de la construction de la représentation mentale. Pour cela, nous avons présenté des textes contenant deux informations spatiales, l’une de ces informations a été développée de façon préférentielle (l’autre devenant non pertinente) et nous avons fait varier la quantité de données textuelles présentées selon les textes. Ce protocole nous a ainsi permis de tester l’inhibition (i.e., mise en retrait), et la suppression de ces informations spatiales. Pour étudier le lien entre les capacités mnésiques et le processus de suppression, nous avons utilisé une épreuve qui teste la capacité de la mémoire de travail des participants (i.e. les blocs de Corsi). Notre deuxième objectif était de tester de façon approfondie la mise en place des processus d’inhibition et de suppression lors de la lecture d’un texte en fonction du type d’information présentée (pertinentes, non pertinentes et incohérentes avec l’histoire du texte).Les résultats obtenus nous ont permis de conclure à l’existence d’un processus d’inhibition qui intervient pour les informations incohérentes d’un texte, et d’un mécanisme de suppression intervenant pour des informations non pertinentes. De plus les informations incohérentes semblent être d’abord inhibées avant d’être définitivement supprimées de la représentation mentale du texte. Ces deux processus sont indispensables à la construction d’un modèle de situation cohérent d’un texte. / The objective of this research is to study an aspect of comprehension text; the construction of the mental representation and the preservation of coherence, according to working memory capacities of the reader. To understand a text, the reader is brought to elaborate a mental representation of the situation evoked by this one (i.e., the model of situation). To this aim, the reader should put in relation the information in the course of treatment with those handled earlier and delete information became irrelevant to maintain the coherence of the meaning (Kintsch, 1998; Gernsbacher, 1990). Memorial skills are thus essential in the implementation of this coherence. Besides, this research of coherence should be made from several dimensions of the text, namely the spatiality, the temporality, the causality, and the emotion (Zwaan, Langston and Graesser, on 1995).Our first objective was to highlight the existence of the mechanism of suppression of the spatial information during the construction of the mental representation. For that purpose, we presented texts containing two spatial informations, one of this information was developed in a preferential way (the other one becoming irrelevant) and we made vary the quantity of textual data presented according to texts. This protocol allowed us to test the inhibition, and the suppression of this spatial information. To study the link between working memory capacities and the process of suppression, we used a test that evaluates the capacity of the working memory of the participants (i.e. Corsi’s blocks).Our second objective was to test in a more complete way the implementation of inhibition and suppression processes during reading of a text according to the type of presented information (relevant, irrelevant and incoherent with the story of the text).Obtained results allowed us to confirm the existence of a process of inhibition which intervenes for the incoherent information of a text, and a mechanism of suppression occurring for the irrelevant information. The inconsistent information seems to be inhibited at first, before definitively eliminated by the mental representation of the text. These two processes are necessary to the construction of a coherent model of situation of a text.

In the present work the effect of isothermal ageing treatment on the microstructure and on the localized corrosion resistance of a duplex stainless steel (DSS) was investigated. Specimens taken from a hot rolled cylindrical duplex stainless bar with 22% Cr grade were solution annealed at 1050&deg / C and then sensitization heat treatments were conducted at 650, 725 and 800&deg / C with duration ranging from 100 to 31622 min. The microstructural changes were examined by the light optical microscopy (LOM) and scanning electron microscopy (SEM). XRD technique and EDS analysis were used for microstructural evolution. Double Loop Electrochemical Potentiodynamic Reactivation (DLEPR) and standard weight loss immersion acid tests were performed in order to determine the degree of sensitization (DOS) to intergranular corrosion. The surfaces remained after the DLEPR test and the weight loss immersion test were also examined to observe the attack locations and their relationship with the chromium depleted zones. The degree of sensitization is measured by determining the ratio of the maximum current generated by the reactivation (reverse) scan to that of the anodic (forward) scan, (Ir/Ia) x 100. Ir is very small (less than 10-5 A/cm2) for solution annealed samples at 1050&deg / C for 1 hr and those aged at 650&deg / C for 100 and 316 min after the solution heat treatment, with the Ir/Ia ratios of 0.027634%, 0.033428% and 0.058928% respectively. Hence these samples were considered as unsensitized and their microstructure was composed of primary ferrite and austenite. However, Ir increased to values as high as 10-2 A/cm2 and even approached Ia for all samples aged for other temperatures and times, associated with high Ir/Ia ratios. The increased degree of sensitization can be attributed to stronger effect of chromium and molybdenum depleted areas. The microstructure was composed of primary ferrite and austenite including also sigma phase and the secondary austenite that would be responsible for the localized chromium impoverishment. The time required for sensitization was shorter in samples aged at higher temperatures. Accordingly ageing times of 1000 min at 725&deg / C and of 316 min at 800&deg / C were sufficient, whereas times longer than 10000 min was needed to achieve a sensitized structure at 650&deg / C.

While the latent genome of most Herpesviruses persists as a nuclear circular episome, previous research has suggested that Human Herpesvirus 6 (HHV-6) may integrate into host cell chromosomes, and be vertically transmitted in the germ-line. Because the HHV-6 genome encodes a perfect TTAGGG telomere repeat array at the right end direct repeat (DRR) and an imperfect TTAGGG repeat at the end of the left end direct repeat (DRL), we established a hypothesis that during latency, the HHV-6A and HHV-6B genome integrates into the telomeres of human chromosomes through homologous recombination with the n(TTAGGG) viral repeats, and the integrated virus can be induced to lytic replication. We sought, first, to definitively illustrate the in vitro and in vivo integration of HHV-6A and HHV-6B. Following infection of naïve Jjhan and HEK-293 cell lines by HHV-6A and Molt3 cell line by HHV-6B, the virus integrated into telomere of chromosomes. Next, peripheral blood mononuclear cells (PBMCs) were isolated from families in which several members, including at least one parent and child, had unusually high copy numbers of HHV-6 DNA per ml of blood. FISH confirmed that HHV-6 DNA co-localized with telomeric regions of one allele on chromosomes 17p13.3, 18q23, and 22q13.3, while the integration site was identical among members of the same family. Partial sequencing of the viral genome identified the same integrated HHV-6A strain within members of families, confirming vertical transmission of the viral genome through the germ-line [inherited HHV-6 (iHHV-6)]. Amplification and sequencing of the HHV-6A and more recently HHV-6B viral-chromosome junction identified DRR integrated into the telomere directly adjacent to the subtelomere of the chromosome. After mapping the DRR of iHHV-6, we subsequently focused on determining if the DRL was present in the integrated genome and whether the remaining telomere sequence of the chromosome was extended beyond the DRL. Southern hybridization of PCR amplified HHV-6 integrated cell lines and iHHV-6 patients PBMCs indicate the presence of DRL within the integrated viral genome. Therefore, the genomic structure of the iHHV-6 is as follows: chromosome-subtelomere-(TTAGGG)5-41-DRR-U-DRL-(TTAGGG)n. During latent integration, no circular episomes were detected even by PCR. However, trichostatin-A treatment of PBMCs and in vitro integrated HEK-293 cells induced the reactivation of iHHV-6 from its latent integrated state. We demonstrated the induction of integrated iHHV-6 with trichostatin-A lead to the excision of the integrated genome and generation of the U-DR-U junction which signifies circularization and/or concatemer formation of the viral genome through rolling-circle replication. Taken together, the data suggests that HHV-6A and HHV-6B are unique among human herpesviruses: they specifically and efficiently integrate into telomeres of chromosomes during latency rather than forming episomes, and the integrated viral genome is capable of producing virions.

Il a été suggéré que lorsqu’une trace de mémoire consolidée est rappelée (réactivée), elle devient instable et sujette aux modifications avant de se stabiliser à nouveau en mémoire à long terme. Nous avons récemment démontré que lorsque la réactivation d’un souvenir négatif est couplée à l’exposition à un stress psychosocial, le souvenir de l’évènement négatif est augmenté de façon durable. En se basant sur ces résultats, le but de cette thèse est de préciser le rôle du stress psychologique et physiologique (hormones de stress) sur la modulation de souvenirs réactivés. Plus précisément, la première étude visait à déterminer si le cortisol, hormone de stress majeure, est un joueur clé dans la modulation des souvenirs réactivés. Pour ce faire, nous avons inhibé pharmacologiquement les niveaux de cortisol au moment de la réactivation d’un souvenir contenant des segments neutres et négatifs. Les résultats démontrent que la réactivation du matériel négatif est amoindrie lorsque les niveaux de cortisol sont inhibés, et cet effet est toujours présent quatre jours plus tard. Étant donné que les stimuli utilisés jusqu’à maintenant ont une faible validité écologique, nous avons voulu déterminer si d’autres types de mémoires pouvaient également être modulables lors de leur réactivation. L’objectif de la deuxième étude était donc de déterminer si les mémoires autobiographiques collectives sont modulables par le stress au moment de leur réactivation. Pour ce faire, nous avons exposé les participants à de vrais extraits de journaux, neutres ou négatifs, afin de réactiver les mémoires collectives associées à ces évènements. Par la suite, tous les participants ont été exposés à un stress psychosocial et leur mémoire des extraits a été évaluée la journée suivante. Les résultats démontrent que les femmes ayant lu les nouvelles négatives avaient une réactivité physiologique accrue face au stresseur et une mémoire augmentée de ces mêmes nouvelles le jour suivant. Ce phénomène n’était cependant pas observable chez les hommes. Le but de la troisième étude était de déterminer si les mémoires autobiographiques personnelles sont modulables par le stress au moment de leur réactivation. Nous avons demandé aux participants de se remémorer deux évènements de leur passé, négatifs ou neutres. Par la suite, ils ont été exposés à un stress psychosocial et leur mémoire pour ces mêmes évènements a été évaluée à nouveau la journée suivante. Les résultats démontrent que les mémoires autobiographiques personnelles réactivées ne semblent pas être modulables par l’exposition à un stresseur. Globalement, les résultats de cette thèse démontrent que le cortisol a la capacité de moduler des souvenirs négatifs réactivés, mais que la nature (extrinsèque vs. intrinsèque) et l'intensité des souvenirs réactivés sont des facteurs déterminants pour que ce phénomène prenne place. / It has been suggested that when a consolidated memory trace is recalled (reactivated), it becomes active and sensitive to modifications before stabilizing again in the long-term memory system. We have recently demonstrated that when the reactivation of a negative memory is followed by exposition to a psychosocial stressor, the memory for the negative material is enhanced in a long-lasting manner. Based on these results, the goal of this thesis is to clarify the role of physiological (stress hormones) and psychological stress on the modulation of reactivated memories. More precisely, the first study aimed to determine whether cortisol, a major stress hormone, is a key player in the modulation of reactivated memories. To do so, we have pharmacologically inhibited cortisol levels at the time of reactivating a memory composed of neutral and negative segments. Results showed that the reactivation of the negative material is decreased when cortisol levels are inhibited and this effect is still present four days later. Given that the stimuli used so far have a weak ecological validity, we wanted to determine whether other types of memories could also be modified upon their reactivation. The goal of the second study was to examine whether collective autobiographical memories were sensitive to the effects of stress at the time of reactivation. To do so, we have exposed participants to real newspaper excerpts, either neutral or negative, in order to reactivate the collective memories associated to these events. We have then exposed all the participants to a psychosocial stressor and their memory for the excerpts was assessed the following day. Results showed that women who have read negative news excerpts had a more pronounced physiological reactivity to the stressor and an increased memory for these news the following day. This phenomenon, however, was not observed in men. The goal of the third study was to determine whether personal autobiographical memories were sensitive to the effects of stress at the time of their reactivation. We have asked participants to recall two personal events, either negative or neutral. We then exposed them to a stressor and their memory for these events was tested the following day. The results showed that reactivated personal autobiographical memories were not sensitive to stress. Globally, the results of this thesis show that cortisol has the capacity to modulate reactivated negative memories, but that the nature (extrinsic vs. intrinsic) and the intensity of the memories are determining factors for this phenomenon to occur.

A evolução da margem continental do sudeste do Brasil tem sido discutida por diversos autores desde meados do século passado até os dias atuais, especialmente no contexto da origem e evolução dos escarpamentos e das bacias tafrogênicas. Buscou-se contribuir com novos dados sobre a evolução da área a partir da aplicação da termocronologia de baixa temperatura (U-Th)/He em apatita, que oferece uma sensibilidade significativa para registrar movimentações tectônicas na crosta superior. Foi possível obter idades em 107 cristais de apatita de 18 amostras do embasamento coletadas no perfil com orientação NW-SE, numa seção entre a Serra da Mantiqueira e o Gráben da Guanabara. As idades corrigidas variam entre 250,1 8,7 Ma e 43,5 1,9 Ma (2 σ) e as não corrigidas entre 174,13 3,03 Ma e 27,07 0,60 Ma (1 σ). O Neocretáceo, o Eocretáceo e o Paleoceno são os principais registros no conjunto de dados, em ordem de importância. No Neocretáceo, o intervalo entre 83,6 e 72,1 Ma (Campaniano) representa o maior destaque nos registros termocronológicos, embora os outros registros (Maastrichtiano e Santoniano) também estejam presentes e sejam importantes. As idades do Neocretáceo destacam a importância dos eventos tectonomagmáticos e soerguimento regional na história térmica dessa área, inclusive com idades (~86 Ma) atribuídas ao contexto de soerguimento da Serra do Mar. As idades do Eocretáceo indicam o registro de eventos térmicos mais antigos, vinculados à evolução pré-rifte. Já os dados do Paleoceno estariam associados ao evento de reativação responsável pela implantação do sistema de riftes continentais (~65 Ma) e as idades do Eoceno, restritas à borda de falha da bacia de Resende (49,7 Ma e 43,5 Ma), à reativação do sistema de riftes nessa área. A dispersão de idades foi interpretada como efeito dos danos de radiação já que muitos grãos apresentam correlação entre idade e concentração de urânio (eU). Os padrões de tempo-temperatura (t-T), definidos a partir dos modelos HeFTy calibrados para o modelo de difusão que considera os efeitos de danos de radiação nos cristais, registraram eventos de resfriamento rápido, os quais mostram correlação direta com episódios de reativação e soerguimento na margem continental e com registros nas bacias continentais e marginais. O padrão de aumento das idades com a elevação, assim como da costa em direção ao interior é observado, mas mostra-se alterado pela ocorrência de idades mais jovens associadas à complexa evolução dessa margem continental com desnivelamentos de blocos vinculados à tectônica pós-rift, numa situação que ressalta a influência dos episódios de reativação. As estimativas de denudação total variam entre 1,2 e 2,8 km. As taxas de erosão variam entre 15,2 e 35,3 m/Ma. A evolução da área indica não apenas a influência de um evento específico mas, possivelmente, uma combinação de episódios que se alternaram e/ou atuaram em conjunto em determinados períodos. Os eventos de reativação mais antigos, combinados com os mais recentes, exibem os seus remanescentes na paisagem (serras da Mantiqueira e do Mar e os grábens e bacias sedimentares) e assumem papel fundamental na evolução da área. Os registros de tais episódios podem ser observados nas histórias térmicas das rochas e nos depósitos correlativos nas bacias sedimentares marginais e intracontinentais. / This doctoral dissertation involves low-temperature thermochronologic investigations to constrain the Mesozoic and Cenozoic tectonic reactivation of the continental margin of southeast Brazil. The study area is located in a segment of the Neoproterozoic Ribeira belt in southeastern Brazil, which occupied a central position in Western Gondwana. Lately, during the Mesozoic and Cenozoic, fault zones related to the development of the continental rifts in southeast Brazil reactivated. Using apatite (U-Th)/He thermochronology (AHe), we have presented the results of analysis on 107 apatite crystals of basement samples collected from a NWSE transect in the Mantiqueira Mountains to the Guanabara Graben, as well as from the NESE transverse faults. The data range from 27.07 0.60 Ma to 174.13 3.03 Ma (1 σ) for uncorrected ages, and from 43.5 1.9 Ma to 250.1 8.7 Ma (2 σ) for corrected ages. The Neo-Cretaceous, Eo-Cretaceous, and Paleocene are the main recorded AHe ages, in order of importance. The Eo-Cretaceous ages indicate the occurrence of older thermal events related to a pre-rifting phase (~121 Ma). The Neo-Cretaceous ages signify the importance of tectonic and magmatic events, and regional uplifting for the thermal history of the study area, including ages related to the Serra do Mar Mountains uplift (~86 Ma). Paleocene ages seem to be related to the reactivation (~65 Ma), which was responsible for the continental rifts in the southeastern Brazil. Finally, the Eocene ages (49.7 Ma and 43.5 Ma), which are from samples restricted to the Resende Basin border faults, indicate a continental rift reactivation. We investigated the age dispersion data, which were interpreted as an effect of radiation damage. Several samples show correlations between apatite (U-Th)/He age and effective U concentration (eU). We have applied HeFTy thermal modeling to obtain timetemperature (t T) paths using a radiation damage diffusion model. Inverse modeling of (U-Th)/He age data suggests rapid cooling episodes for all samples. The main thermal events recorded by the HeFTy models show a direct correlation with the timing of regional tectonic events: reactivation phases, continental margin uplift, and the sedimentary record. Apatite (U-Th)/He ages increase with distance from the coast and with elevation. However, these patterns are discontinued by samples of younger ages as a result of the reactivation process of pre-existing structures in the Brazilian continental margin. The total estimated denudation range from 1.2 to 2.8 km. The erosion rates range from 15.2 to 35.3 m/My. Thus, the multi-episodic thermal events, which led to the formation of important regional tectonic and geomorphological features (Mantiqueira Mountains, Serra do Mar Mountains, grabens, and sedimentary basins), seem to play a fundamental role in the evolution of the Brazilian continental margin. The records can be found in the thermal history of rocks and its correlated deposits in the continental margin.

A evolução da margem continental do sudeste do Brasil tem sido discutida por diversos autores desde meados do século passado até os dias atuais, especialmente no contexto da origem e evolução dos escarpamentos e das bacias tafrogênicas. Buscou-se contribuir com novos dados sobre a evolução da área a partir da aplicação da termocronologia de baixa temperatura (U-Th)/He em apatita, que oferece uma sensibilidade significativa para registrar movimentações tectônicas na crosta superior. Foi possível obter idades em 107 cristais de apatita de 18 amostras do embasamento coletadas no perfil com orientação NW-SE, numa seção entre a Serra da Mantiqueira e o Gráben da Guanabara. As idades corrigidas variam entre 250,1 8,7 Ma e 43,5 1,9 Ma (2 σ) e as não corrigidas entre 174,13 3,03 Ma e 27,07 0,60 Ma (1 σ). O Neocretáceo, o Eocretáceo e o Paleoceno são os principais registros no conjunto de dados, em ordem de importância. No Neocretáceo, o intervalo entre 83,6 e 72,1 Ma (Campaniano) representa o maior destaque nos registros termocronológicos, embora os outros registros (Maastrichtiano e Santoniano) também estejam presentes e sejam importantes. As idades do Neocretáceo destacam a importância dos eventos tectonomagmáticos e soerguimento regional na história térmica dessa área, inclusive com idades (~86 Ma) atribuídas ao contexto de soerguimento da Serra do Mar. As idades do Eocretáceo indicam o registro de eventos térmicos mais antigos, vinculados à evolução pré-rifte. Já os dados do Paleoceno estariam associados ao evento de reativação responsável pela implantação do sistema de riftes continentais (~65 Ma) e as idades do Eoceno, restritas à borda de falha da bacia de Resende (49,7 Ma e 43,5 Ma), à reativação do sistema de riftes nessa área. A dispersão de idades foi interpretada como efeito dos danos de radiação já que muitos grãos apresentam correlação entre idade e concentração de urânio (eU). Os padrões de tempo-temperatura (t-T), definidos a partir dos modelos HeFTy calibrados para o modelo de difusão que considera os efeitos de danos de radiação nos cristais, registraram eventos de resfriamento rápido, os quais mostram correlação direta com episódios de reativação e soerguimento na margem continental e com registros nas bacias continentais e marginais. O padrão de aumento das idades com a elevação, assim como da costa em direção ao interior é observado, mas mostra-se alterado pela ocorrência de idades mais jovens associadas à complexa evolução dessa margem continental com desnivelamentos de blocos vinculados à tectônica pós-rift, numa situação que ressalta a influência dos episódios de reativação. As estimativas de denudação total variam entre 1,2 e 2,8 km. As taxas de erosão variam entre 15,2 e 35,3 m/Ma. A evolução da área indica não apenas a influência de um evento específico mas, possivelmente, uma combinação de episódios que se alternaram e/ou atuaram em conjunto em determinados períodos. Os eventos de reativação mais antigos, combinados com os mais recentes, exibem os seus remanescentes na paisagem (serras da Mantiqueira e do Mar e os grábens e bacias sedimentares) e assumem papel fundamental na evolução da área. Os registros de tais episódios podem ser observados nas histórias térmicas das rochas e nos depósitos correlativos nas bacias sedimentares marginais e intracontinentais. / This doctoral dissertation involves low-temperature thermochronologic investigations to constrain the Mesozoic and Cenozoic tectonic reactivation of the continental margin of southeast Brazil. The study area is located in a segment of the Neoproterozoic Ribeira belt in southeastern Brazil, which occupied a central position in Western Gondwana. Lately, during the Mesozoic and Cenozoic, fault zones related to the development of the continental rifts in southeast Brazil reactivated. Using apatite (U-Th)/He thermochronology (AHe), we have presented the results of analysis on 107 apatite crystals of basement samples collected from a NWSE transect in the Mantiqueira Mountains to the Guanabara Graben, as well as from the NESE transverse faults. The data range from 27.07 0.60 Ma to 174.13 3.03 Ma (1 σ) for uncorrected ages, and from 43.5 1.9 Ma to 250.1 8.7 Ma (2 σ) for corrected ages. The Neo-Cretaceous, Eo-Cretaceous, and Paleocene are the main recorded AHe ages, in order of importance. The Eo-Cretaceous ages indicate the occurrence of older thermal events related to a pre-rifting phase (~121 Ma). The Neo-Cretaceous ages signify the importance of tectonic and magmatic events, and regional uplifting for the thermal history of the study area, including ages related to the Serra do Mar Mountains uplift (~86 Ma). Paleocene ages seem to be related to the reactivation (~65 Ma), which was responsible for the continental rifts in the southeastern Brazil. Finally, the Eocene ages (49.7 Ma and 43.5 Ma), which are from samples restricted to the Resende Basin border faults, indicate a continental rift reactivation. We investigated the age dispersion data, which were interpreted as an effect of radiation damage. Several samples show correlations between apatite (U-Th)/He age and effective U concentration (eU). We have applied HeFTy thermal modeling to obtain timetemperature (t T) paths using a radiation damage diffusion model. Inverse modeling of (U-Th)/He age data suggests rapid cooling episodes for all samples. The main thermal events recorded by the HeFTy models show a direct correlation with the timing of regional tectonic events: reactivation phases, continental margin uplift, and the sedimentary record. Apatite (U-Th)/He ages increase with distance from the coast and with elevation. However, these patterns are discontinued by samples of younger ages as a result of the reactivation process of pre-existing structures in the Brazilian continental margin. The total estimated denudation range from 1.2 to 2.8 km. The erosion rates range from 15.2 to 35.3 m/My. Thus, the multi-episodic thermal events, which led to the formation of important regional tectonic and geomorphological features (Mantiqueira Mountains, Serra do Mar Mountains, grabens, and sedimentary basins), seem to play a fundamental role in the evolution of the Brazilian continental margin. The records can be found in the thermal history of rocks and its correlated deposits in the continental margin.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study concerning the lifelong dynamic of undifferentiated cell populations present in the organism expanded the therapeutics frontiers aiming to healing several kinds of wounds and diseases. Different cell populations have been used for this purpose, as those derived from pre-implantation embryos, called embryonic stem cells (ESC); those derived from pluripotent somatic cells niches, responsible for organic regeneration throughout life, named adult stem cells (ASC); and cells derived from the bone marrow mononuclear fraction (BMNC), which has ASC and hematopoietic lineage cells at different stages of differentiation. Important barriers have been overcome aiming to elucidate benefits and risks inherent to cell therapy. However, the knowledge derives from an evolution process fraught with doubts, and there are many things to be unveiled for safe exploration of different kinds of cell therapy, mainly when allogeneic cells are used. Toxoplasmosis is an opportunistic zoonosis caused by the protozoan Toxoplasma gondii, which has a worldwide distribution and affects about a third of the human population. In the acute infection, T. gondii tachyzoites spread up and multiply themselves into host cells. Immune response leads to evasion of the protozoan in tissue cysts of (semi-latent) bradyzoites, mantaining the chronic infection of the host. Immunosuppression, as used in conditioning for allogeneic cells transplantation, is a risk factor for toxoplasmosis reactivation in chronically infected hosts. The studies presented in this thesis were performed aiming to contribute with: a. methods used for molecular detection of allogeneic cells after systemic transplantation by endovenous injection, allowing to mapping the organic distribution and the fate of these cells in recipient body; and b. understanding about interrelationships among conditioning (pharmacological immunosuppression) for transplantation, allogeneic cell therapy with BMNC and toxoplasmosis reactivation in chronically infected hosts. The study described in the Chapter 1 shows a nested-PCR test with increased sensitivity and assurance for molecular diagnosis of presence or absence of male mice cells in body fluids and tissues of female recipients after intravenous transplantation. This method, based on detection of specific DNA fragment from the Y chromosome, was effective for cells from two distinct populations: BMNC and in vitro cultured cells derived from adipose tissue. Therefore, this method can be suitable for other cell types. The study presented in the Chapter 2 shows the effects caused by an immunosuppressive pharmacological regimen with high doses of busulfan and cyclophosphamide (PCT), followed by allogeneic BMNC transplantation in a model of chronic toxoplasmosis in mice. This study was divided in three subsequent steps: I. experimental infection with type II cystogenic strain of T. gondii (ME-49) and characterization of acute and chronic toxoplasmosis; II. evaluation of the pharmacological immunosuppression effects in female Balb/c; and III. evaluation of the effects resulting from transplantation of male mice BMNC to recipient females. The pharmacological immunosuppression caused worsening of the general clinical condition of the animals and high mortality rates. This effect occurred remarkably earlier in animals chronically infected with T. gondii, showing the high risk of the combination between persistent toxoplasmosis and pharmacological immunosuppression in conditioning for allogeneic transplantation. This study showed the safety of the allogeneic BMNC transplantation in female Balb/c independently of the infection by T. gondii, provided that they have not been subjected to conditioning regimen before transplantation. In the Chapter 3, a pharmacological immunosuppressive regimen, with reduced doses of busulfan and cyclophosphamide (PCTrd), was tested as an alternative to minimize conditioning regimen inherent risks in mice chronically infected with T. gondii and submitted to allogeneic transplantation of BMNC. This study was also divided in three sequential steps: I. oral infection of female Balb/c with tissue cysts of T. gondii (cystogenic VEG strain) and monitoring over a 120 days period (chronic toxoplasmosis); II. evaluation of conditioning regimen effects using reduced doses of busulfan and cyclophosphamide (PCTrd); III. endovenous transplantation of allogeneic BMNC from male donors to the female Balb/c. The results showed the safety of the PCTrd for use in female Balb/c chronically infected with T. gondii. Reduced doses of busulfan and cyclophosphamide (PCTrd) resulted in lower incidence and intensity of clinical signs and absence of mortality, in contrast to results that were observed with high doses (PCT) recommended for myeloablation. Transplantation of allogeneic bone marrow-derived mononuclear cells from male donors was safe in the short term for female Balb/c mice submitted to PCTrd regardless of persistent infection by T. gondii. / O estudo da dinâmica das populações celulares indiferenciadas, presentes no organismo ao longo da vida, ampliou a fronteira de alternativas para o tratamento de vários tipos de lesões e de doenças. Diversas populações celulares têm sido usadas para isso, como as derivadas de embriões em fase de pré-implantação, denominadas células-tronco embrionárias (CTE); as derivadas de nichos de células somáticas pluripotentes, responsáveis pela regeneração dos tecidos orgânicos ao longo da vida, chamadas de células-tronco adultas (CTA); e as células da fração mononuclear da medula óssea (CFMO), que conta com CTA e células da linhagem hematopoiética em variados estágios de diferenciação. Importantes obstáculos têm sido superados no que se refere ao conhecimento de benefícios e de riscos inerentes à terapia celular. Contudo, a construção do conhecimento é permeada de dúvidas e há muito a ser desvendado para que se possam explorar com segurança as potencialidades das terapias celulares, especialmente usando células alogênicas. A toxoplasmose é uma zoonose oportunista causada pelo protozoário Toxoplasma gondii, que apresenta distribuição mundial e acomete cerca de um terço da população humana. Na fase aguda da infecção, taquizoítos de T. gondii disseminam-se e multiplicam-se nas células hospedeiras. A resposta imune induz a evasão do protozoário em cistos teciduais de bradizoítos (forma de semilatência), mantendo o hospedeiro cronicamente infectado. A imunossupressão, como a utilizada no pré-condicionamento para transplante de células alogênicas, é um fator de risco de reativação da toxoplasmose em portadores crônicos. Na presente tese, são apresentados estudos realizados com objetivo de contribuir com: a. métodos de detecção molecular de células alogênicas após o transplante sistêmico pela via endovenosa, permitindo o mapeamento da distribuição e do destino destas células no organismo receptor; e b. compreensão das inter-relações envolvendo pré-condicionamento (imunossupressão farmacológica) para o transplante, terapia celular alogênica com CFMO e reativação da toxoplasmose em portadores crônicos. No Capítulo 1 demonstra-se uma nested-PCR que aumenta a sensibilidade e a segurança do diagnóstico molecular de presença ou ausência de células de camundongos machos em fluidos e tecidos de receptoras fêmeas após transplante endovenoso. O método, que envolve a detecção de fragmento de DNA específico do cromossomo Y, foi eficaz para células de duas populações distintas: CFMO e células cultivadas in vitro derivadas do tecido adiposo. Portanto, o método pode ser útil para outros tipos celulares. O estudo apresentado no Capítulo 2 demonstra os efeitos de um protocolo de imunossupressão farmacológica com altas doses de busulfan e ciclofosfamida (PCT), seguido do transplante alogênico de CFMO em um modelo de toxoplasmose crônica em camundongos. Esse estudo foi dividido em três etapas subsequentes: I. infecção experimental com cepa cistogênica do tipo II de T. gondii (ME-49) e caracterização da toxoplasmose aguda e crônica; II. avaliação dos efeitos da imunossupressão farmacológica nas fêmeas Balb/c; e III. avaliação dos efeitos do transplante de CFMO de camundongos machos para as fêmeas receptoras. A imunossupressão farmacológica provocou agravamento do quadro clínico geral dos animais e altas taxas de mortalidade. Esse efeito foi notavelmente precoce nos animais cronicamente infectados por T. gondii, demonstrando o alto risco da combinação entre toxoplasmose persistente e imunossupressão farmacológica na preparação para o transplante alogênico. Demonstrou-se a segurança do transplante alogênico de CFMO em fêmeas Balb/c infectadas ou livres de infecção por T. gondii, desde que não tenham sido submetidas ao protocolo de pré-condicionamento para o transplante. No Capítulo 3, um regime de imunossupressão farmacológica com doses reduzidas de busulfan e ciclofosfamida (PCTdr) foi testado como alternativa para minimizar os riscos inerentes ao pré-condicionamento em camundongos cronicamente infectados com T. gondii e submetidos ao transplante alogênico de CFMO. Esse estudo também foi dividido em três etapas sequenciais: I. infecção oral de fêmeas Balb/c com cistos teciduais de T. gondii (cepa VEG, cistogênica) e monitoramento durante um período de 120 dias (toxoplasmose crônica); II. avaliação dos efeitos do regime de pré-condicionamento, com doses reduzidas de busulfan e ciclofosfamida (PCTdr); III. transplante alogênico endovenoso de CFMO de doadores machos para as fêmeas Balb/c. Os resultados demonstraram a segurança do PCTdr para uso em Balb/c fêmeas cronicamente infectadas com T. gondii. Doses reduzidas de busulfan e ciclofosfamida (PCTdr) resultaram em menor incidência e intensidade de sinais clínicos e ausência de mortalidade, em oposição ao ocorrido com as altas doses (PCT) recomendadas para mieloablação. O transplante alogênico de células mononucleares da medula óssea de doadores machos foi seguro no curto prazo em fêmeas Balb/c submetidas ao PCTdr, independentemente de infecção persistente pelo T. gondii.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed at reproducting and characterizing the virological and clinico-pathological aspects of acute and latent genital infection by bovine herpesvirus type 1.2 (BoHV-1.2) in heifers. Four heifers were inoculated intravaginally with a Brazilian BoHV-1.2 isolate (SV-56/90) recovered from an outbreak of balanoposthitis. Virus inoculation (108.1TCID50/animal) resulted in efficient virus replication in the genital mucosa and the development of moderate to severe vulvovaginitis. The inoculated heifers shed virus in genital secretions in titers up to 107.3TCID50/mL until day 10 post infection (pi). Hyperemia, edema of vulvar and vestibular mucosa, vesicles, pustules and scabs were observed between days 1 and 10 pi. The vesicles and pustules increased in size and eventually coalesced and became covered with a mucopurulent and fibrinous exsudate. These signs increased in severity up to days 5 8 pi and progressively subsided thereafter. Dexamethasone administration at day 55 pi resulted in virus shedding in vaginal secretions of all heifers for up to 10 days. Virus reactivation was accompanied by genital signs resembling those observed during acute infection, yet less severe. Examination of the lumbar sacral ganglia and lymph nodes by PCR at day 36 postreactivation revealed the presence of latent viral DNA in the pudendal (4/4), genito-femoral, sciatic and rectal caudal (3/4) and obturator nerve ganglia (1/4); and in the sacral (3/4), deep inguinal, pre femoral, supramammary (2/4) and medial iliac lymph nodes (1/4). These results demonstrate that BoHV-1.2 DNA persists in sacral ganglia and regional lymph nodes during latency, and help in understanding the pathogenesis of acute and latent genital infection by BoHV-1.2. / O presente estudo teve como objetivos reproduzir e caracterizar os aspectos virológicos e clinico-patológicos da infecção genital aguda e latente pelo herpesvírus bovino tipo 1.2 (BoHV-1.2) em bezerras. Quatro bezerras foram inoculadas no trato genital com um isolado brasileiro de BoHV-1.2 (SV-56/90) oriundo de um surto de balanopostite. A inoculação do vírus (108,1TCID50/animal) resultou em replicação viral eficiente na mucosa genital e no desenvolvimento de vulvovaginite moderada a severa. As bezerras inoculadas excretaram vírus nas secreções genitais em títulos de até 107,3TCID50/mL por até 10 dias pós-inoculação (pi). Hiperemia, edema das mucosas vulvar e vestibular, vesículas, pústulas e crostas foram observados entre os dias 1° e 10° dia pi. As vesículas e pústulas aumentaram de diâmetro, eventualmente coalesceram e tornaram-se recobertas com um exsudato mucopurulento e fibrinoso. Os sinais aumentaram em severidade do 5° ao 8° dia pi e regrediram a partir de então. Administração de dexametasona dia 55 pi resultou em excreção viral nas secreções vaginais por até 10 dias. A reativação viral foi acompanhada de sinais genitais semelhantes aos observados durante a infecção aguda, porém com menor severidade. A análise dos gânglios lombo-sacral e linfonodos regionais por PCR no dia 36 pós-reativação demonstrou a presença de DNA viral latente nos gânglios pudendo (4/4), genito-femural, ciático, retalcaudal (3/4) e obturador (1/4); e nos linfonodos sacral (3/4), inguinal profundo, pré-femural, supramamário (2/4) e ilíaco medial (1/4). Esses resultados demonstram que o DNA do BoHV-1.2 persiste nos gânglios sacrais e em linfonodos regionais durante a latência, e contribuem para o conhecimento da patogenia da infecção genital aguda e latente pelo BoHV-1.2.

A soja vem ganhando destaque, pois alguns estudos apontam uma série de potenciais benefícios para a saúde. Estão presentes na soja dois grupos de inibidores de proteases. Alguns estudos demonstram que o tratamento térmico pode não ser suficiente para a inativação completa desses inibidores. Esses inibidores podem afetar a digestibilidade da proteína e a absorção e biodisponibilidade de alguns minerais, como o ferro. Realizaram-se cinco tratamentos: T1 e T2 – com secagem prévia + 10 e 15 minutos de forno, respectivamente; T3, T4 e T5 – sem secagem prévia + 45, 50 e 60 minutos de forno. O controle foi seco em estufa (55ºC) durante 31 horas. A quantidade de ferro nas amostras analisadas variou de 83,67 a 58,8 mg/kg e a porcentagem de ferro dialisado foi de 0,95% a 1,38%, estando de acordo com o encontrado na literatura. Os valores da digestibilidade da proteína in vitro variaram de 91,21% a 93,14%, sem que houvesse correlação com os inibidores de tripsina, sendo a melhora da digestibilidade devida ao tratamento térmico. A atividade dos inibidores de tripsina para os tratamentos com secagem prévia variou de 25,24 a 23,94 UTI/mg de proteína e para os sem secagem prévia de 46,39 a 38,33 UTI/mg de proteína. A atividade dos inibidores para o controle foi de 55,81 UTI/mg de proteína. Os valores estão de acordo com a literatura, sendo, portanto, considerados como adequados, mostrando que a tostagem em forno convencional é bastante eficaz quanto à inativação do inibidor de tripsina. Após a proteólise in vitro, verificou-se reativação dos inibidores de tripsina em todos os tratamentos analisados. Os valores variaram de 5,48 UTI/mg de proteína (controle) a 7,65 UTI/mg de proteína (T1). As maiores porcentagens foram para os tratamentos com secagem prévia, 30,31% e 28,45%, enquanto que para os sem secagem prévia foi de 14,68%, 14,12% e 19,38%. O controle apresentou 9,82% de reativação. Concluiu-se que a tostagem em forno convencional inativou os inibidores de tripsina, sendo o tratamento sem secagem prévia o mais eficaz, pois, com esse tratamento, houve menor reativação dos inibidores após a proteólise in vitro. A tostagem foi responsável pela melhora da digestibilidade da proteína e da diálise de ferro in vitro. O tratamento que promoveu a maior aceitabilidade dos grãos de soja tostados foi o que recebeu o tempo intermediário de 50 minutos, sem secagem prévia. / The soy comes gaining prominence, therefore some studies point a series of potential benefits with respect to the health. Two groups of inhibitors of proteases are present in the soy. Some studies demonstrate that the thermal treatment can not be enough for the complete inactivation of these inhibitors. These inhibitors can affect the digestibility of the protein and the absorption and availability of some minerals, as the iron. Five treatments had been do: T1 and T2 - with previous drying + 10 and 15 minutes of oven, respectively; T3, T4 and T5 - without previous drying + 45, 50 and 60 minutes of oven. The control was dry in oven (55ºC) during 31 hours. The amount of iron in the analyzed samples varied of 58,8 the 83,67 mg/kg and percentage of dialysed iron was of 0,95% the 1.38%, being in accordance with the found one in literature. The values of the digestibility of protein in vitro had varied of 91,21% the 93.14%, without that it had correlation with trypsin inhibitors, being the improvement of the digestibility due to the thermal treatment. The trypsin inhibitors activity for the treatments with previous drying varied of 25,24 the 23,94 UTI/mg of protein and for the ones without previous drying varied of 38,33 the 46,39 UTI/mg of protein. The inhibitors activity for the control was of 55,81 UTI/mg of protein. The values are according with the literature, being, therefore, considered as adjusted, showing that the roasting in conventional oven is sufficiently efficient how much to the inactivation of trypsin inhibitors. After proteolysis in vitro, verified reactivation of trypsin inhibitors in all the analyzed treatments. The values had varied of 5,48 UTI/mg of protein (control) the 7,65 UTI/mg of protein (T1). The biggest percentages had been for the treatments with previous drying, 30.31% and 28.45%, while that for the ones without previous drying it was of 14,68%, 14.12% and 19,38%. The control presented 9.82% of reactivation. The treatment the most efficient without previous drying was concluded that the roasting in conventional oven inactivated trypsin inhibitors, being, therefore, with this treatment, proteolysis had minor after reactivation of inhibitors in vitro. The roasting was responsible for the improvement of the digestibility of protein and dialyse of the iron in vitro. The treatment that promoted the biggest acceptability of the roasted grains of soy was what it received the time intermediate from 50 minutes, without previous drying.