L'utilisation de fluides au comportement rhéologique complexe (seuil d'écoulement, thixotropie) est de plus en plus courante dans notre quotidien. Une description globale du comportement n'est pas suffisante et c'est pourquoi ce travail se focalise sur la détermination locale des propriétés de ces matériaux complexes. Pour cela nous nous appuyons sur des méthodes optiques pour obtenir des informations sur la contrainte et la vitesse de cisaillement. Nous avons choisi d'opter pour la PIV (Particle Image Velocimetry) pour l'obtention du gradient de vitesse et la photoélasticimétrie pour la mesure de contrainte. L'emploi de ces deux techniques de mesure oblige que les fluides étudiés soient transparents et biréfringents. Nous étudions alors une solution de Milling Yellow (fluide au comportement rhéologique simple) pour valider nos techniques de mesure et des suspensions de Laponite qui sont des fluides à seuil et thixotropes. La première étape de ce travail consiste à avoir une idée générale du comportement rhéologique des fluides d'où leur caractérisation à l'aide d'un rhéomètre. Ensuite, dans une géométrie où la répartition de contrainte est connue (géométrie à cylindres coaxiaux), nous déterminons les lois rhéo-optiques nous permettant de relier la contrainte dans le matériau à sa réponse optique. Enfin, dans une géométrie plan-plan, nous couplons les deux techniques de mesure optiques (PIV et photoélasticimétrie) afin de reconstruire un rhéogramme local des différents fluides étudiés pouvant être comparé à celui issu de mesures classiques de rhéométrie. / The use of fluids with a complex rheological behavior (yield stress, thixotropy) is becoming more common in our daily lives. However, a global description of this behavior is not satisfactory even if it is quickly and easily accessible. The aim of this work is to advance in the understanding of complex behaviors at a local scale. Optical methods are the best way to do that. In our case, we need to get information about the shear stress and the shear rate. So we need a measurement technique for each of these variables. A PIV (Particle Image Velocimetry) technique is used to obtain the shear rate and the shear stress is determined by photoelasticimetry. The use of these two techniques requires that the studied fluids are transparent and birefringent. Then, our measurement techniques are validated using a Milling Yellow solution (a simple rheological fluid) before studying Laponite suspensions which are thixotropic yield stress fluids. Firstly, a rheometer is used to have a general idea of the rheological behavior of our fluids. Secondly, in a geometry where the shear stress distribution is known (a coaxial cylinders geometry), rheo-optical laws connecting the shear stress within the material to its optical response are determined. Finally, in a plate-plate geometry, the two optical measurement techniques (PIV and photoelasticimetry) are coupled to reconstruct a local rheogram for the studied fluids that can be compared to the one obtained from conventional Rheometric measurements.

O risco de transmissão placentária para o feto, associados à susceptibilidade de neuroinvasão pelo vírus 17D levaram à recomendação de que a vacina contra febre amarela (FA) não fosse administrada durante a gravidez. Pretendeu-se avaliar o efeito desta no desempenho gestacional de camundongos prenhes. Os resultados mostraram decréscimo na viabilidade fetal causado pela vacinação. Reatividade ao antígeno da FA foi observada nos tecidos hepáticos maternos e de fetos vivos. Na placenta, o antígeno viral não foi observado na barreira materno-fetal. Nos fetos natimortos e em reabsorção, esta passagem pareceu mais acentuada; reatividade foi observada em diversos órgãos. O antígeno viral foi detectado em todas as regiões placentárias. A detecção de RNA viral nas amostras indica que há atividade viral nos tecidos fetais. Nossos achados indicam que há fases gestacionais mais susceptíveis à infecção viral vacinal e que podem determinar perdas fetais. A presença do antígeno e de atividade viral no fígado fetal sugere que o vírus vacinal é transmitido da mãe para o feto. / The risk of placental transmission to the fetus, associated with susceptibility to neuroinvasion of the 17D virus led to the recommendation that the vaccine against yellow fever (YF) was not administered during pregnancy. Intended to evaluate the effect of the vaccine in gestational performance of pregnant mice. The results showed a decrease in fetal viability caused by vaccination. Antigen reactivity of YF was observed in maternal and live fetuses liver tissue. In the placenta, the viral antigen was not observed in maternal-fetal barrier. In the stillborn fetuses and resorption, this passage seemed more pronounced; reactivity was observed in several organs. The viral antigen was detected in all placental regions. The detection of viral RNA in the samples indicates that there is viral activity in fetal tissues. Our findings indicate that there are stages of pregnancy more susceptible to viral vaccine infection that could determine fetal loss. The presence of the antigen and viral activity in fetal liver suggests that the vaccine virus is transmitted from mother to fetus.

A computer simulation model was developed to examine the effects of various levels of alewife densities, harvest, and bycatch rates on yellow perch Perca flavescens relative densities in Indiana waters of Lake Michigan. The model utilized STELLA® Research software to develop the age-structured population model to include measured or predicted biological characteristics of density-dependent growth, recruitment, and mortality.The model was validated by simulating historically documented yellow perch catch per unit effort (CPUE) from 1984 - 1998. A strong linear relationship (R2= 0.70) between the model predicted CPUE values and the actual CPUE values was found. Twenty year model projections were performed using 1998 yellow perch trawl CPUE as starting values. Alewife abundance was established as either constantly high, constantly low, or allowed to fluctuate randomly and forecasts made used the average of 100 runs. Harvest was imposed on the yellow perch population at 20, 40, and 60% rate levels for fish >_ 200 mm coupled with bycatch at20, 40 and 60% rate levels for fish ranging from 165 - 200 mm.Alewife abundance was the major factor determining the relative abundance of the yellow perch population. On average, constantly high alewife abundance with no harvest or bycatch resulted in projected continuing suppression of yellow perch abundance from 1998 levels. The model predicted the population to rebound using constant low and random alewife abundance with no harvest or bycatch to approximately 1,100 fish/h and 700 fish/h, respectively.The model revealed harvest to have a generally negative impact on the yellow perch population. Increasing harvest and bycatch rate levels resulted in the suppression of projected increases in yellow perch relative abundance. Additionally, increasing harvest and bycatch rates resulted in greater predicted declines in yellow perch abundance. / Department of Biology

Metal-contamination of lakes simplifies food webs and reduces the efficiency of energy transfer to top trophic organisms, such as yellow perch (Perca flavescens). Benthic invertebrate community composition and yellow perch diet, growth and activity levels from lakes along a metal-contamination gradient were used to assess the importance of a naturally diverse prey base for maintaining energy transfer to growing fish, and how this is disrupted by metal-contamination. As perch grow larger, they shift their diet to larger prey; otherwise, the activity costs of foraging for many, small prey, instead of a few large prey, become too high and the fish stop growing. Metal contaminated lakes have less diverse zoobenthic communities, particularly the lack of large bodied invertebrate taxa, forcing perch to rely on smaller benthic prey. Perch from metal-contaminated lakes display slow growth and poor condition during benthivory. Estimates of fish activity, using the activity of the glycolytic enzyme Lactate dehydrogenase in perch white muscle tissue as a proxy, suggest that diet shifts to larger prey lower activity costs and may explain how diet shifts maintain growth efficiency as perch grow larger. Perch from metal-contaminated lakes cannot benefit from the energetic advantages of switching to larger prey and thus exhibit poor growth.

Thesis--Université de Paris Sud, Centre d'Orsay, 1977. / Summary in French and English. Includes bibliographical references (p. 225-228).

La filière OLED (diode électroluminescente organique) est depuis quelques annéesfortement industrialisée notamment depuis leur utilisation dans les smartphones et les téléviseurs.Cependant, les procédés de fabrication, notamment l’évaporation thermique sous vide, restent coûteuxet ne peuvent pas être utilisés pour développer des applications à faible valeur ajoutée (petitsafficheurs, signalétique, éclairage). Ces travaux de thèse ont pour objectif de développer une OLEDperformante et stable fabriquée à coût réduit afin de répondre à cette problématique. La voie liquide aété privilégiée afin de diminuer les coûts de fabrication de l’OLED et il a été choisi de développer unestructure inverse pour améliorer la stabilité. Dans ce travail de thèse, le polymère PEIE(polyéthylénimine éthoxylate) a été utilisé pour diminuer le travail de sortie de la cathode transparente.Nous avons montré qu’il était possible d’atteindre des performances supérieures en structure inversequ’en structure conventionnelle à partir du même polymère émissif, le Super Yellow. Afin desimplifier le procédé de dépôt, nous avons montré qu’un mélange binaire {PEIE et matériau bloqueurde trous} pouvait être déposé en une seule fois tout en conservant un fonctionnement optimal. Uneétude par TOF-SIMS (Spectrométrie de Masse d’Ions Secondaires à Temps de Vol) a permis de mettreen évidence une ségrégation verticale du mélange binaire. Par ailleurs, l’électrode en oxyde d’étainindium(ITO), qui représente généralement plus d’un quart du coût de fabrication, a été remplacéeavec succès par une électrode de SnO2 (oxyde d’étain), déposée par ALD (dépôt de couches mincesatomiques). / OLED (Organic Light-Emitting Diode) technology has been exploited on an industrialscale for several years, principally in smartphones, TV displays, and similar devices. However, currentfabrication processes, such as thermal evaporation under high vacuum, are expensive and cannot beused for low-cost applications (signage, lighting, etc.). This work aims to develop high-performance,stable, low-cost OLEDs. Fabrication by solution processing was chosen to reduce the processing costsin any future commercialization of the work, while the inverted architecture was used to optimizedevice stability. In this work, ethoxylated polyethylenimine (PEIE) was used to reduce the workfunction of the transparent cathode. It was shown that higher performances could be obtained withinverted OLEDs compared to direct devices incorporating the same emissive polymer (Super Yellow).Furthermore, it was demonstrated that a binary blend, (PEIE and a hole blocking material) could bedeposited in a single step without reducing the OLED device’s performance – greatly simplifying thefabrication process. A TOF-SIMS (Time of Flight-Secondary Ion Mass Spectrometry) study wasconducted which demonstrated a vertical phase segregation of the binary blend. Finally, the indiumtinoxide (ITO) electrode, which represents at least 25% of the fabrication cost, was successfullyreplaced with a tin oxide (SnO2) layer, deposited by ALD (Atomic Layer Deposition).

Orientador: Cristina de Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-22T20:46:44Z (GMT). No. of bitstreams: 1 HernandezTasco_Aleidys_M.pdf: 2499047 bytes, checksum: 236f6901a7068d237ee969ad03880acc (MD5) Previous issue date: 2013 / Resumo: Em 1927 a luta contra a febre amarela parecia finalizada no continente americano. A Fundação Rockefeller, instituição filantrópica estadunidense que tinha como principal objetivo o combate da febre amarela na primeira metade do século XX, assegurava que a doença estava quase erradicada. No entanto, a ocorrência das epidemias de febre amarela no Rio de Janeiro em 1928 (Brasil) e em Socorro em 1929 (Colômbia), colocou em dúvida as medidas profiláticas recomendadas e aplicadas tanto pelos órgãos nacionais de Saúde Pública como os da Fundação Rockefeller que participou da luta contra essa doença em ambos os países. Ao mesmo tempo em que ocorriam as epidemias, uma controvérsia instalou-se em torno à descoberta de Stokes, Bauer e Hudson na África, em 1927, que demonstrou que a febre amarela era facilmente inoculável no Macacus Rhesus. Tal descoberta acabou por rejeitar a concepção etiológica estabelecida em 1919 por Noguchi. A nova descoberta dos pesquisadores, as epidemias e a rejeição da teoria de Noguchi geraram uma enorme desconfiança na época, dando a sensação de que nada era seguro em assuntos relacionados à febre amarela, despertando uma crise nos estudos da doença. Esta pesquisa assume a responsabilidade de fazer um estudo comparativo a partir da ciência, da política e da técnica que ambos os países usaram no combate à doença, com intuito de conhecer as experiências desenvolvidas com o fenômeno da febre amarela. Assim, a dissertação tem dois objetivos principais. Primeiro, analisar o processo histórico da febre amarela, a fim de entender a crise que predominou nos estudos da doença entre os anos de 1927 e 1930. Para isso iremos analisar os múltiplos atores locais, nacionais e internacionais no domínio teórico e técnico da doença, durante a epidemia de febre amarela no Rio de Janeiro, em 1928-29, e em Socorro, em 1929. O segundo objetivo é analisar as manifestações científicas contra o avanço da febre amarela no Brasil e na Colômbia, a partir das duas últimas grandes epidemias registradas no Rio de Janeiro (1928-1929) e em Socorro (1929), através das tensões entre o ideal de uma ciência médica universal, representada pela Fundação Rockefeller e pelas Conferências Pan-Americanas, e as práticas de saúde pública, representadas por médicos e pesquisadores, elaboradas localmente para minimizar o alcance da febre amarela no período de 1930 a 1948 / Abstract: In 1927 the fight against yellow fever seemed to have concluded in American continent. In the first half of the twentieth century, a philanthropic American organization had as primary goal the fight against that outbreak (The Rockefeller Foundation) and, they ensured that epidemic was almost completely eradicated in that time. Nonetheless, two yellow fever outbreaks recorded in Rio de Janeiro in 1928 (Brazil) and Socorro in 1929 (Colombia) put in doubt the prophylactic measures recommended and implemented by the National Agencies of Public Health and the Rockefeller Foundation. This later institution took part in the fight against the disease in both countries. A controversy was established, while those epidemics took place in both countries, due to the discovery made by Stokes, Bauer e Hudson in Africa in 1927, which demonstrated Macacus Rhesus could be easily inoculated with the virus of yellow fever. That discovery eventually rejected the etiological agent theory established by Noguchi in 1919. In this fashion, with the new discovery, the epidemics and the rejecting of Noguchi's theory, a huge distrust grew up in those days, giving the impression that nothing was safe in issues related to yellow fever, and generating a crisis in studies of disease. Therefore, a comparative study from science, policy and technical that both Colombia and Brazil used in fighting against disease is carried out in this research in order to know the experiences developed with the yellow fever. In this manner, this dissertation has two mains objectives. First, the historical process of yellow fever will be analyzed by this research to understand the crisis that prevailed in studies of that disease between 1927 and 1930. For this reason, the multiple local actors, national and international in theoretical and technical field of the disease were analyzed during yellow fever outbreak in 1928-29 in Rio de Janeiro and in 1929 in Socorro. Second, several scientific manifestations against the progress of yellow fever in Brazil and Colombia were also studied from the last two major epidemics recorded in Rio de Janeiro (1928-1929) and Socorro (1929). Thus, controversies between an ideal of universal medical science represented by Rockefeller Foundation and Pan-American Conference, and the local public health practices developed to minimize the propagation of yellow fever in the period between 1930 and 1948 / Mestrado / Politica Cientifica e Tecnologica / Mestra em Política Científica e Tecnológica

Le virus de la panachure jaune du riz (virus RYMV pour Rice Yellow Mottle Virus) infecte principalement le genre Oryza et provoque d'importants dégâts sur les cultures de riz en Afrique. Bien que son génome soit rudimentaire, ce virus code des protéines essentielles pour son maintien chez l’hôte en dépit des mécanismes de défense de la plante. Les travaux récents de l’équipe ont permis d’identifier la protéine P1 codée par ce virus comme une protéine qui pourrait, grâce à sa propriété de suppresseur de RNA silencing, permettre au virus de contourner un mécanisme de défense essentiel de l’hôte et permettre au virus de perpétuer son cycle viral. Peu de données concernant les mécanismes d’action de la protéine P1 sont disponibles à ce jour. Le travail entrepris au cours de ma thèse a donc consisté à compléter les connaissances sur la biochimie de cette protéine, à définir sa structure tridimensionnelle et à mettre à jour sa localisation sub cellulaire afin de révéler des propriétés qui pourraient nous permettre non seulement de mieux comprendre comment cette protéine opère ses fonctions mais également de définir des méthodes de lutte adéquates contre ce virus. Ainsi, je montre que la protéine P1 constitue une nouvelle famille de protéine à doigt de zinc possédant une structure 3D inédite composée d’un premier domaine impliqué dans la dimérisation de la protéine et dans des interactions avec des ligands dont certains pourraient provenir de la plante hôte. Mon travail permet également d’identifier un deuxième domaine senseur de l’état redox au sein de la protéine qui lui permet probablement de sonder l’état de la plante pendant l’infection virale et d’adapter ses conformations pour assurer ses fonctions. Finalement, une approche par mutagénèse sur la protéine P1 assistée par la nouvelle structure 3D démontre qu’il est désormais possible d’identifier les résidus essentiels à la protéine pour sa participation dans l’infection virale. Ce travail ouvre donc de nombreuses perspectives pour de futures études de mécanistique sur ces domaines-clé de la protéine, ainsi que pour des études sur sa diversité génétique au sein des très nombreux isolats du virus RYMV en Afrique. / The virus of rice yellow mottle virus (RYMV for Rice Yellow Mottle Virus) mainly infects the genus Oryza and causes significant damage to rice crops in Africa. Although its genome is rudimentary, this virus code essential proteins for its maintenance in the host despite the defense mechanisms of the plant. Recent work by the team has identified the P1 protein encoded by the virus as a protein that could, through its ownership of RNA silencing suppressor, allow the virus to bypass an essential defense mechanism of the host and allow the virus to perpetuate its viral cycle. Little data on the mechanisms of action of the P1 protein is available to date. The work undertaken during my thesis was therefore to supplement the knowledge of the biochemistry of this protein, to define its three-dimensional structure and update its sub cellular localization to reveal properties that could enable us not only to understand how this protein works its functions but also to define methods of adequate response against the virus. Thus, I show that the P1 protein is a new zinc finger protein family having a unique 3D structure consisting of a first domain involved in the dimerization of the protein and in interactions with ligands some of which may originate from the plant host. My work also identifies a second sensor field in the redox state of the protein that probably allows him to probe the state of the plant during viral infection and adapt its conformation to conduct their duties. Finally, a mutagenesis approach to P1 assisted by the new 3D protein structure shows that it is now possible to identify critical residues in the protein for its participation in the viral infection. This work thus opens up many possibilities for future mechanistic studies on these key areas of the protein, as well as for studies of genetic diversity within many RYMV isolates of virus in Africa

Orientadora: Profa. Dra. Poliana Cardoso-Gustavson / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biotecnociência, 2017. / As folhas são uma interface entre o organismo vegetal e o ambiente. Este órgão apresenta uma série de atributos que estão relacionados a funções especificas (caracteres foliares funcionais) e/ou mostram respostas ao estresse biótico e abiótico. O ozônio (O3) é um poluente fitotóxico que pode causar injúrias visíveis em plantas; tais injúrias auxiliam na identificação de potenciais riscos à vegetação. Os marcadores microscópicos destacam-se como única forma de validar essas injúrias como decorrentes de processos oxidativos provocados pelo O3. Embora a dissociação de O3 em espécies reativas de oxigênio (ROS) ocorra em meio aquoso, a influência de processos de liberação e posterior reabsorção de compostos hidrofílicos no uptake de ROS derivadas da dissociação do O3 é ainda desconhecido. Nesta dissertação, três hipóteses foram testadas: (1) o surgimento dos sintomas específicos de O3 segue o fluxo de entrada de água pelas lâminas foliares de cana-de-açúcar; (2) os tricomas não-glandulares de Croton floribundus a protegem dos efeitos nocivos do O3 ao prevenir a entrada deste gás nos tecidos foliares; (3) os nectários extraflorais de Astronium graveolens e Piptadenia gonoacantha são rotas de reabsorção de néctar contendo ROS nos tecidos foliares, tornando estas espécies mais vulneráveis aos efeitos do O3. Um modelo de uptake de ROS por meio de glândulas foi proposto e considerações acerca desta entrada em plantas C3 e C4 são apresentadas em dois capítulos independentes. / Leaves are interfaces between the whole organism and the environment. This organ displays a series of attributes that are linked to specific functions (functional leaf traits) and/or show responses to biotic and abiotic stress factor. Ozone (O3) is a phytotoxic pollutant that may cause visible injuries in plants. These injuries aid in the identification of potential risks to vegetation. Microscopic markers are highlight as the only tool to validate these injuries as consequences of oxidative processes caused by O3. Although the O3-dissociation into reactive oxygen species (ROS) occurs in an aqueous medium, the influence of releasing and reabsorption processes of hydrophilic compounds in the ROS-dissociated uptake is still unknown. In this dissertation, three hypotheses were tested: (1) the rising of O3-specific symptoms follows the water entrance flux through leaf tissues of sugarcane; (2) non-secretory trichomes of Croton floribundus protect this species against the adverse effects of O3; (3) extrafloral nectaries of Astronium graveolens and Piptadenia gonoacantha are routes of nectar reabsorption rich in ROS, turning these species more vulnerable to damage effects of O3. A new uptake model of ROS through glands was proposed and considerations about this entrance in C3 and C4 plants are presented in two independent chapters.

O risco de transmissão placentária para o feto, associados à susceptibilidade de neuroinvasão pelo vírus 17D levaram à recomendação de que a vacina contra febre amarela (FA) não fosse administrada durante a gravidez. Pretendeu-se avaliar o efeito desta no desempenho gestacional de camundongos prenhes. Os resultados mostraram decréscimo na viabilidade fetal causado pela vacinação. Reatividade ao antígeno da FA foi observada nos tecidos hepáticos maternos e de fetos vivos. Na placenta, o antígeno viral não foi observado na barreira materno-fetal. Nos fetos natimortos e em reabsorção, esta passagem pareceu mais acentuada; reatividade foi observada em diversos órgãos. O antígeno viral foi detectado em todas as regiões placentárias. A detecção de RNA viral nas amostras indica que há atividade viral nos tecidos fetais. Nossos achados indicam que há fases gestacionais mais susceptíveis à infecção viral vacinal e que podem determinar perdas fetais. A presença do antígeno e de atividade viral no fígado fetal sugere que o vírus vacinal é transmitido da mãe para o feto. / The risk of placental transmission to the fetus, associated with susceptibility to neuroinvasion of the 17D virus led to the recommendation that the vaccine against yellow fever (YF) was not administered during pregnancy. Intended to evaluate the effect of the vaccine in gestational performance of pregnant mice. The results showed a decrease in fetal viability caused by vaccination. Antigen reactivity of YF was observed in maternal and live fetuses liver tissue. In the placenta, the viral antigen was not observed in maternal-fetal barrier. In the stillborn fetuses and resorption, this passage seemed more pronounced; reactivity was observed in several organs. The viral antigen was detected in all placental regions. The detection of viral RNA in the samples indicates that there is viral activity in fetal tissues. Our findings indicate that there are stages of pregnancy more susceptible to viral vaccine infection that could determine fetal loss. The presence of the antigen and viral activity in fetal liver suggests that the vaccine virus is transmitted from mother to fetus.