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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
941

Étude théorique d'ondes de volume, localisées et de surface dans les cristaux phononiques granulaires / Propagative, localized and surface waves in granular phononic crystals

Pichard, Hélène 28 November 2014 (has links)
Ce travail de thèse porte sur l’étude de la propagation d’ondes de volume et d’ondes de surface dans des cristauxphononiques granulaires en régime linéaire. Différents aspects sont développés dans ce manuscrit. L’effet de la prise encompte des degrés de liberté en rotation des particules sur la structure de bande de différents cristaux phononiquesgranulaires est étudié. En effet, l’introduction de ces degrés de liberté additionnels rend possible l’existence de modes derotation qui interagissent fortement avec les modes transverses. Ce travail s’intéresse aussi à l’existence d’ondeslocalisées et d’ondes de surface dans des cristaux phononiques granulaires et en particulier à la comparaison des théoriesdéveloppées avec les prédictions de la théorie de Cosserat. Dans un premier temps, l’étude d’une chaîne phononique granulaire monoatomique est présentée. En considérant lachaîne semi-infinie avec une condition aux limites appliquée à son extrémité, le modèle analytique démontre l’existence demodes localisés, chaque mode étant composé de deux modes évanescents. Ensuite, une description théorique des modes se propageant dans un cristal phononique granulaire en deux dimensions est présentée. Les particules possèdent trois degrés de liberté, deux en translation et un en rotation. L’analyse des interactions entre ondes de translation et ondes de rotation permet de mettre en évidence une grande richesse de structure de bandes ainsi que des phénomènes particuliers (bandes interdites complètes, cône de Dirac, modes non-monotones, phénomène de double réfraction). Dans un dernier temps, une analyse de l’existence d’ondes de Rayleigh et de cisaillement horizontal dans un cristal phononique granulaire en trois dimensions est effectuée. Les limites de la théorie de Cosserat dans la description d’ondes acoustiques de surface dans les milieux micro- et nano-inhomogènes sont établies. / This work is devoted to the analysis of propagating and surface acoustic waves in granular phononic crystals in thelinear regime. First, the propagation and localization of transversal-rotational waves in a two-dimensional granularchain of equal masses are analyzed. By considering the semi-infinite chain with a boundary condition applied at itsbeginning, the analytical study demonstrates the existence of localized modes, each mode composed of two evanescentmodes. Secondly, the phononic properties of a two-dimensional discrete phononic crystal, made of circular cross-section, infinitely long contacting elastic cylinders arranged on a simple cubic lattice, are described analytically. The theoretical analysis provides a clear physical explanation for the existence of a zero-group velocity point of the lowest-energy acoustic mode in particular directions of the phononic crystal and demonstrates the birefraction phenomenon. Finally, the existence of surfaces elastic waves at mechanically free surface of granular phononic crystals is presented. Depending on the degrees of freedom of the particles, different types of surface waves exist in the structure. First, Rayleigh type surface waves aredemonstrated in a granular phononic crystal with particles possessing two translational and one rotational degrees offreedom; and secondly, shear-horizontal surface waves are studied in a granular phononic crystal with particlespossessing two rotational and one translational degrees of freedom. A comparison with surface waves predicted by theCosserat theories is made in order to establish the limitations of the Cosserat theories.
942

Les formes d’appropriation dans la musique savante chilienne, XXe-XXIe siècles : transfert culturel, acculturation, métissage / Forms of appropriation in the Chilean concert music, 20th-21st centuries : cultural transference, acculturation, hybridization

Gómez Gálvez, Mauricio 27 November 2017 (has links)
Cette thèse se focalise sur l’étude de quatre compositeurs chiliens contemporains de la seconde moitié du XXe siècle/début du XXIe (Cirilo Vila, Sergio Ortega, Patricio Wang et Andrés González), dont l’échelonnement générationnel permet d’embrasser un demi siècle de musique, et ayant pour dénominateur commun le fait d’avoir mené des carrières dans l’espace « euro-latinoaméricain ». La première partie de la thèse présente un panorama succinct de la musique savante chilienne dès l’indépendance du pays au XIXe siècle, en mettant l’accent sur le processus d’institutionnalisation de la vie musicale au pays, ainsi que sur les discours explicitement ou implicitement énoncés sur l’identité nationale/culturelle en musique. La deuxième partie analyse en détail, à travers une approche biographique, les parcours transnationaux et les œuvres des quatre compositeurs choisis, afin de comprendre, entre autres aspects, comment opèrent les processus de changement culturel à l’échelle d’une vie artistique. Enfin, la troisième partie présente une série d’études centrées sur l’analyse du rôle de passeurs culturels joué par les compositeurs chiliens (à la fois en tant que pédagogues et en tant que traducteurs de langages musicaux exogènes) ; l’impact de la circulation internationale et la globalisation ; les liens entre musique et politique, ainsi qu’entre art savant et populaire ; le rôle de la France et de l’Europe dans les processus d’acculturation ; les résultats du métissage culturel (à travers des cas concrets) ; ces études se complétant par une typologie des formes d’appropriation sonore opérés dans la musique de ces compositeurs. / This thesis focuses on the study of four contemporary Chilean composers from the second half of the 20th century and beginning of 21st century who developed their careers in the ‘euro-latin-american’ space (Cirilo Vila, Sergio Ortega, Patricio Wang, and Andrés González), and whose generational intersections allow to cover half a century of music. The first part of the thesis presents a brief panorama of Chilean concert music, from the independence of the country at the beginning of the 19th century until our days. The survey emphasizes the process of institutionalization of the musical life, as well as the implicit or explicit discurses, which are presented regarding the national cultural identity in relation to music. The second part analyzes in detail, through a biographical approach, the transnational trajectories of the four composers under study. The aim is to understand, among other aspects, how the processes of cultural change work at the level of a given artistic life. The third part, attempts to elucidate 1. the specificity of Chilean musicians through a multifactorial approach, presenting a series of studies towards analyzing the role of cultural transmitter performed by Chilean composers (within their double function as pedagogues and translators of exogenous languages); 2. the impact of the international circulation and the globalization on their works; 3. the links between music and politics as well as the links between high and popular art; 4. the role of France and Europe in the processes of acculturation; 5. the results of cultural hybridization (through concrete cases), and finally, 6. a typology of the ways of sonic appropriation.
943

Molecular Characterization of Early Dedifferentiation in Newt Forelimb Regeneration

Vanstone, Jason January 2013 (has links)
Newts have the incredible ability to regenerate many different organs and tissues as adults, including the limbs. Limb regeneration occurs via the dedifferentiation of stump tissue and the formation of a blastema, which provides the majority of cells for the regenerate. Despite all that we have learned about dedifferentiation and blastema formation, the cellular and molecular mechanisms underlying these processes are still poorly understood. We used representational difference analysis (RDA) to identify genes involved in the early dedifferentiation process in newt forelimb regeneration. Our analysis identified approximately 410 unique genes that were differentially regulated during this process. Microarray analysis was used to determine the expression profile of these genes throughout limb and tail regeneration. We used quantitative PCR (qPCR) to validate the expression of a subset of these genes [β-catenin, wntless, dapper, thymosin-β 4 (Tβ4), and thymosin-β 10/15 (Tβ10/15)] in regenerating limb and tail tissue, as well as in differentiating newt myoblasts. We also verified the expression of these genes in the regenerating newt limb using immunohistochemistry (IHC) and in situ hybridization (ISH). Finally, we performed a functional analysis on β-catenin, wntless, dapper, and Tβ4 by overexpressing these genes in mouse myoblasts to examine their effects on differentiation and potential roles in dedifferentiation. Quantitative PCR verified the expression of β-catenin, wntless, dapper, and Tβ4 during limb regeneration and IHC/ISH localized the β-catenin and Tβ4 proteins to the blastema during regeneration. Tβ10/15 was shown by qPCR to be expressed in the tail during regeneration. Overexpression of newt β-catenin, wntless, dapper, and Tβ4 in mouse myoblasts showed that each of these genes has an inhibitory effect on the differentiation of myoblasts into myotubes and, therefore, may play a role in promoting or maintaining the dedifferentiated state. Our work has identified a large number of genes with potential roles in regulating the dedifferentiation process during newt forelimb regeneration. We have also laid a framework from which much more work can be done by drawing on the genes we have identified and the microarray data, which indicate ideal follow-up candidates. Our analysis of specific genes has also increased our understanding of the molecular events occurring during the dedifferentiation process in the regenerating newt limb.
944

Expression and Functional Analysis of pthrp1 and ihha in the Regeneration of Bones in Zebrafish Caudal Fin

Al-Rewashdy, Ali January 2013 (has links)
The parathyroid hormone related protein (PTHrP) and Indian Hedgehog (IHH) are two secreted molecules, acting as paracrine factors during embryonic development and post-natal growth of endochondral bones. PTHrP and IHH are essential factors for the regulation of chondrocyte proliferation and differentiation. However, it has previously been shown that PTHrP and IHH are also expressed in the chick and mouse embryos intramembranous bones, which do not form through a cartilage intermediate and in which chondrocytes are absent. Similarly, the zebrafish orthologs, pthrp1 and ihha, are also expressed during the regeneration of the intramembranous bones of the fin rays of the zebrafish caudal fin. This surprising observation led us to further analyze the expression and function of pthrp1 and ihha in the regenerating fin rays. Gene expression analysis using in situ hybridization shows that pthrp1 is expressed in a stripe of cells located within the domain of expression of ihha in the newly differentiating osteoblasts in the regenerating fin rays. Also, pthrp1 expression is observed at the level of the joints between the bone segments forming the rays and co-localizes with the expression domain of evx1, a transcription factor that has been implicated in the formation of joints in the caudal fin. Furthermore, RT-PCR analyses show that pthrp2 and the pthrp receptors mRNA (pth1r, pth2r and pth3r) are also present in the fin regenerate. Finally, functional analysis shows that the knockdown of pthrp1 or ihha expression by electroporation of morpholinos induces a delay of the regenerative outgrowth of the fin. These results suggest that pthrp1 and ihha may be involved in the regulation of proliferation and differentiation of chondrocyte-like osteoblasts in the fin rays, playing a role similar to that described in the mammalian growth plate of endochondral bones. In addition, pthrp1 is possibly an important factor involved in the formation and maintenance of joints of the dermal bones of the fin rays.
945

Les usages sociaux et les logiques économiques de l'audiovisuel sur smartphone / Social uses and business logics of audiovisual media on smartphone

Sonet, Virginie 14 November 2014 (has links)
L’audiovisuel sur smartphone est un phénomène complexe et en construction. La mobilité et l’hybridation caractérisent ce nouveau territoire audiovisuel et cette thèse cherche à comprendre en quoi ces deux dimensions contribuent à la construction des usages sociaux et des logiques économiques de l’audiovisuel sur smartphone. À partir de plusieurs enquêtes qualitatives et d’une observation des offres des chaînes sur ce nouvel écran, ce travail analyse comment les utilisateurs et les acteurs de l’audiovisuel particulièrement les chaînes de télévision se saisissent de ce nouvel écran.Ce territoire audiovisuel est d’abord contextualisé, puis une lecture originale de l’évolution de l’audiovisuel est présentée, au prisme de disruptions d’ordre technologique, économique et d’usage. La construction de la posture scientifique reposant sur une approche interdisciplinaire est ensuite exposée. Dès lors, cette thèse met en évidence que la mobilité participe de l’appropriation du smartphone en tant qu’écran audiovisuel, notamment à travers les dimensions de contexte et de contraintes technologiques, commerciales, sociales. Quant au déploiement des modèles économiques des chaînes de télévision sur cet écran, il est contraint par un environnement technoéconomique imposé par les plateformes mobiles (comme Apple et Google). Avec la dimension d’hybridation, la thèse montre que les usages se construisent dans une logique d’entrelacement des pratiques audiovisuelles et des pratiques de communication et de connexion. Les chaînes de télévision réagissent en proposant des applications enrichies, en se déployant dans les réseaux socionumériques et en développant des dispositifs interactifs entre le smartphone et le téléviseur. Autant de nouvelles modalités d’agrégation susceptibles de drainer des implications économiques défavorables aux chaînes. / Watching and delivering video contents on smartphone is a complex phenomenon because it is forming as we investigate it. Both dimensions of mobility and hybridization characterize this new media territory and this thesis explains how their contribution leads to the construction of the social uses and the economic logics. Through several qualitative surveys based on interviews with users and professionals and a long term observation of the TV offers on this new screen, this research analyzes how the users on one hand and the broadcasting industry (TV networks) on the other hand, seize this new screen.This new audiovisual field is put into perspective by drawing up its offers overview and the first observed uses. An original reading of the audiovisual field evolution with the prism of technological, economical and use disruptions is then presented, and the construction of our scientific position is described, by explaining the interdisciplinary approach.Therefore, this research highlights that the mobility contributes to the appropriation of the smartphone as an audiovisual screen, essentially through the dimensions of context, as well as technological, commercial and social constraints. It also analyzes how the techno-economic environment, generated by the mobile platforms (Apple and Google), constrains the deployment of French TV networks’ business models on this new screen. With the dimension of hybridization, this thesis explains that the uses are expanding through the interlacing of communication, connection and audiovisual uses. Therefore, Television Networks try to conquer the attention of smartphone users by providing enhanced applications, by spreading in Social Networking Sites and by developing interactive systems between the smartphone and theTV set. But, these new aggregations often come with adverse economic implications.
946

Tests of Reproductive Isolation Between the Fishes Fundulus heteroclitus and F. grandis

Barbas, Ruthie E 01 January 2016 (has links)
The closely related killifishes Fundulus heteroclitus and F. grandis hybridize in a small region where their ranges overlap in coastal northeastern Florida. Hybrids of these species are rare in frequency within the contact zone, suggesting the presence of relatively strong reproductive isolation between these species. The objective of this study was to elucidate barriers to reproduction between F. heteroclitus and F. grandis in the lab, as well as to quantify the relative strengths and contributions of various isolating barriers. Pre-zygotic (mating and fertilization) and post-zygotic (hatching) barriers were investigated by performing a variety of choice and no-choice laboratory mating experiments. The results revealed that under no-choice conditions, barriers to mating had the biggest influence on hybrid production in F. grandis, whereas hatching barriers contributed to the majority of reproductive isolation in F. heteroclitus. However, under choice conditions pre-zygotic barriers had the greatest influence on both species’ ability to produce hybrids. The total relative reproductive isolation that was observed in females of each species was stronger in F. heteroclitus than in F. grandis overall, and was nearly complete in F. heteroclitus females under choice conditions while moderate in F. grandis females. These results reveal an asymmetry in the potential gene flow between these two species, with F. grandis being more likely to hybridize than F. heteroclitus in the absence of environmental influences.
947

Efeitos da infecção por Rickettsia rickettsii sobre o perfil de expressão gênica do carrapato vetor Amblyomma cajennense. / Effects of infection with Rickettsia rickettsii on the gene expression profile of the tick vector Amblyomma cajennense.

Larissa Almeida Martins 06 May 2014 (has links)
O agente etiológico da Febre Maculosa das Montanhas Rochosas (RMSF), conhecida no Brasil como Febre Maculosa Brasileira, é a bactéria Rickettsia rickettsii. Essa bactéria é transmitida ao homem pela picada de diferentes espécies de carrapatos ixodídeos. No Brasil, os vetores são Amblyomma cajennense e A. aureolatum. As taxas de prevalência de R. rickettsii nas populações de carrapatos de áreas endêmicas para RMSF são baixas, em geral abaixo de 1%. Essa baixa prevalência parece estar associada a menores taxas reprodutivas e de sobrevivência de linhagens infectadas, sugerindo que R. rickettsii seja patogênica também para os seus vetores. Infecções experimentais demonstraram que 80-100% dos indivíduos de uma colônia de A. aureolatum mantida em laboratório são infectados por R. rickettsii, enquanto apenas 10-60% de A. cajennense adquirem a bactéria. Esses dados indicam que as respostas dessas duas espécies de carrapatos à infecção sejam diferentes, resultando em diferentes taxas de prevalência da bactéria. Dessa maneira, a caracterização molecular das interações entre carrapatos do gênero Amblyomma e a bactéria R. rickettsii é importante, podendo gerar informações não somente para o esclarecimento acerca dos mecanismos de patogenicidade de R. rickettsii para os carrapatos, mas também para um melhor entendimento dos mecanismos responsáveis pela aparente restringência de A. cajennense à infecção. Assim, os objetivos do presente estudo foram: (i) analisar os efeitos da infecção por R. rickettsii sobre o perfil de expressão gênica de carrapatos A. cajennense por hibridação subtrativa por supressão (SSH), (ii) validar os dados de SSH por reação em cadeia de polimerase quantitativa precedida por transcrição reversa (RT-qPCR) e (iii) caracterizar funcionalmente dois genes com expressão induzida pela infecção por RNA de interferência (RNAi). Após a análise bioinformática dos dados de SSH, 44 sequências únicas foram obtidas, das quais 36 representam genes com expressão induzida e 8 genes com expressão reprimida pela infecção. A indução dos genes codificadores da subunidade I da citocromo c oxidase (COX1), da subunidade IV da NADH desidrogenase, de uma proteína com domínio de inibidor de serina-proteases Kunitz-type (papilina-like), identificados por SSH, e de um peptídeo antimicrobiano (hebraeína), foi confirmada por RT-qPCR. O silenciamento gênico da hebraeína e da papilina-like não teve nenhum efeito na aquisição de R. rickettsii pelo vetor, indicando que, isoladamente, não são responsáveis pela proteção de A. cajennense contra a infecção. Os dados gerados pelo presente estudo abrem perspectivas para que outros genes sejam avaliados quanto ao seu papel na aquisição de R. rickettsii, os quais, no futuro, podem ser considerados como alvos para o desenvolvimento de vacinas. / The etiologic agent of the Rocky Mountain Spotted Fever (RMSF), also known as Brazilian Spotted Fever in Brazil, is the bacterium Rickettsia rickettsii. This rickettsia is transmitted to humans by the bite of various tick species. In Brazil, Amblyomma cajennense and A. aureolatum are known as vectors. The prevalence rates of R. rickettsii infected ticks in RMSF endemic areas are low, oscillating around 1%. These low prevalence rates seems to be associated with lower reproductive and survival rates of infected ticks, suggesting that R. rickettsii is also pathogenic to its vectors. Experimental infections with R. rickettsii have demonstrated that 80 to 100% of A. aureolatum ticks from a laboratory colony acquire this bacterium, whereas only 10 to 60% of A. cajennense ticks become infected. These results indicate that the responses of these two tick species against infection are different, resulting in different prevalence rates of the bacterium. Therefore, the elucidation of the interactions between ticks of the genera Amblyomma and the bacterium R. rickettsii at a molecular level is important to provide information to better understand the mechanisms of pathogenicity of R. rickettsii against ticks as well as for the elucidation of the mechanisms responsible for the apparent refractoriness of A. cajennense against infection. Therefore, the objectives of the current study were: (i) analyze the effets of the infection with R. rickettsii on the gene expression of ticks A. cajennense by suppression subtractive hybridization (SSH), (ii) validate SSH data by reverse transcription quantitative polymerase chain reaction (RT-qPCR), and (iii) functionally characterize two genes induced by infection using RNA interference (RNAi). After bioinformatics analysis of SSH data, 44 unique sequences were obtained, among which 36 represent genes with expression induced and 8 repressed genes by infection. The induction of genes encoding subunit I of cytochrome c oxidase (COX1), the NADH dehydrogenase subunit IV, a protein containing Kunitz-type inhibitor domain (papilin-like), identified by SSH, and an antimicrobial peptide (hebraein), was confirmed by RT-qPCR. The effects of knockdown of hebraein and papilin-like encoding genes had no effect on the acquisition of R. rickettsii by the vector. Data of the current study may be used to evaluate the role of other genes in acquisition of R. rickettsii, which, in the future, may be considered as target for vaccine development.
948

Expressão temporal dos genes do nucleopoliedrovírus Anticarsia gemmatalis e sua influência sobre a célula. / Temporal expression of the Anticarsia gemmatalis nucleopolyhedrovirus genes and its influence on the cell.

Juliana Velasco de Castro Oliveira 06 October 2010 (has links)
Desde a década de 80, o nucleopoliedrovírus Anticarsia gemmatalis (AgMNPV) tem sido utilizado no Brasil como agente de controle biológico no combate à lagarta-da-soja, resultando para o país significativos benefícios econômicos e ecológicos. Este vírus envelopado, pertencente à família Baculoviridae, possui DNA circular de fita dupla (132.239 pb) contido em um capsídeo protéico, que pode estar ocluído em uma matriz para-cristalina. Neste trabalho, analisamos a expressão temporal de seus genes em duas linhagens celulares (UFL-AG-286 e IPLB-SF-9), por PCR em tempo real. Outro objetivo foi o estudo do efeito da multiplicação viral na malha gênica celular (GRN), visando analisar a expressão gênica celular diferenciada durante a infecção, através da técnica de hibridização subtrativa. Verificamos que todas as ORFs (exceto ORFs 64 e 83, que provavelmente não codificam a genes) foram expressas, com diferenças significativas entre as linhagens, principalmente em relação ao nível de expressão. Apesar disso, o grupo de genes ligados a replicação apresentou perfil de expressão similar nas duas linhagens, possivelmente por este ser um processo essencial à replicação viral. De uma forma geral, todos os genes apresentaram um perfil de expressão mais precoce do que o relatado na literatura, o que poderia ser tanto devido à replicação precoce do DNA do AgMNPV quanto até mesmo consequência da sensitividade do método utilizado. O agrupamento dos genes por k-means seguiu, em sua maioria, a hora pós-infecção (p.i.) onde a expressão de cada gene foi detectada, o que é coerente com a expressão gênica em cascata de baculovírus. Entretanto, por esta classificação não foi possível predizer função gênica para os genes pouco caracterizados. Em relação ao efeito da infecção do AgMNPV na GRN da UFL-AG-286, observamos que em 20h p.i., uma grande diversidade de genes e funções celulares foram hipo-expressas. / Since the 80s, the Anticarsia gemmatalis nucleopolyhedroviruses (AgMNPV) has been used in Brazil as a biological control agent against the Anticarsia gemmatalis caterpillar in soybean fields, resulting in considerable economic and ecological benefits. This enveloped virus belongs to the Baculoviridae family. It has circular double-stranded DNA (132239 bp) enclosed in a capsid, which can be occluded in a crystalline matrix. In this work we elucidated the temporal gene expression profile of the AgMNPV-2D in two cell lines (UFL-AG-286 and IPLB-SF-9), using a real time PCR. Another objective was to study the effect of viral replication on the cellular gene regulatory network (GRN), in order to analyze the differential cellular gene expression during infection, using subtractive hybridization method. We found that most ORFs (except 64 and 83 ORFs that probably do not encode genes) were expressed, with significant differences between cell lines, mainly in expression intensity. However, the group of genes associated with viral DNA replication had similar expression profile in both lineages, possibly because replication is an essential process for viral multiplication. In general, most genes had earlier expression than reported in the literature, probably due to the early DNA replication in AgMNPV. Moreover, this could be a consequence of the method sensitivity used herein. We clustered genes with the k-means algorithm according to the time pos infection (p.i.) in which each gene expression was first detected and found it to be consistent with the typical cascade of gene expression known for baculovirus. Nonetheless, following this classification, it was not possible to predict gene function for poorly characterized genes. When looking at the impact of viral replication on the host GRN using subtractive hybridization, we found considerable inhibition of cellular transcription at 20h p.i. Furthermore at this time, a large and diverse set of cellular genes and functions were found to be hypo-regulated, indicative of an extensive effect of AgMNPV infection on the UFL-AG-286 GRN.
949

Caracterização molecular de proteínas secretadas da família VAL (Venon Allergen-Like Protein) de Schistosoma mansoni e avaliação como antígenos vacinais. / Molecular characterization of secreted proteins of Schistosoma mansoni VAL (Venom Allergen-Like Protein) family and evaluation as vaccine candidates.

Rafaela Sachetto Fernandes 02 March 2016 (has links)
A esquistossomose é uma doença causada por trematódeos do gênero Schistosoma. Dentre os genes identificados no transcriptoma do parasita, membros da família gênica SmVAL (Schistosoma mansoni Venom Allergen-Like) foram apontados como candidatos vacinais. SmVALs foram identificadas em secreções de cercárias e esquistossômulos cultivados in vitro, os transcritos SmVAL4 e 24 foram localizados nas glândulas acetabulares de germ ball e a proteína nativa SmVAL4 foi identificada em extrato de cercárias, indicando funções durante a penetração da pele. Já os transcritos SmVAL13 e 14 foram localizados na glândula esofágica anterior de vermes adultos, sugerindo papéis no processo de alimentação sanguínea. A imunização com as proteínas rSmVAL4, 6, 7, 13, 14 e 18 coadministradas não protegeu camundongos contra o desafio experimental, porém, observou-se uma diminuição do número de fêmeas e do número de ovos no grupo imunizado. A investigação de funções para as proteínas secretadas mostrou que a rSmVAL18 interage com plasminogênio in vitro favorecendo a invasão do hospedeiro. / Schistosomiasis is a disease caused by trematodes of the genus Schistosoma. Among the genes identified in the parasite transcriptome, members of SmVAL (Schistosoma mansoni Venom Allergen-Like) gene family were proposed as vaccine candidates. SmVALs were identified in cercariae and schistosomule secretions in vitro, the SmVAL4 and 24 transcripts were located to the germ ball acetabular glands and SmVAL4 native protein was identified in cercariae extract, indicating functions in skin penetration. On the other hand, SmVAL13 and 14 transcripts were located to the anterior esophageal gland of adult worms, suggesting roles in the blood feeding processes. Immunization with rSmVAL4, 6, 7, 13, 14 and 18 proteins co-administered did not protected mice against experimental challenge, however, there was a decrease in the number of females and the number of eggs in the immunized group. The investigation of functions for secreted proteins showed that rSmVAL18 interacts with plasminogen in vitro thus favoring the host invasion.
950

Evolução em Cycloramphidae : diversidade e especiação na Mata Atlântica brasileira /

Sá, Fábio Perin de. January 2019 (has links)
Orientador: Célio Fernando Baptista Haddad / Resumo: As forças de seleção natural e sexual atuam sobre os indivíduos e podem os levar ao isolamento reprodutivo. O acúmulo de modificações evolutivas pode levar ao surgimento de novas entidades. Espécie é unidade basal em biologia; assim, com sua exuberante biodiversidade, a Mata Atlântica é uma floresta neotropical fundamental para estudos de processos evolutivos em anfíbios anuros. Reunindo os gêneros Cycloramphus, Thoropa e Zachaenus, a família Cycloramphidae agrupa espécies de anuros saxícolas e terrestres, todas endêmicas da Mata Atlântica brasileira. Pelos seus hábitos especializados de vida e reprodução, os cicloramfídeos formam um grupo atrativo para estudos evolutivos. Na presente tese são apresentados quatro capítulos que abordam três escalas distintas da evolução: a diversificação entre espécies, populações e indivíduos. São abordados: (1) a filogenia molecular multilocus de Cycloramphus-Zachaenus, demonstrando que a evolução da terrestrialidade no clado se correlaciona com o dimorfismo sexual em tamanho; (2) a diversificação fenotípica associada a diversificações genéticas em populações de C. boraceiensis e C. dubius, demonstrando que estas duas espécies-irmãs saxícolas apresentam zona de contato e hibridação; (3) o sistema de acasalamento promíscuo e as relações sociais em C. boraceiensis, demonstrando que tamanho das fêmeas e dos machos e parentesco genético influenciam a formação dos casais; e (4) o sistema de acasalamento poligínico com fidelidade na espécie saxíco... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Natural and sexual selection forces act on individuals and may lead to reproductive isolation. The increase in evolutionary modifications may lead to the emergence of new entities. Species is the basal unity in biology; thus, with its exuberant biodiversity, the Atlantic rainforest is a fundamental Neotropical forest for studies of evolutionary processes in anuran amphibians. Comprising the genera Cycloramphus, Thoropa, and Zachaenus, the family Cycloramphidae gathers saxicolous and terrestrial anuran species, all endemic to the Brazilian Atlantic rainforest. Because of their specialized life and reproductive habits, cycloramphids are an attractive group for evolutionary studies. In the present thesis we show four chapters that address three distinct scales of evolution: the diversification among species, populations, and individuals. We goaled: (1) the multilocus molecular phylogeny of Cycloramphus-Zachaenus, demonstrating that the evolution of terrestriality in the clade is correlated with the sexual size dimorphism; (2) the phenotypic diversification associated with the genetic diversifications in populations of C. boraceiensis and C. dubius, demonstrating that these two saxicolous sister species show a contact zone and hybridization; (3) the promiscuous mating system and the social relations in C. boraceiensis, demonstrating that female and male sizes, and mate relatedness influence pair formation; and (4) the polygynic mating system with fidelity in the saxicolous specie... (Complete abstract click electronic access below) / Doutor

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