O presente trabalho estudou a expressão da conexina 43 nas células trofoblásticas gigantes bovinas, em especial nas células trofoblásticas gigantes binucleadas. Foram utilizadas 12 amostras de placenta bovina, divididas em três grupos segundo a fase gestacional, primeiro terço, segundo terço e terceiro terço da gestação. O tecido placentário foi fixado em solução metacarn e, posteriormente, submetido ao método tradicional de inclusão em parafina. A detecção da conexina 43 foi realizada através de imuno-histoquímica, pelo método de amplificação da tyramida, utilizando como anticorpo primário policlonal a imunoglobulina de coelho anti-conexina 43 de camundongo. Os resultados deste trabalho indicaram que as células trofoblásticas gigantes bovinas são capazes de expressar a conexina 43 nas três fases da gestação. A distribuição da conexina 43 evoluiu com a progressão da gestação, mas ficou limitada ao interior das células trofoblásticas gigantes bovinas, sem formar marcações pontuais na membrana citoplasmática que pudessem indicar a formação de junções comunicantes. A avaliação de diferentes protocolos histológicos e imuno-histoquímicos permitiu estabelecer a melhor metodologia para a preservação do arranjo tecidual da placenta bovina e a identificação da conexina 43 nas células trofoblásticas gigantes bovinas / The present study has researched the expression of Connexin-43 in bovine trophoblast giant cells, especially in binucleate trophoblast giant cells. Twelve samples of bovine placenta were used, divided into three groups according to the gestational phase, first part, second part and third part of gestation. The placental tissue was fixed in Methacarn solution and later submitted to the traditional method, that is, embedded in paraffin. The detection of Connexin-43 was done through immunohistochemistry by the tyramide amplification method, using as polyclonal primary antibody, rabbit immunoglobuline anti-mouse Connexin-43. The results of this study have revealed that the bovine trophoblast giant cells are capable of the expression of Connexin-43 in the three phases of gestation. The distribution of Connexin-43 evolved as gestation progressed, but was limited to the interior of the bovine trophoblast giant cells without punctate markings in the cytoplasmic membrane which could indicate the formation of communicating junctions. The assessment of different histological and immunohistochemical protocols allowed us to establish the best methodology for the preservation of the tissue arrangement of bovine placenta and the identification of Connexin-43 in the bovine trophoblast giant cells

O objetivo do presente estudo é descrever as características físicas, químicas, morfológicas e funcionais do sêmen do tamanduá-bandeira (Myrmecophaga tridactyla) em cativeiro. Estes resultados representam um dos primeiros requisitos para o conhecimento das características seminais da espécie, visando, em médio prazo, a aplicação de técnicas de reprodução assistida e a formação de bancos de germoplasma. Treze animais foram submetidos à colheita de sêmen em zoológicos no estado de São Paulo Brasil. O método para colheita de sêmen foi a eletroejaculação, semelhante ao realizado em várias espécies silvestres e domésticas, resultando em onze amostras colhidas de nove indivíduos (69,23%). Os testes convencionais indicaram um volume médio de 1,30 ± 0,58 ml, a motilidade média de 33,18 ± 20,14%, o vigor médio de 2,30 ± 0,65, a concentração média de 129,41 ±114,3 x 106 / cm3, o pH médio de 7,44 ± 0,60. A avaliação morfológica apresentou média de defeitos totais de 64,53 ± 19,97%, defeitos maiores 53,77 ± 33,22% e defeitos menores 10,75 ± 6,23%. Nos testes funcionais, a avaliação da integridade da membrana acrossomal mostrou uma média de 16,3 ± 9,3% de danificadas. A avaliação da integridade da membrana plasmática mostrou uma média de 18,9 ± 12,2% de danificadas. A avaliação da atividade mitocondrial revelou as seguintes médias: Classe I = 66,4 ± 19,0%; Classe II = 18,7 ± 9,1%; Classe III = 8,0 ± 6,3%; Classe IV = 3,9 ± 3,1% e Classe V = 3,0 ± 2,9%. A avaliação da fragmentação de cromatina resultou em uma média de 13,21 ± 9,13%. Conclusão: foi demonstrada a aplicabilidade da eletroejaculação na colheita de sêmen de tamanduás-bandeira. Os testes possibilitaram uma análise detalhada das características seminais da espécie, aspectos estes ainda inéditos na literatura mundial. Houve grande variação nos resultados obtidos, refletindo diferenças das condições de manejo e de idade entre os indivíduos e, possivelmente um baixo número amostral estudado. Novos estudos devem ser realizados em animais de vida livre. / The purpose of the present study was to describe the physical, chemical, morphological, and functional features of semen collected from Giant Anteaters (Myrmecophaga tridactyla) raised in captivitya first step toward the feasibility of assisted reproduction techniques and germplasm banks for this species in the mid-term future. Electroejaculation, a method currently applied to a number of wild and domestic species, was performed in 13 animals housed in zoos located in the state of São Paulo, Brazil, yielding 11 samples from 9 animals (69.23%). The following mean values were obtained: volume, 1.30 ± 0.58 mL; motility, 33.18 ± 20.14%; vigor, 2.30 ± 0.65; concentration, 129.41 ± 114.3 x 106 cm-3; pH, 7.44 ± 0.60. Major and minor defects accounted for 53.77 ± 33.22% and 10.75 ± 6.23% of the total, respectively (mean total defect rate, 64.53 ± 19.97%). Damage was found in 16.3 ± 9.3% of acrosomal membranes and 18.9 ± 12.2% of plasma membranes. Mitochondrial activity, categorized as Classes I through V, was 66.4 ± 19.0%, 18.7 ± 9.1%, 8.0 ± 6.3%, 3.9 ± 3.1%, and 3.0 ± 2.9%, respectively. Chromatin fragmentation rate was 13.21 ± 9.13%. Conclusion: The study demonstrated the feasibility of applying electroejaculation to Giant Anteaters for semen collection, allowing for a detailed description of semen features previously unreported for this species. The large variation found in the results reflects differences in management conditions, age range, and possibly the small number of sampled animals, thus warranting further studies with free-ranging specimens.

Nosso objetivo e estudar os principais mecanismos de foto absorção no ANTPOT.232 TH entre 7 e 60 Mev, ressonâncias gigantes e mecanismo do quase-deuteron, associados ao decaimento por fissão. Para isso, fizemos medidas da seção de choque de eletrofissão no ANTPOT.232 TH, entre as energias de 7 a 60 Mev, no laboratório do acelerador linear do IFUSP. Utilizamos, na analise, o formalismo dos fótons virtuais, que relaciona a seção de choque de fotofissão a seção de choque de eletrofissão. Foi utilizada a seção de choque de fotofissão medida em livermore e calculamos a seção de choque de fotoabsorção e2 (t=0 e t=1), além da seção de choque de fotoabsorção obtida via quase-deuteron. Verificamos que a contribuição predominante para a seção de choque de eletrofissão e a da componente de dipolo elétrico, sendo as demais contribuições (quadrupolo elétrico e modelo modificado do quase-deuteron) uma ordem de grandeza inferior a esta. / Our objective is to study the main photoabsorption mechanisms in 232T]n between 7 and 60 Mev, namely, Giant Resonances and Quasi-Deuteron, associated to fission decay. We performed electrofission measurements at the linear accelerator of IFUSP. In the analysis, the Virtual Photon Formalism, that relates the photofission cross section to the electrofission cross section, was used. In the calculations, the photofission cross section measured at Livermore Laboratory was used. The E2 photoabsorption and quasi-deuteron photoabsorption cross sections were calculated. We concluded that the most important contribution to the electrofission cross section comes from the El- giant resonance component, the other ones (E2 giant resonance component and quasi-deuteron mechanisms) being 1 or 2% of total electrofission cross section.

Orientadores: Marcelo Knobel, Kleber Roberto Pirota / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-19T10:38:36Z (GMT). No. of bitstreams: 1 ValenzuelaAcuna_LeninaAlejandra_D.pdf: 6580739 bytes, checksum: f221d85ff3a59859f824164188637f28 (MD5) Previous issue date: 2011 / Resumo: No nosso trabalho utilizamos o fenômeno da magnetoimpedância gigante (GMI) como uma ferramenta de pesquisa na caracterização de ferromagnetos amorfos. Estes materiais são muito moles do ponto de vista magnético, o que pode servir para diversas aplicações, tais como na construção de sensores e de dispositivos de alta frequencia. Na primeira parte da tese veremos como a GMI se torna uma técnica complementar na caracterização da cristalização em materiais amorfos. Na segunda parte da tese estudamos uma fita que apresenta histerese na GMI, de modo inédito utiliza-se o método de First Order Reversal Curves (FORC), em medidas da impedância. Os resultados apresentam um comportamento complexo, para os quais estamos propondo uma interpretação particular. Os materiais que mostram este comportamento podem ser úteis nas aplicações de, por exemplo, armazenamento de informação. Inicialmente, realizamos tratamento térmico convencional e por aquecimento Joule em fitas amorfas de composição Fe86Zr7Cu1B6 fabricadas pelo método melt spinning. Quando tratadas termicamente ocorre a cristalização de partículas a-Fe, e no geral o tamanho das partículas aumenta com o aumento da magnitude do tratamento (temperatura ou corrente). Nas medidas de magnetização vemos geralmente que a coercividade apresenta baixos valores e há um endurecimento nas amostras onde se observou um aumento no tamanho dos grãos no início da cristalização. Por outro lado, a fração cristalina nas amostras tem uma tendência ao aumento com o tratamento térmico, que se reflete nas medidas de raios X e da magnetização de saturação Ms. Vimos também que as medidas de GMI em função da frequência, apresentam resultados atípicos: diferente da relação com a raiz quadrada da frequência, a GMI máxima apresenta curvas que indicam uma diminuição da resposta GMI para frequências altas. Isto foi interpretado como sendo devido à não-homogeneidade da formação dos cristais no volume das amostras. Consideramos a relação inversa do coeficiente de penetração dm com a frequência. Vemos que com o aumento da frequência diminui a região onde circula a corrente ac a qual está mais próxima à superfície, onde há partículas maiores o que deixa o material magneticamente mais duro. Na segunda parte do trabalho apresentamos uma aplicação inovadora da união da técnica de caracterização FORC com medidas de GMI. Utilizamos fitas amorfas, de composição (FexCo1-x)70Si12B18 (x = 0,045; 0,048; 0,049; 0,050) que foram fabricadas pelo método melt spinning. Nestas induziu-se anisotropia transversal por meio de tratamentos térmicos junto à aplicação de tensão. A resposta GMI apresentou um comportamento histerético, o eu nos levou a querer usar a técnica FORC para entender a causa deste. A forma de interpretação das curvas e diagramas FORC apresentou um novo desafio. Sabemos que a variação da impedância é ocasionada pela variação da permeabilidade transversal na amostra. Foi proposta a hipótese de que o processo histerético se deve a uma transformação no tipo de paredes de domínio com o campo, de modo que cada tipo de parede tem uma µt associada. Observou-se também a dependência da distribuição FORC com a frequência, anisotropia, e relativa à componente da impedância (parte real ou imaginária) / Abstract: In this work, we used the giant magnetoimpedance (GMI) effect as a research tool to characterize ferromagnetic amorphous materials. These materials have ultra-soft magnetic features, which can be useful for various applications, e.g. sensors and high frequency devices. In the first part, we will see how GMI becomes a complementary technique to characterize the crystallization in amorphous materials. In the second place, we studied a ribbon that shows hysteresis in the GMI response. The First Order Reversal Curves (FORC) method was applied in impedance measurements as a novel technique. We are proposing a particular interpretation for the complex obtained results. The applications of these materials with hysteretic behavior can be useful to magnetic recording, for example. In the first part of the work, we induced the crystallizations of a-Fe particles in amorphous ribbons of composition Fe86Zr7Cu1B6 manufactured by melt spinning method, by thermal treatment (conventional and Joule heating). In general, the size of particles increases with the temperature or current of treatment. In magnetization measurements the coercivity has usually low values. There is a hardening in samples with bigger size grains, at the beginning of crystallization. On the other hand, the crystalline fraction in the samples has a tendency to increase with thermal treatment, which is reflected in measurements of X-rays and the saturation magnetization Ms. We have also seen that the GMI measurements as a function of frequency show rather atypical results: the maximum GMI as a function of frequency shows a decrease in the GMI response to high frequencies, that differ from the relationship with the square root of frequency. This was interpreted as being due to non-homogeneity of the formation of crystals in the volume of samples. If we consider the inverse relationship of penetration coefficient with frequency dm, we can see that with the increase of frequency decreases the region where the ac current flows, which, in turn, is closer to the surface. In this region there are larger particles, making the material magnetically harder. In the second part of the work, we present an innovative application of the junction of characterization technique FORC with measurements of GMI. We use amorphous ribbons of composition (FexCo1-x)70Si12B18 (x = 0,045; 0,048; 0,049; 0,050)produced by melt spinning. A transverse anisotropy was induced by thermal treatments with the application of stress. We applied the FORC technique in order to help to understand the hysteretic behavior in the GMI response. The interpretation of the GMI curves and FORC diagrams is a new challenge. We know that the variation of impedance is caused by the change of transverse permeability sample µ t. We proposed the hypothesis that the hysteretic process is due to a change in the type of domain walls with the field, so that each type of wall has an associated µt. We also observed the dependence of the FORC distribution with frequency, anisotropy, and with the components of the impedance (real or imaginary part) / Doutorado / Doutora em Ciências

Les conditions thermodynamiques régnant au sein des planètes géantes telles que Jupiter, Saturne et bon nombre des exoplanètes découvertes quotidiennement, impliquent que les interactions entre particules – atomes, ions, électrons – sont prépondérantes dans les enveloppes planétaires, principalement composées d'hydrogène et d'hélium, et déterminent les propriétés mécaniques et thermiques de ces objets. La caractérisation de ces plasmas denses est donc cruciale pour comprendre la structure et l'évolution de ces planètes géantes. Les simulations ab initio, utilisant la théorie de la fonctionnelle de la densité, ont montré leurs performances pour la caractérisation des espèces pures dans leur phase plasma dense, en reproduisant correctement les résultats des expériences de chocs par laser haute-puissance. Néanmoins, des écarts importants perdurent entre modèles planétaires et observations. Ils sont attribués à la non-idéalité du mélange H-He et de possibles transitions de phase. Dans ce travail de thèse, ces méthodes numériques ab initio ont été appliquées au cas des mélanges H-He. L'étude thermodynamique a révélé des déviations sensibles par rapport aux prédictions obtenues pour des mélanges idéaux. Par ailleurs, les calculs des propriétés de transport (conductivité électrique, thermique, propriétés optiques...) ont montré une transition isolant-conducteur du mélange, notamment par l'ionisation de l'hydrogène. Celle-ci s'accompagne, dans un certain domaine de paramètres, d'une séparation de phase entre l'hydrogène conducteur et l'hélium neutre. Ces calculs ont également permis d'établir des diagnostics pour les expériences laser, afin de pouvoir corroborer cet ensemble de résultats et obtenir, à terme, une équation d'état fiable du mélange H-He, applicable aux planètes géantes. / The thermodynamical conditions inside the giant planets - like Jupiter, Saturn or many of the daily discovered exoplanets – are such that the interactions between particles – atoms, ions, electrons – are highly dominant in the physics of giant planets envelope s, mostly made of hydrogen and helium in a plasma phase. The heat and mechanical properties of these planets are mainly determined by these interactions. Thus, it is of crucial interest to study these dense plasmas to understand the structure and the evolution of the giant planets. The dense plasma phase of the pure compounds has been successfully characterized by ab initio simulations using density functional theory. For instance, they correctly reproduced the results obtained in high-power laser chock experiments. Nevertheless, large discrepancies remain between planetary models and observations. A proposed hypothesis is a strong influence of the H-He mixture non-ideality and possible phase separations. In this work, these ab initio numerical methods have been applied to the H-He mixtures. The thermodynamical study has shown sensitive deviations from ideal mixtures. The estimates of the transport properties (electrical and heat conductivities, optical properties...) indicate an insulator-conductor transition in the mixture, associated with hydrogen ionization. In some conditions, demixing of conducting hydrogen and neutral helium has also been observed. These computations have allowed us to determine pathways to verify our results through laser experiments. This is the first step in the establishment of a reliable equation of state of H-He mixtures, usable in giant planets modeling.

Cellular membranes are important targets for many membrane-active peptides and drug compounds. Here we are interested in deciphering how lipid membranes are perturbed by several membrane-active molecules, including the transmembrane domain of the influenza M2 protein (M2TM), aggregates formed by a synthetic polyglutamine peptide, and three polyphenol compounds (i.e., tamoxifen, genistein, and verapamil). We employ phase-separated ternary lipid model membranes in the form of giant unilamellar vesicles (GUVs) to simulate raft-like structures that have been proposed to govern many important processes in plasma membranes (e.g., intracellular singling and trafficking). Specifically, we use fluorescent microscopy to interrogate how those membrane additives modulate the phase behavior of free-standing GUVs, as well as the miscibility transition temperature (Tm). We find that M2TM increases Tm and causes vesicle budding; polyglutamine aggregates disrupt lipid membranes; and the three polyphenol compounds exert disparate effects on GUV Tm.

L’étude des séismes géants de subduction présente un intérêt de premier ordre, car ils sontsuffisamment puissants pour exciter le manteau et déclencher sa relaxation visco-élastique. Cephénomène est caractérisé par des déformations à grande échelle spatiale (plusieurs milliers dekilomètres) et temporelle (plusieurs décennies). L’étude des déformations post-sismiques en surfacepar géodésie spatiale permet de contraindre les caractéristiques géométriques et rhéologiques del’interface de subduction, ouvrant ainsi la voie à l’étude du cycle sismique dans sa globalité.Le 27 février 2010 se produit le séisme de Mw 8.8, dans la région du Maule, au large du Chili. Lasubduction de la plaque Nazca sous la plaque continentale Sud-Américaine offre, pour la premièrefois, la possibilité de mesurer de manière continue et dense les déformations post-sismiques sur plusde 1500 km. Par ailleurs, plus de 10 ans de campagnes de mesures GPS, ont permis d’imager uncouplage très hétérogène tout au long de l’interface de subduction. L’imbrication alors visible entreles déformations post-sismiques et inter-sismiques, appuyée par l’étude de la sismicité historique,met ainsi en évidence les interactions inter-segments que seuls les modèles visco-élastiques de cyclesismique permettront de mieux comprendre.Cette thèse a été centrée autour de deux axes principaux, qui conduisent vers l’objectif finaldes modèles visco-élastiques de cycle sismique. Le premier et principal objectif est l’étude desdéformations post-sismiques du Maule. J’ai ainsi traité et analysé les cinq ans de données aprèsle séisme afin d’extraire le champ de déformation post-sismique. Ces données ont alors permis decontraindre les modèles visco-élastiques, grâce à la méthode des éléments finis. Un modèle combinéd’afterslip et de relaxation visco-élastique dans l’asthénosphère et dans un chenal à faible viscositétrès profond, permet ainsi d’expliquer le champ de déformation horizontal mais aussi verticalobservé. L’amplitude et la complexité des déformations en champ proche résulte de "l’afterslip",tandis que la relaxation dans le chenal permet de reproduire le très fort soulèvement de la Cordillèredes Andes. Enfin, la relaxation dans l’asthénosphère est responsable de l’extension sur plusieursmilliers de kilomètres des déformations post-sismiques. De plus, la continuité de l’effort de terrainet le traitement des données recueillies a permis de combler l’ultime gap de données. Il a ainsiété possible de déterminer un champ de vitesse inter-sismique continu sur la quasi totalité del’interface. Finalement, même si un modèle de cycle sismique à l’échelle de la subduction Chiliennen’a pas encore pu être réalisé, le modèle de post-sismique apporte déjà de nouveaux indices sur lesinteractions entre les différents segments de l’interface Chilienne, suite au dernier séisme. / The study of giant earthquakes on subduction zone represents a main interest. They are indeedsufficiently powerful to excite the mantle and trigger its viscoelastic relaxation, over a very largespatial (thousands of kilometers) and temporal (several decades) scale. Postseismic deformation,monitored by spatial geodesy, are a proxy to the geometrical and rheological characteristics of thesubduction interface, that will allow us to study the whole seismic cycle.On February 27th 2010 in the region of Maule, Chile, occurs the Mw 8.8 megathrust earthquake.Yet, the subduction of the Nazca plate beneath the continental South-American plate offers, forthe first time, the opportunity to measure continuously and densely the postseismic deformationfollowing the earthquake, over more than 1500 km. Otherwise, more than a decade of GPS repeatedmeasurements allowed to image a very heterogeneous coupling all along the Chilean interface. Thevisible imbrication between postseismic deformation and interseismic loading, supported by historicaland instrumental seismicity, highlights interactions between the segments. Viscoelastic modelsof seismic cycle appears to be the only way to understand these interactions.This PhD focused on two main axes, that will lead to the development of viscoelastic modelsof seismic cycle. The first part was dedicated to the study of postseismic deformation followingthe Maule earthquake. Therefore, we processed and analyzed very precisely GPS data in orderto extract the postseismic pattern and modeled it using the finite elements method. A combinedmodel of afterslip and viscoelastic relaxation in the asthenosphere and in a low viscosity channel,extending deep along the slab, can reproduce the complex deformation pattern, horizontaly and inverticaly. The amplitude and complexity of the near-field deformation result from aseismic slip onthe fault plane, while the great uplift of the Cordillera is reproduced by relaxation in the channel.The far field extension, up to 1600 km, entirely results from relaxation in the asthenosphere. Onthe other hand, the continuity of campaign measurements was the occasion to fill the ultimate gapof data, and thus estimate a continuous interseismic velocity field from the North of the Maulerupture zone up to North Chile. Finally, even if the final viscoelastic models of seismic cycle couldnot be processed yet, the present postseismic model already brings new insights on interactionsbetween the different segments of the Chilean interface, following the last Chilean earthquake.

The tropical forests of South and Southeast Asia hold the highest gliding squirrel diversity but our knowledge of species diversity, ecology and major threats is limited. The present study was undertaken in Arunachal Pradesh, Northeast India between June 2011 and March 2015 to address the paucity of data available on gliding squirrels. Based on field and literature surveys, 14 species of gliding squirrels were detected in the state of Arunachal Pradesh. However, species such as Biswamoyopterus biswasi, which is reported as endemic to Namdapha National Park, were not detected. The high gliding squirrel diversity in this region could be related to a diversity of forest types and its location between the Himalayas and the Indomalayan region. Encounter rates with four different species revealed that Petaurista petaurista was most frequently detected in Namdapha National Park. Major threats include hunting for traditional medicine, cultural purposes or bushmeat, and habitat loss due to forest degradation caused by shifting cultivation. In addition, more intensive studies on population, ecology and conservation status are needed in order to design species and site specific conservation action plans in this region which represents the highest diversity of gliding squirrels globally.

Master of Science / Department of Agronomy / Johanna A. Dille / Corn yield potential is limited by water deficit stress and limited soil nitrogen. Field and greenhouse experiments were conducted near Manhattan, KS in 2005 and 2006. The field experiment evaluated the influence of nitrogen (N) rate and increasing Palmer amaranth (PA) density grown alone and in competition with corn in two moisture environments. In 2006 the dryland environment was very drought stressed, while 2005 had more intermediate conditions. Weed-free corn yields were approximately half in dryland environments compared to the irrigated environment across years. Increasing PA density increased corn yield loss similarly in both 2005 environments and in 2006 dryland environment across all N rates. In the 2006 irrigated environment corn yield loss was increased by decreasing N rate and increasing PA density. Maximum predicted yield loss at high PA densities in both 2005 environments was 20-54% while in 2006 dryland environment, maximum yield loss was 95% and in the irrigated environment was 62%. In general, soil moisture environment was more critical than N rate or PA density when determining potential corn yield. In the greenhouse study a factorial arrangement of two irrigation methods and five crop-weed combinations (corn, PA, GF, corn/PA, and corn/GF) was established with two replications and three runs conducted. Two plants were grown in 25.4 cm diameter PVC pipe cut into 91.5 cm lengths. Irrigation application method included a surface and subsurface application. Plants were harvested at the V10 corn growth stage. No differences were detected between irrigation methods with respect to above- or below ground biomass production. Corn aboveground biomass was decreased by the presence of corn or PA but not GF. Below ground biomass information was presented as column totals because species could not be separated. There was no impact on root to shoot ratio, total below ground biomass, rooting depth, or root area across the crop-weed combinations except for the GF monoculture columns which were lower than all other crop-weed combinations. Future research needs to examine the light interception of corn and PA when grown at different N rates along with examining the influence of surface and subsurface irrigation practices on crop weed interactions and weed seed germination in a field setting.

Marseilleviridae est une famille de virus géants isolés initialement à partir de prélèvements environnementaux, dont Marseillevirus est le membre fondateur. La présence des marseillevirus chez l’Homme a été démontrée dans quelques études. Les objectifs sont de mieux documenter la présence des marseillevirus chez l’Homme, de modéliser l’infection par Marseillevirus chez la souris, et enfin, de décrire les génomes des marseillevirus. Nous rapportons un cas d’infection par Marseillevirus chez une patiente atteinte d’un cancer des ganglions, soulevant la question d’un éventuel lien entre Marseillevirus et cancer, à l’instar de l’association existant entre d’autres virus et les cancers. L’infection des souris par Marseillevirus montre que celui-ci persiste un mois au niveau des «amygdales», confirmant le portage pharyngé chronique observé chez un deuxième patient. Enfin, nous identifions deux nouveaux groupes au sein de la famille, soulignant l’importante diversité génétique de la famille. / Marseilleviridae is a new family of giant viruses primarily isolated from environmental samples and whose Marseillevirus is the founding member. The presence of marseilleviruses in humans has been demonstrated in few studies. The aims are to better document the presence of marseilleviruses in humans, to develop a model of infection of mice with Marseillevirus, and to describe the genomes of marseilleviruses. We report a first caes of infection by Marseillevirus in apatient with a lymph nodes cancer, raising the question of a potential link between Marseillevirus and cancer, as the well established association between some viruses and cancers. The infection of miceshows that Marseillevirus persist one month in the “tonsils”, confirming the chronic pharyngeal carriage reported in a second patient. Finally, we identify two new subgroups in the family, highlighting the considerable genetic diversity of the family.