Efeitos de torques gravitacionais na dinâmica de asteróides múltiplos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Encontros próximos: captura gravitacional temporária e esfera de influência

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Satélites irregulares de Júpiter: análise da captura de asteróides binários

Pós-graduação em Física - FEG

Origem dos satélites irregulares de Júpiter: captura de asteroides binários primordiais

Pós-graduação em Física - FEG

Doença de Jorge Lobo: estudo histopatológico retrospectivo de casos registrados no serviço de dermatologia da Universidade Federal do Pará no período de 1967 a 2009

Doença de Jorge Lobo (DJL) ou lacaziose é infecção crônica granulomatosa da pele e tecido subcutâneo causada pelo fungo Lacazia loboi. As lesões cutâneas em geral são polimorfas, sendo mais comum o tipo nodular de aspecto queloidiano envolvendo principalmente pavilhão auricular e membros. O exame histopatológico constitui o padrão ouro para o diagnóstico. São escassos os estudos sobre correlação clinicopatológica nesta doença. O presente trabalho apresenta como objetivo estudar casos diagnosticados como DJL pelo laboratório de dermatopatologia do Serviço de Dermatologia da Universidade Federal do Pará, no período de 1967 a 2009. Foi realizada a revisão dos prontuários médicos e estudadas as características demográficas, histológicas, clínicas e localização das lesões. 59 biópsias de 45 pacientes foram avaliadas. A amostra foi composta de 37 homens e oito mulheres, com média de idade de 50 anos. A maioria dos pacientes era lavrador (55%), dos quais 93% eram do sexo masculino. O aspecto queloidiano correspondeu a 59% das lesões. Com menor freqüência foram observadas lesões verruciformes (8%), placa (3%), gomosa (1%) e lesão macular hipercrômica (1%). A maioria das lesões estava localizada nos membros inferiores (56%). Histopatologicamente, a camada córnea encontrava-se hiperceratósica em 71% das biópsias, com paraceratose em 37% e ortoceratose em 50%. A eliminação transepidérmica (ETE) do parasitas foi observada em 36% dos casos e nestes, a hiperceratose estava presente em 95% (p = 0,0121) e a paraceratose em 90% (p< 0,0001). A epiderme apresentava aspecto hiperplásico em 58%, atrófica em 29%, normal em 12% e ulcerada em 8%. Nos casos em que houve ETE a epiderme apresentava-se hiperplásica em 86% (p = 0,0054). Observou-se presença de parasitas na epiderme em 30%, das quais 89% apresentavam ETE associada (p< 0,0001). Não houve relação estatisticamente significante entre a ocorrência de ETE e o aspecto clínico da lesão (p = 0,4231). Linfócitos, macrófagos e células gigantes do tipo corpo estranho foram as células predominantes do infiltrado (100% dos casos). Plasmócitos foram observados em 35%, neutrófilos em 15% e eosinófilos em 11% dos casos. Houve relação estatisticamente significante entre a ocorrência de ETE e presença de neutrófilos no infiltrado (p = 0,0016). Em 10% esteve presente reação exsudativa e 11% áreas de necrose isoladas. Células gigantes do tipo Langhans foram observadas em 59% das biópsias, corpos asteróides em 5%, células pseudo-Gaucher em 69% e fibrose em 96%. O infiltrado se estendia à derme reticular em todos os casos e para a derme profunda em 88% (52/59). Em 10% (6/59) dos casos houve disseminação do infiltrado para a gordura subcutânea, com encontro do parasita em um caso. Quanto à distribuição por idade, sexo e profissão dos pacientes, os dados foram superponíveis aos da literatura. A análise dos resultados, portanto, permitiu avaliar o perfil epidemiológico, clínico e histopatológico da doença, que diferiram, em alguns aspectos, dos achados classicamente descritos na literatura, especialmente em relação às características da epiderme, infiltrado inflamatório e localização das lesões.

Avaliação ultrassonográfica do bulbo ocular em cães submetidos à facoemulsificação com ou sem implante de lente intraocular

This study aimed to describe and compare the ultrasonographic alterations in dogs' eyes submitted to facectomy with or without intraocular lens implant (IOL), to assist in the diagnosis of possible alterations related to the surgical procedure and IOL implantation. Nineteen dogs with cataract (21 eyes) were submitted to phacoemulsification and late postoperative evaluation (at five years). The animals were initially submitted to complete ophthalmological exams which preceded the sonogram. Dogs were divided in three groups: (CA) aphakic dogs (n= 11); (PP) pseudophakic dogs with implantation of two IOLs in piggyback (n=5) and (PL) pseudophakic dogs with implantation of a veterinary IOL (n = 5). The ultrasound was carried under the administration of a topic local anesthetic, with a multi frequency linear transducer of 10 MHz. Biometric eye measurements were also performed. The clinical alterations observed were IOL dislocation, retinal detachment, asteroid hyalosis, and vitreous degeneration. Ultrasound examination was an excellent diagnostic tool, as it was possible to confirm and classify these changes. The piggyback implant reduced the measurements between the ciliary body and the vitreous chamber obtained from the ocular biometry when compared to other usual procedures, with no difference between the axial length and the anterior chamber.

ORBITAL PERTURBATIONS OF THE GALILEAN SATELLITES DURING PLANETARY ENCOUNTERS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dynamical evolution of V-type asteroids in the central main belt

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

3D stability orbits close to 433 Eros using an effective polyhedral model method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

PECULIAR EUPHROSYNE

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo preliminar do potencial de alguns asteroides

A survey we conducted, and bring expressed in this text is a preliminary study on the shape of asteroids and allowed us to understand a little more the dynamics around these bodies, in order that the images we have of asteroids are the most irregular possible. In this work, the asteroid is modeled by the method of the polyhedron, which provides a very good accuracy of the irregular shape of the body. Through study of models for non-spherical gravitational potential bodies, implementation of computational algorithms and numerical simulations a preliminary analysis was performed in relation to the shape of asteroids 4179 Toutatis, 6489 Golevka, 2063 Bacchus, 1620 Geographos and 1998 ML14, as well as regions of stability instability, we compute the coefficients of the gravitational potential. The work not only enables expansion for the case of asteroids, but also for other non-spherical bodies, contributing to the development of targeted studies the origin and evolution of the solar system, and perhaps the origin of the earth, and new technologies for modeling and mapping of non-spherical bodies. The main results were obtained by analyzing the graphics format and planning of asteroids, which confirmed how these bodies are irregular and show how distribution of non-homogeneous mass. Observe the behavior of the curves of zero velocity and equipotential curves as well as their respective surfaces. Also, compute some values of the gravitational potential and the spherical harmonic coefficients of each object. Furthermore, we find possible equilibrium points of asteroids except 4179 Toutatis, and analyze its stability

Stable retrograde orbits around the triple system 2001 SN263

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Regiões de estabilidade no ambiente de um sistema de asteroide triplo

This work was developed from the study by Araujo, R.A.N. et al. Stability regions around the components of the triple system 2001 SN263. (Monthly Notices Of The Royal Astronomical Society, 2012, v. 423(4), 3058-3073 p.) where it was studied the stable and unstable regions system (2001 SN263), which is a triple asteroid system, and these are celestial orbiting our sun. Being close to the Earth is characterized as NEA (Near-Earth Asteroids), asteroids and which periodically approach the Earth's orbit, given that there is great interest in the study and exploitation of these objects, it is the key can carry features that contribute to better understand the process of formation of our solar system. Study the dynamics of bodies that govern those systems proves to be greatly attractive because of the mutual gravitational perturbation of bodies and also by external disturbances. Recently, NEA 2001 SN263 was chosen as a target of Aster mission where a probe is sent for this triple system, appearing therefore the need for obtaining information for characterizing stable regions internal and external to the system, with respect to the effects of radiation pressure. First, this study demonstrated that the integrator used showed satisfactory results of the orbital evolution of bodies in accordance with previous studies and also the characterization of stable and unstable regions brought similar results to the study by Araujo et al. (2012). From these results it was possible to carry out the implementation of the radiation pressure in the system in 2001 SN263, in a region close to the central body, where the simulations were carried out, which brought as a result that the regions before being characterized as stable in unstable true for small particles size from 1 to 5 micrometers. So the next orbital region to the central body and the ... ( Complete abstract click electronic access below)

Regiões de estabilidade no ambiente de um sistema de asteroide triplo

This work was developed from the study by Araujo, R.A.N. et al. Stability regions around the components of the triple system 2001 SN263. (Monthly Notices Of The Royal Astronomical Society, 2012, v. 423(4), 3058-3073 p.) where it was studied the stable and unstable regions system (2001 SN263), which is a triple asteroid system, and these are celestial orbiting our sun. Being close to the Earth is characterized as NEA (Near-Earth Asteroids), asteroids and which periodically approach the Earth's orbit, given that there is great interest in the study and exploitation of these objects, it is the key can carry features that contribute to better understand the process of formation of our solar system. Study the dynamics of bodies that govern those systems proves to be greatly attractive because of the mutual gravitational perturbation of bodies and also by external disturbances. Recently, NEA 2001 SN263 was chosen as a target of Aster mission where a probe is sent for this triple system, appearing therefore the need for obtaining information for characterizing stable regions internal and external to the system, with respect to the effects of radiation pressure. First, this study demonstrated that the integrator used showed satisfactory results of the orbital evolution of bodies in accordance with previous studies and also the characterization of stable and unstable regions brought similar results to the study by Araujo et al. (2012). From these results it was possible to carry out the implementation of the radiation pressure in the system in 2001 SN263, in a region close to the central body, where the simulations were carried out, which brought as a result that the regions before being characterized as stable in unstable true for small particles size from 1 to 5 micrometers. So the next orbital region to the central body and the ... ( Complete abstract click electronic access below)

The remarkable solar twin HIP 56948: a prime target in the quest for other Earths

Context. The Sun shows abundance anomalies relative to most solar twins. If the abundance peculiarities are due to the formation of inner rocky planets, that would mean that only a small fraction of solar type stars may host terrestrial planets. Aims. In this work we study HIP 56948, the best solar twin known to date, to determine with an unparalleled precision how similar it is to the Sun in its physical properties, chemical composition and planet architecture. We explore whether the abundances anomalies may be due to pollution from stellar ejecta or to terrestrial planet formation. Methods. We perform a differential abundance analysis (both in LTE and NLTE) using high resolution (R similar to 100 000) high S/N (600-650) Keck HIRES spectra of the Sun (as reflected from the asteroid Ceres) and HIP 56948. We use precise radial velocity data from the McDonald and Keck observatories to search for planets around this star. Results. We achieve a precision of sigma less than or similar to 0.003 dex for several elements. Including errors in stellar parameters the total uncertainty is as low as sigma similar or equal to 0.005 dex (1%), which is unprecedented in elemental abundance studies. The similarities between HIP 56948 and the Sun are astonishing. HIP 56948 is only 17 +/- 7 K hotter than the Sun, and log g, [Fe/H] and microturbulence velocity are only +0.02 +/- 0.02 dex, +0.02 +/- 0.01 dex and +0.01 +/- 0.01 km s(-1) higher than solar, respectively. Our precise stellar parameters and a differential isochrone analysis shows that HIP 56948 has a mass of 1.02 +/- 0.02 M-circle dot and that it is similar to 1 Gyr younger than the Sun, as constrained by isochrones, chromospheric activity, Li and rotation. Both stars show a chemical abundance pattern that differs from most solar twins, but the refractory elements (those with condensation temperature T-cond greater than or similar to 1000 K) are slightly (similar to 0.01 dex) more depleted in the Sun than in HIP 56948. The trend with T-cond in differential abundances (twins -HIP 56948) can be reproduced very well by adding similar to 3 M-circle plus of a mix of Earth and meteoritic material, to the convection zone of HIP 56948. The element-to-element scatter of the Earth/meteoritic mix for the case of hypothetical rocky planets around HIP 56948 is only 0.0047 dex. From our radial velocity monitoring we find no indications of giant planets interior to or within the habitable zone of HIP 56948. Conclusions. We conclude that HIP 56948 is an excellent candidate to host a planetary system like our own, including the possible presence of inner terrestrial planets. Its striking similarity to the Sun and its mature age makes HIP 56948 a prime target in the quest for other Earths and SETI endeavors.