Irregular satellites of Jupiter: Three-dimensional study of binary-asteroid captures

Among the hidden pieces of the giant puzzle, which is our Solar system, the origins of irregularsatellites of the giant planets stand to be explained, while the origins of regular satellites arewell explained by the in situ formation model through matter accretion. Once they are notlocally formed, the most acceptable theory predicts that they had been formed elsewhere andbecame captured later, most likely during the last stage of planet formation. However, underthe restricted three-body problem theory, captures are temporary and there is still no assistedcapture mechanism which is well established. In a previous work, we showed that the capturemechanism of a binary asteroid under the co-planar four-body scenario yielded permanentcaptured objects with an orbital shape which is very similar to those of the actual progradeirregular Jovian satellites. By extending our previous study to a 3D case, here we demonstratethat the capture mechanism of a binary asteroid can produce permanent captures of objects byitself which have very similar orbits to irregular Jovian satellites. Some of the captured objectswithout aid of gas drag or other mechanisms present a triplet: semi-major axis, eccentricityand inclination, which is comparable to the already known irregular Jovian objects. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Molecular and serological detection of tick-borne pathogens in dogs from an area endemic for Leishmania infantum in Mato Grosso do Sul, Brazil

Patógenos transmitidos por carrapatos atingem uma variedade de hospedeiros vertebrados. Para identificar os agentes patogênicos transmitidos por carrapatos entre cães soropositivos para Leishmania infantum no município Campo Grande-MS, foi realizado um estudo sorológico e molecular para a detecção de Ehrlichia canis, Anaplasma platys e Babesia vogeli em 60 amostras de soro e baço, respectivamente. Adicionalmente, foi realizado o diagnóstico confirmatório de L. infantum por meio de técnicas sorológicas e moleculares. Também foi realizado o alinhamento e análise filogenética das sequências para indicar a identidade das espécies de parasitas que infectam esses animais. Anticorpos IgG anti-Ehrlichia spp., anti-B. vogeli e anti-L. infantum foram detectados em 39 (65%), 49 (81,6%) e 60 (100%) dos cães amostrados, respectivamente. Vinte e sete (45%), cinquenta e quatro (90%), cinquenta e três (88,3%), dois (3,3%) e um (1,6%) cães mostraram-se positivos na PCR para E. canis, Leishmania spp., Leishmania donovani complex, Babesia sp. e Anaplasma sp., respectivamente. Após o seqüenciamento, os amplicons mostraram 99% de similaridade com isolados de E. canis, B. vogeli e A. platys e Leishmania chagasi. Os resultados deste estudo indicaram que os cães soropositivos para L. infantum de Campo Grande, MS, são expostos a vários agentes transmitidos por carrapatos, e, portanto, devem ser incluídos no diagnóstico diferencial em cães com suspeita clínica de leishmaniose.

Molecular and parasitological detection of Leishmania spp. in a dipteran of the species Tabanus importunus

A leishmaniose é uma importante zoonose, de caráter crônico, causada por protozoários do gênero Leishmania spp. Esta protozoose tem como principal vetor os flebotomíneos, sendo que, no Brasil, o Lutzomyia longipalpis é a principal espécie incriminada na transmissão da leishmaniose Visceral Americana. A presença do ácido desoxirribonucleico (DNA) do parasito em ectoparasitos, como carrapatos e pulgas, tem gerado especulações quanto a existência de novos vetores no ciclo da leishmaniose. Foi objetivo deste estudo relatar a detecção molecular de Leishmania spp. em uma mutuca da espécie Tabanus importunus que parasitava um cão oligossintomático infectado por Leishmania spp. A análise molecular amplificou o DNA do protozoário na cabeça, na região torácica e no abdomen do tabanídeo, resultando como positivo para complexo Leishmania. Este é o primeiro relato da presença de DNA de Leishmania spp. em insetos dipteros da espécie T. importunus.

ORBITAL PERTURBATIONS OF THE GALILEAN SATELLITES DURING PLANETARY ENCOUNTERS

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

Serology, isolation, and molecular detection of Leptospira spp. from the tissues and blood of rats captured in a wild animal preservation centre in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A comparison of microbiological and molecular detection of vaginal Lactobacillus spp. between mares and women

A possible explanation for endometritis in mares is ascendant contamination from the vagina. The presence of Lactobacillus spp. is considered to be important in women for a healthy vaginal environment; however, there are few studies in mares related to the presence of Lactobacillus in the vaginal flora of healthy mares. The present work aims to determine the occurrence of Lactobacillus spp. in the vaginal micro-environment of mares. A total of 35 crossbred multiparous mares, aged between 4 and 12 years, with no history of reproductive problems and with healthy reproductive tracts, were used. Two vaginal swabs were obtained from the mares during estrus for Lactobacillus isolation and PCR evaluation. Ten human female volunteers, aged between 24 and 35 years, sexually active, with no history of gynecological diseases and treatments in the past two years were used. Lactobacillus spp. were isolated from 5.7% of the mares' vaginal samples and from 90% of the women's vaginal samples. Lactobacillus DNA was detected by PCR in 22.9% of the mares' vaginal samples and in all of the vaginal samples from the healthy women. The primers used here were demonstrated to have in silico specificity for the detection of L. equi (AB425924.1), L. pantheris (DQ471798.1) and L. mucosae (DQ471799.1), but they did not anneal on Enterococcus faecalis (EU887827.1) or E. faecium (EU887814.1). In conclusion, this study showed a low occurrence of Lactobacillus spp. in mares, suggesting that this bacterium may not play a fundamental role in the equilibrium of the vaginal micro- environment of normal mares.

Production of the Quinone-Methide Triterpene Maytenin by In Vitro Adventitious Roots of Peritassa campestris (Cambess.) ACSm. (Celastraceae) and Rapid Detection and Identification by APCI-IT-MS/MS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Long-term dynamics of Methone, Anthe and Pallene

We numerically investigate the long-term dynamics of the Saturn's small satellites Methone (S/2004 S1), Anthe (S/2007 S4) and Pallene (S/2004 S2). In our numerical integrations, these satellites are disturbed by non-spherical shape of Saturn and the six nearest regular satellites. The stability of the small bodies is studied here by analyzing long-term evolution of their orbital elements.We show that long-term evolution of Pallene is dictated by a quasi secular resonance involving the ascending nodes (12) and longitudes of pericentric distances (pi) of Mimas (subscript 1) and Pallene (subscript 2), which critical argument is pi(2) - pi(1) - Omega(1) + Omega(2) Long-term orbital evolution of Methone and Anthe are probably chaotic since: i) their orbits randomly cross the orbit of Mimas in time scales of thousands years); ii) long-term numerical simulations involving both small satellites are strongly affected by small changes in the initial conditions.

Development of biomimetic sensor for fast and sensitive detection of Norfloxacin

A biomimetic sensor is proposed as a promising new analytical method for determination of norfloxacin (NF) in pharmaceuticals. The sensor was prepared by modifying a glassy carbon electrode surface with a Nafion® membrane doped with poly(copper phthalocyanine) complex [poly-CuPc]. Amperometric measurements carried out with the sensor under an applied potential of -0.05 V vs Ag|AgCl in 0.1 mol L-1 acetic acid containing 1.5 × 10-3 mol L-1 hydrogen peroxide showed a linear response range from 2.0 × 10-4 to 1.2 × 10-3 mol L-1. Selectivity and interference studies were also performed. A sensor response mechanism is proposed, based on the experimental evidence. Recovery studies were carried out using environmental samples, in order to evaluate the sensor’s potential for use with these sample classes. Finally, sensor performance was evaluated using analyses of commercial formulations.

Molecular and serological detection of Babesia Bovis and Babesia Bigemina in cattle in the Rio de Janeiro, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Exploring S-type orbits in the Pluto-Charon binary system

This work generates, through a sample of numerical simulations of the restricted three-body problem, diagrams of semimajor axis and eccentricity which defines stable and unstable zones for particles in S-type orbits around Pluto and Charon. Since we consider initial conditions with 0 <= e <= 0.99, we found several new stable regions. We also identified the nature of each one of these newly found stable regions. They are all associated to families of periodic orbits derived from the planar circular restricted three-body problem. We have shown that a possible eccentricity of the Pluto-Charon system slightly reduces, but does not destroy, any of the stable regions.

On the dynamics of some resonances of Phobos in the future

A probable capture of Phobos into an interesting resonance was presented in our previous work. With a simple model, considering Mars in a Keplerian and circular orbit, it was shown that once captured in the resonance, the inclination of the satellite reaches very high values. Here, the integrations are extended to much longer times and escape situations are analyzed. These escapes are due to the interaction of new additional resonances, which appear as the inclination starts to increase reaching some specific values. Compared to classical capture in mean motion resonances, we see some interesting differences in this problem. We also include the effect of Mars' eccentricity in the process of the capture. The role played by this eccentricity becomes important, particularly when Phobos encounters a double resonance at a approximate to 2.619R(M). Planetary perturbations acting on Mars and variation of its equator are also included. In general, some possible scenarios of the future of Phobos are presented.

Effect of Jupiter's mass growth on satellite capture

We study the effects of Jupiter mass growth in order to permanently capture prograde satellites. Adopting the restricted three-body problem, Sun-Jupiter-Particle, we performed numerical simulations backward in time while considering the decrease in Jupiter's mass. We considered the particle's initial conditions to be prograde, at pericenter, in the region 100R(4) <= a <= 400R(4) and 0 <= e <= 0.5. The results give Jupiter's mass at the moment when the particle escapes from the planet. Such values give an indication of the conditions that are necessary for capture. An analysis of these results shows that prograde satellite capture is more complex than a retrograde one. It occurs in a two-step process. First, when the particles get inside about 0.85R(Hill) (Hills' radius), they become weakly bound to Jupiter. Then, they keep migrating toward the planet with a strong decrease in eccentricity, while the planet is growing. The radial oscillation of the particles reduces significantly when they reach a radial distance that is less than about 0.45R(Hill) from the planet. Three-dimensional simulations for the known prograde satellites of Jupiter were performed. The results indicate that Leda, Himalia, Lysithea, and Elara could have been permanently captured when Jupiter had between 50% and 60% of its present mass.

The effect of Jupiter's mass growth on satellite capture - Retrograde case

Gravitational capture can be used to explain the existence of the irregular satellites of giants planets. However, it is only the first step since the gravitational capture is temporary. Therefore, some kind of non-conservative effect is necessary to to turn the temporary capture into a permanent one. In the present work we study the effects of Jupiter mass growth for the permanent capture of retrograde satellites. An analysis of the zero velocity curves at the Lagrangian point L-1 indicates that mass accretion provides an increase of the confinement region ( delimited by the zero velocity curve, where particles cannot escape from the planet) favoring permanent captures. Adopting the restricted three-body problem, Sun-Jupiter-Particle, we performed numerical simulations backward in time considering the decrease of M-4. We considered initial conditions of the particles to be retrograde, at pericenter, in the region 100 R-4 less than or equal to a less than or equal to 400 R-4 and 0 less than or equal to e < 0.5. The results give Jupiter's mass at the moment when the particle escapes from the planet. Such values are an indication of the necessary conditions that could provide capture. An analysis of these results shows that retrograde satellites would be captured as soon as they get inside the Hills' radius and after that they keep migrating toward the planet while it is growing. For the region where the orbits of the four old retrograde satellites of Jupiter ( Ananke, Carme, Pasiphae and Sinope) are located we found that such satellites could have been permanently captured when Jupiter had between 62% and 93% of its present mass.

Distant stable direct orbits around the Moon

In the present work we explore regions of distant direct stable orbits around the Moon. First, the location and size of apparently stable regions are searched for numerically, adopting the approach of temporary capture time presented in Vieira Neto & Winter (2001). The study is made in the framework of the planar, circular, restricted three-body problem, Earth-Moon-particle. Regions of the initial condition space whose trajectories are apparently stable are determined. The criterion adopted was that the trajectories do not escape from the Moon during an integration period of 10(4) days. Using Poincare surface of sections the reason for the existence of the two stable regions found is studied. The stability of such regions proved to be due to two families of simple periodic orbits, h1 and h2, and the associated quasi-periodic orbits that oscillate around them. The robustness of the stability of the larger region, h2, is tested with the inclusion of the solar perturbation. The size of the region decreases, but it is still significant in size and can be useful in spacecraft missions.