background and aim . gingivitis is a reversible inflammatory reaction seen with various degrees in most individuals aged 17 to 22 years. the aim of this study was to compare the effects of two herbal extracts on streptococcus salivarius and streptococcus sanguis. materials and methods . aqueous alcoholic root extracts of malva sylvestris and salvadora persica were prepared and tested on pseudom...

We propose a new dynamical model for capture of irregular moons which identifies chaos as the essential feature responsible for initial temporary gravitational trapping within a planet’s Hill sphere. The key point is that incoming potential satellites get trapped in chaotic orbits close to “sticky” KAM tori in the neighbourhood of the planet, possibly for very long times, so that the chaotic la...

The surfaces of Jupiter’s moons are profoundly weathered by jovian charged particle and solar ultraviolet (UV) irradiation. Although early observations of the Galilean satellites suggested that their reflectance spectra were modified by energetic particles, it has only recently been shown quantitatively that radiolysis and photolysis, the chemical alteration of a surface by charge-particles and...

Jupiter and Saturn have extended, nearly toroidal atmospheres composed of material ejected from their moons or rings. Here we suggest that similar atmospheres must exist around giant extrasolar planets and might be observable in a transit of the parent star. Observation of such an atmosphere would be a marker for the presence of orbiting debris in the form of rings or moons that might otherwise...

solar perturbations dominate. Since the detailed mass distribution within the asteroid is relatively unimportant in We introduce a new analytic method for treating the orbital motions of objects about asteroids and planets. For an asteroid this regime, orbits about one asteroid are similar to those following a circular path around the Sun, we rewrite Jacobi’s about another as long as the eccent...