Braneworld solutions for F(R) models with non-constant curvature

This work deal with braneworld scenarios with generalized gravity. We investigate models where the potential of the scalar field is polynomial or nonpolynomial. We obtain exact and approximated solutions for the scalar field, warp factor and energy density, in the complex scenario with no restriction on the scalar curvature. In particular, we describe the case where the brane may split, engendering internal structure, with the splitting caused by the same parameter that controls deviation from standard gravity.Comment: 9 pages, 7 figures; new versio

A revision of the South American snake genus Thamnodynastes Wagler, 1830 (Serpentes, Colubridae, Tachymenini): I. Two new species of Thamnodynastes from Central Brazil and adjacent areas, with a redefinition of and neotype designation for Thamnodynastes pallidus (Linnaeus, 1758)

Two new species of Thamnodynastes whose ranges are entirely or largely in Brazil are described. Thamnodynastes pallidus, one of the most easily identified species of the genus, is redefined and a neotype is designated, and Coluber strigilis Thunberg is placed in its synonymy, thus clarifying an enduring state of confusion in the taxonomy of this genus