Study of Damage Propagation at the Interface Localization-Delocalization Transition of the Confined Ising Model

The propagation of damage in a confined magnetic Ising film, with short range competing magnetic fields ($h$) acting at opposite walls, is studied by means of Monte Carlo simulations. Due to the presence of the fields, the film undergoes a wetting transition at a well defined critical temperature $T_w(h)$. In fact, the competing fields causes the occurrence of an interface between magnetic domains of different orientation. For $T T_w(h)$) such interface is bounded (unbounded) to the walls, while right at $T_w(h)$ the interface is essentially located at the center of the film. It is found that the spatio-temporal spreading of the damage becomes considerably enhanced by the presence of the interface, which act as a ''catalyst'' of the damage causing an enhancement of the total damaged area. The critical points for damage spreading are evaluated by extrapolation to the thermodynamic limit using a finite-size scaling approach. Furthermore, the wetting transition effectively shifts the location of the damage spreading critical points, as compared with the well known critical temperature of the order-disorder transition characteristic of the Ising model. Such a critical points are found to be placed within the non-wet phase.Comment: 22 pages, 13 figures include

Biology and conservation status of Piraja’s Lancehead Snake <i>Bothrops piraña</i> Amaral, 1923 (Serpentes: Viperidae), Brazil

The venomous snake Bothrops pirajai (Amaral, 1923) is endemic to Brazil. Despite being described almost a century ago, very little is known about this species, which has never been studied in situ. Here, we present new data on the biology and natural history of B. pirajai based on a review of existing museum specimens and a field study (1504 man hours) carried out throughout the species range. The distribution of B. pirajai was found to be restricted to the eastern Atlantic forest of the state of Bahia, Brazil, between Todosos Santos Bay, Itabuna and Ilhéus (12050’S-14050’S, 88-835 m). We recommend the species be uplisted to Endangered in the International Union for the Conservation of Nature’s global Red List of Threatened Species as its estimated extent of occurrence is under 5000km2. The effective conservation of B. pirajai will rely on addressing two key issues: improving our knowledge of the species and successfully mitigating habitat loss and fragmentation