Variable harlequin frogs Atelopus varius have declined significantly throughout their range as a result of infection with the fungal pathogen Batrachochytrium dendrobatidis (Bd). The Panama Amphibian Rescue and Conservation Project maintains an ex situ population of this Critically Endangered species. We conducted a release trial with surplus captive-bred A. varius individuals to improve our ability to monitor frog populations post-release, observe dispersal patterns after freeing them into the wild and learn about threats to released frogs, as well as to determine whether natural skin toxin defences of frogs could be restored inside mesocosms in the wild and to compare Bd dynamics in natural amphibian communities at the release site vs a non-release site. The 458 released frogs dispersed rapidly and were difficult to re-encounter unless they carried a radio transmitter. No frog was seen after 36 days following release. Thirty frogs were fitted with radio transmitters and only half were trackable by day 10. Tetrodotoxin was not detected in the skins of the frogs inside mesocosms for up to 79 days. Bd loads in other species present at sites were high prior to release and decreased over time in a pattern probably driven by weather. No differences were observed in Bd prevalence between the release and non-release sites. This trial showed that refinements of our methods and approaches are required to study captive Atelopus frogs released into wild conditions. We recommend continuing release trials of captive-bred frogs with post-release monitoring methods, using an adaptive management framework to advance the field of amphibian reintroduction ecology.

We present low-temperature inelastic neutron scattering spectra collected on two metal oxide nanoparticle systems, isostructural TiO2 rutile and SnO2 cassiterite, between 0-550 meV. Data were collected on samples with varying levels of water coverage, and in the case of SnO2, particles of different sizes. This study provides a comprehensive understanding of the structure and dynamics of the water confined on the surface of these particles. The translational movement of water confined on the surface of these nanoparticles is suppressed relative to that in ice-Ih and water molecules on the surface of rutile nanoparticles are more strongly restrained that molecules residing on the surface of cassiterite nanoparticles. The INS spectra also indicate that the hydrogen bond network within the hydration layers on rutile is more perturbed than for water on cassiterite. This result is indicative of stronger water-surface interactions between water on the rutile nanoparticles than for water confined on the surface of cassiterite nanoparticles. These differences are consistent with the recently reported differences in the surface energy of these two nanoparticle systems.

Two geographic information system (GIS) techniques for displaying, analyzing, and interpreting geophysical data were recently applied at two archaeological sites in northern New Zealand; a pre-European Maori pa (fortification), and a late nineteenth-century European fortification. A GIS was used to stretch and filter the conductivity data from the pa to accentuate subtle contrasts and clearly delineate boundaries between areas with contrasting conductivity readings. Magnetic susceptibility data and two different bands of conductivity data from the historic fort were used as input for a GIS-based unsupervised classification. The classification delineated five spatial entities, several of which corresponded to known archaeological features. The interpretability of the geophysical data in relation to conventional visual analysis of conductivity contour maps was enhanced through the use of the GIS procedures outlined.