Loss of temporal structure of tropical soundscapes with intensifying land use in Borneo.

Conservation and sustainable management efforts in tropical forests often lack reliable, effective, and easily-communicated ways to measure the biodiversity status of a protected or managed landscape. The sounds that many tropical species make can be recorded by pre-programmed devices and analysed to yield measures of biodiversity. Interpreting the resulting soundscapes has developed along two paths: analysing the whole soundscape using acoustic indices, used as a proxy of biodiversity, or focusing on individual species that can be either manually or automatically recognized from the soundscape. Here we develop an intermediate approach to divide the soundscape into frequency categories belonging to broad taxonomic groups of vocalizing animals. While the method was unable to distinguish between amphibian and mammal communities, it was successful in assigning parts of the soundscape as likely produced by birds and insects. Applying the approach in Borneo revealed that, with increasing land use intensity, i) the spectral saturation of the soundscape, a proxy of species richness, loses dawn and dusk peaks, ii) bird acoustic communities lose recurrent diurnal patterns, becoming less synchronized across sites, and that iii) insect Soundscape Saturation increases at night. If soundscapes are partitioned similarly in different regions, our method could be used to bridge soundscape-level and individual-species level analyses. Regaining dawn and dusk peaks, the synchrony of bird acoustic communities, and losing nocturnal dominance of insect could be used as a set of simple indicators of tropical forest retaining high levels of biodiversity.

Increase in skin perfusion pressure after maggot debridement therapy for critical limb ischaemia.

Skin perfusion pressure (SPP) is the perfusion pressure at the skin level, and it can serve as an index of peripheral circulation in the skin and subcutaneous tissue. We report a 78-year-old man with critical limb ischaemia who, despite having undergone several catheter interventions, still had severe ulcers with exposed bone on his right foot. We performed transmetatarsal amputation. The tissue around the surgical site became necrotic several days later, and did not respond to conservative therapy. Therefore, we opted for maggot debridement therapy (MDT), given that maggots favour necrotic tissue. After the therapy, SPP around the ulcer increased from 12 to 54 mmHg on the dorsal aspect, and from 17 to 44 mmHg on the plantar aspect. Wound healing was successfully activated by MDT, leading to complete healing within 2.5 months after MDT. We believe that MDT probably contributed to increase the blood supply to the ischaemic wound.