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Our Changing World for Thursday 19 April 2012

  • Full-Colour X-Rays

    9:46 PM.A full-colour X-ray scanner, initially developed for high-energy physics, could change medical imaging Audio

  • Whio Forever - Blue Duck Conservation

    9:06 PM.The whio population on the Mangatepopo River is thriving due to stoat trapping and perfect water flow Audio

'Whio Forever' – Blue Duck Conservation

Pair of whio or blue duck in a fast-flowing river, and with small chicks

A pair of whio, or blue duck (left), and with a clutch of small chicks (right) - chicks are able to swim and feed themselves as soon as they have hatched (images: Bubs Smith)

Whio, or blue duck, live in fast-flowing streams and rivers, usually in areas of remote native forest. This whistling, white-water specialist is found only in New Zealand, and is threatened, with a national population of just a few thousand birds. The Department of Conservation and its Whio Forever partner, Genesis Energy, are working ‘to secure whio populations to a minimum of 400 pairs at eight 'security sites' throughout New Zealand by 2014’.

In this story Alison Ballance gets wet feet on a trip down the Mangatepopo River, in the central North Island, with the Department of Conservation’s Bubs Smith and Genesis Energy’s Cam Speedy. The Mangatepopo River is part of the Tongariro Forest Security Site for whio, along with the Whanganui and Whakapapa rivers. Since 2003 the number of whio pairs on the Mangatepopo River has climbed from 4 to 20, average territory size for each pair has shrunk from 1575 metres of river to 315 metres, and in the 2011/2 breeding season 41 chicks were fledged on the river. This success is due to intensive stoat trapping down and alongside the river, regular 1080 drops in the surrounding Tongariro Forest, clean productive water, and a managed water flow regime that is optimal for whio and their insect prey. The water flow is 500 litres per second, which was determined during the reconsenting process for the Tongariro Power Scheme in 2002.

whio

Whio Nic and her partner swimming nearby as Alison Ballance interviews Cam Speedy (left) , and Bubs Smith and Cam Speedy (right) (images: Bubs Smith and Alison Ballance)

Full-colour X-rays

Physicists have known for a long time that X-rays change colour as they pass through tissue, but the detectors in conventional medical X-ray scanners cannot detect this change in wavelength. The University of Canterbury is a partner in a collaboration between CERN and 17 other organisations, which has developed a new generation of detectors, the Medipix chip, to produce full-colour X-ray images. Although these detectors were initially developed for use in high-energy physics, they could add a new tool to medical imaging.

Anthony Butler is a radiologist at Christchurch Hospital, but he’s also the director of the Centre for Bioengineering at the University of Otago, in Christchurch, and a researcher at the University of Canterbury’s HIT lab. He was involved in the development of the detectors, particularly their application in medical diagnostics, and in this interview he discusses the potential of this new technology.