Our Changing World for Thursday 27 May 2010
Tour of a Pathology Lab - Part 2
Jarratt Gould at the microscope, some agar plates (image: Simon Hoyle, Southlight), and Mackenzie Nicol in the Microbiology Department at Aotea Pathology.
In the second part of a tour of the laboratories at Wellington-based Aotea Pathology, Ruth Beran meets Mackenzie Nicol who takes her on a tour of the microbiology department, and Jarratt Gould who works in mycology.
The microbiology department has different benches which process, for example, medical specimens taken from people with bacteria or viruses affecting their urine or faeces, wound infections, genital diseases, or toenail fungi. Unlike some of the other sections in the laboratory, which are highly automated, this department is "hands on" - samples are often grown up and then analysed under the microscope to identify which organism is causing the illness, and then tested, for example against antibiotics, to determine how the patient can be treated.
Sweetwater Covenant, Chatham Island
The predator proof fence around the bush edge marks the Sweetwater Covenant on the Tuanui farm, and inside the fence the forest is regenerating quickly (images: A. Ballance)
Liz and Bruce Tuanui are Chatham Island farmers, conservationists and board members of the Chatham Island Taiko Trust. They have protected several important areas of forest on their farm with conservation covenants, and run a predator trapping programme across their entire farm - from coast to forest interior. The Awatotora Covenant, near the farmhouse, is now home to a growing population of parea, or Chatham pigeons, as well as Chatham Island tui, newly translocated from Rangatira Island (a 2-part story on the tui translocation featured in Our Changing World on 22 April and 29 April)
The Sweetwater Covenant lies at the end of the farm next to the Tuku Nature Reserve, which Bruce's parents gifted to the Crown. In 2006, with support from the Taiko Trust, a predator-proof fence was erected around the remnant forest and predators within the fenced were trapped and poisoned. The Tuku is the last known breeding site for taiko, one of New Zealand's rarest and most elusive seabirds. In an effort to restore populations of both taiko and Chatham petrels within the safe confines of the fence, nesting burrows have been built, and chicks are placed in the burrows and fed for the last few weeks before they fledge, in an effort to re-programme them to return to the reserve rather than the burrows where they hatched. Loud speaker systems play the calls of both taiko and Chatham petrels at night in an effort to attract other birds to the area.
The stick 'fence' across the burrow entrance is a simple way of knowing whether or not a bird has visited the burrow, as it gets knocked over when the bird enters. The speakers play Chatham petrel and taiko calls all night to attract passing birds (images: A. Ballance)
Supercritical Fluid Extraction
Have you ever wondered how decaffeinated coffee is made? Well, the process is called supercritical fluid extraction, and at IRL in Lower Hutt products are being extracted using that process on a daily basis.
A supercritical fluid is when a substance, such as a gas, is pushed above its critical temperature and pressure, allowing it to dissolve materials like a solvent and extract materials. Carbon dioxide is commonly used for supercritical fluid extraction, but IRL's Owen Catchpole explains to Ruth Beran why dimethyl ether is being used instead. He also demonstrates the mobile food-grade supercritical fluid extraction plant that IRL has developed and how it can be transported and then used in commercial laboratories all over New Zealand.
NZ Coastal Marine Invertebrates - New Book
Claire Ballance and Sue Hallas, book in hand, fossick for creatures such as top shells, fragile limpets and red bead anemones, all found on the underside of a single small boulder (images: A. Ballance)
Fossicking in rock pools at the beach has endless appeal for young and old, and is a great conversation starter. What exactly is that red squishy thing under the rock, and what sort of shell is that? Those burning questions can finally be answered, with Canterbury University Press having just published volume one of Steve de C. Cook's 'New Zealand Coastal Marine Invertebrates'. When companion volume 2 comes out (expected in 2012) it will be a complete guide to nearly 1500 species of coastal invertebrates. At 640 pages volume one is a bit hefty to take to the beach, but is a great reference book for the home or school library. Nonetheless, Alison Ballance drags a copy along to the beach to put it through its paces with her 10-year old niece Claire, and Nelsonian Sue Hallas who was intimately involved with the production of the book as copy editor.
For a simpler more beach-friendly guide to rock pools check out the new Northern and Southern Rocky Shore Guides, published by the Portobello Marine Laboratory.