Tag Archives: pigment

OPAL reactor fingerprints Aboriginal ochre

A Flinders University chemist is using Australia’s OPAL research reactor at Lucas Heights in Sydney to investigate ancient Aboriginal Australian society.

Using the technique called neutron activation analysis, Dr Rachel Popelka-Filcoff can “geochemically fingerprint” Aboriginal ochre pigments from different locations, archaeological sites and artefacts.

Applying nuclear power to research
Rachel Popelka-Filcoff can trace the cultural use of ochre using Australia’s research reactor. Credit: Ashton Claridge, Flinders Media
As the geochemical composition of ochre varies with location, she can correlate each sample with its site of origin, gaining information on cultural practices, travel and exchange patterns, and the relationship of Aboriginal people to the landscape. “Ochre pigments are highly significant in Aboriginal culture,” says Rachel. “Cultural expression often requires a specific pigment. Applying ochre to an object such as a spear can transform both its colour and its cultural meaning.”

Dr Roman Dronov, also from Flinders, is using the reactor to study the formation of bacterial protein layers. He is applying what he finds to constructing a new type of biosensor based on these layers and porous silicon. These highly sensitive devices can rapidly detect trace amounts of molecules, such as environmental poisons and markers of disease—a great improvement on traditional analytical methods.
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Unmasking melanoma early

There’s a new diagnostic tool being developed to target melanoma, the deadly form of skin cancer with which more than 10,000 Australians are diagnosed each year.

Unmasking melanoma early
The red arrows show a melanoma tumour. The PET/CT scan on the right shows how the MEL050 tracer highlights the location, size and spread of melanoma. Credit: Peter MacCallum Cancer Centre

It’s a chemical compound designed to highlight small traces of these cancer cells in the body.

Melanoma occurs when the cells that make melanin, the dark pigment normally found in the skin, become cancerous. Melanoma cells often spread elsewhere in the body before the primary tumours are detected and removed surgically. Clusters of these melanoma cells can be hard to detect before they grow into tumours by which time they are often incurable.
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