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A round-up of the latest science and news from Australasia.

Vitamin Deficiency Doubles Schizophrenia Risk

By Stephen Luntz

Important evidence has firmed up the suspected link between vitamin D deficiency and schizophrenia.

Babies in Denmark routinely have blood samples taken at birth, and analysis of these published in the Archives of General Psychiatry shows that those who were deficient in vitamin D have twice the rate of schizophrenia as adults.

The finding is far from a surprise. Evidence for connections between vitamin D deficiency in the latter months of pregnancy and increased risk of schizophrenia has been growing for many years (AS, July 2005, pp.35–38).

Fossilised Stromatolites Push Back Date for the Great Oxidation Event

These fossilised stromatolites may have been producing oxygen 270 million years

These fossilised stromatolites may have been producing oxygen 270 million years earlier than previously accepted. Photo: David Flannery

By Stephen Luntz

The fossilised stromatolites of the Pilbara region are among the oldest evidence for life we know. Now it appears some are even older than first thought, possibly pushing back the date at which oxygen-forming species appeared by 270 million years.

Between 2.45 and 2.32 billion years ago the Earth experienced the Great Oxidation Event, in which the atmosphere first gained a high oxygen content. While this is accepted, there is much debate about what happened earlier.

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By Stephen Luntz

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Tanning Risk Starts Young

sunbed

Sunbeds caused about three-quarters of melanomas in sunbed users under the age of 30.

By Stephen Luntz

The suspected risk of early melanoma posed by sunbeds has been confirmed.

A study has found that sunbed usage raises the risk of melanoma among 18–39-year-olds by 41%, and doubles the risk for those who start before they are 20.

“Research into the effects of sunbeds was considered sufficient last year for the International Agency for Research on Cancer to conclude that the risk of developing melanoma was increased by sunbed use,” says University of Sydney epidemiologist Prof Bruce Armstrong. Logically it might be expected that early use would create an increased risk, but this is the first time a study has confirmed this.

Anti-freeze Venom

By Stephen Luntz

Most venoms don’t work at very cold temperatures, which makes the poison produced by the Antarctic octopus particularly interesting.

The idea of putting animal venoms to use in the production of drugs, particularly painkillers, is not new (AS, Jan/Feb 2010, p.39). However, most venoms don’t work at very cold temperatures, which makes the poison produced by the Antarctic octopus particularly interesting.

Parasitic Wasp to NZ’s Rescue

The gum leaf skeletoniser larvae leave just the skeleton of eucalyptus leaves.

The gum leaf skeletoniser larvae leave just the skeleton of eucalyptus leaves.

By Stephen Luntz

A Tasmanian parasitic wasp (Cotesia urabae) has been approved as a biological control for a less appreciated import to New Zealand: the gum-leaf skeletoniser (Uraba lugens).

As the name suggests, the skeletoniser, a sort of hairy caterpillar, strips gum leaves to their veins and oil glands. Once older, it eats the entire leaf. Although there have been occasional large outbreaks of the skeletoniser in Australia, it is generally kept under control by various parasitic wasps, predatory insects and spiders.

Australia’s Scientific Illiteracy

By Stephen Luntz

A study of the public’s understanding of science has revealed how little many Australians know about the basics.

The most positive spin that the authors could put on their findings was that we were doing better than Americans.

The Federation of Australian Scientific and Technological Societies and the Australian Academy of Science polled 1515 people in July. Among their findings were:

• almost one-third believed that humans and dinosaurs coexisted;

• one-quarter did not think that humans were influencing the evolution of other species; and

• 39% did not know that it takes a year for the Earth to orbit the Sun.

Christchurch’s Unknown Fault

By Stephen Luntz

The earthquake that caused billions of dollars of damage to Christchurch, including to the University of Canterbury, occurred on a previously unknown fault line.

If that is not enough to cause alarm to those who thought their houses were safe, the head of the University’s Geology Department, A/Prof Tim Davies, says that most earthquakes occur on fault lines that were unknown previously.

“New Zealand is on an interplate margin,” Davies says. “Any active plate boundary will have very high stresses, with motion taking place along the cracks.

Eye of the Spider

Jumping spiders get surprisingly good vision from their smaller eyes.

Jumping spiders get surprisingly good vision from their smaller eyes.

By Stephen Luntz

he visual systems of jumping spiders are even more extraordinary than previously realised, according to a new study that has extracted remarkable precision from very small eyes.

Jumping spiders have four pairs of eyes, but one is vestigial. Another pair is very large relative to the spider, and provides remarkable vision while the two smaller pairs were thought to be simply used as motion sensors.

However, Macquarie University PhD student Daniel Zurek has overthrown this idea by placing removable dental silicone over the main and rear eyes of 52 jumping spiders (Servaea vestita) while leaving the forward-facing anterior lateral eyes uncovered. Zurek then showed the spiders tethered live house flies and dots moving on a screen.

Herpes Infection Route Revealed

By Stephen Luntz

University of Sydney researchers have found a piece in the puzzle explaining how the herpes simplex virus (HSV) infects us.

Approximately 90% of the human population is infected with either HSV1 or HSV2, in most cases without obvious symptoms. Nevertheless HSV1 has been implicated in Alzheimer’s disease, and infection with HSV2 increases the risk of contracting HIV, along with more immediate symptoms.

A/Prof Cheryl Jones of the University of Sydney’s Medical School says she and her colleagues have demonstrated that both strains of HSV infect Langerhans cells in the skin. “These are important immune cells, and we always thought they must have a role,” says Jones.