Australasian Science: Australia's authority on science since 1938

Browse in Brief

By Stephen Luntz

Brief bites of science news for subscribers only.

RNA’s Role in Schizophrenia
An enormous global collaboration has published evidence in Nature Genetics for a role for non-coding DNA in schizophrenia.

More than 200 authors, including Australians associated with four universities, found five new areas of the human genome where variations are associated with schizophrenia. One of these is located away from any protein-encoding genes, but in a region associated with microRNA known as MIR137. MicroRNAs bind to messenger RNA to silence genes.

MIR137 is involved in the production of neurons in the adult brain, and sites affected by MIR137 have been associated with schizophrenia. It appears that while variations in the genes themselves can contribute to schizophrenia, unusual forms of MIR137 may also be important by influencing these genes’ expression.

Aussie Kids Are Early Internet Adopters
Australian children are accessing the internet earlier than their European counterparts, and may be the youngest internet starters in the world.

A survey, AU Kids Online, was conducted by the ARC Centre of Excellence for Creative Industries and Innovation in parallel with a 25-nation European study.

“This is the first Australian study of its kind where children were directly interviewed on a large scale about their online experience,” says Prof Lelia Green. “It gives us significant empirically sound information about the opportunities and the risks for Australian children in the online and mobile media era.”

On average Australian children started using the internet shortly before their eighth birthday, younger than any of their European counterparts. Within the 9–16-year-old sample, 76% went online daily for an average of more than 90 minutes.

While parental and teacher mediation was high, Green says that “30% of Australian children reported encountering something online that upset or bothered them – two-and-a-half times the European average. The content predominantly related to online bullying and sexual images, which were more likely to bother younger users.”

Komodo Dragon’s Pull Is Worse than Its Bite
Dr Stephen Wroe of the University of NSW continues to upend our ideas about the bite force applied by fearsome predators. Having shown that the bite of the sabre-tooth tiger was “a bit like a moggy” (AS, Nov/Dec 2007, p.7), he has now determined that if you are encountering a komodo dragon it is not its bite you need to fear.

“Measured bite force in Varanus komodoensis… is low for its body mass relative to other vertebrates,” Wroe wrote in a paper published in PLoS One. Unsurprisingly, larger komodo dragons do have a stronger bite, but it seems that its main hunting and “defleshing” tool is the movements of its neck and shoulders rather than the strength of its jaw.

Of course, now that Dr Bryan Fry has shown that the komodo dragon is venomous (AS, Jan/Feb 2006 p. 6), a strong bite really might be considered overkill.

Glaucoma a Risk Factor in Falls
Glaucoma is a major risk factor in falls among the elderly, Dr Alex Black of the Queensland University of Technology’s Faculty of Health has confirmed. Black says the results will assist in fall prevention.

“While it may sound like common sense that people with impaired vision would experience more falls than those with good vision, this was the first study that identified the particular type of glaucoma sufferer most at risk,” Black says. “Armed with this knowledge we can move onto educating patients so they can better understand the extent of their vision loss and its ramifications on their day-to-day living.”

Black found that the greatest risk factor is extensive damage to the lower peripheral vision. He recommends improved lighting, exercising in full daylight rather than at dusk, and “activities that maintain and promote balance and strength, such as Tai Chi.”

Stress Test Predicts Dementia
A mental equivalent of physical stress tests can be used to predict the risk or dementia.

Prof Michael Breakspear of the Queensland Institute of Medical Research said: “We studied Australians aged between 70 and 85 with mild cognitive impairment, which is a known risk factor for dementia. They were given a series of memory tasks of increasing difficulty and their brain activity was monitored – think of a heart stress test but, instead of running on a treadmill, we make you think to the point of mental exhaustion and measure your brain activity.”

Not only was the brain’s altered response as stress rose a good indication of cognitive decline 2 years later, but other measures failed. These included age, education level, brain volume and initial cognitive function.

“Ultimately we hope our research may lead to a clinical tool to identify those at risk. This would allow early intervention, better targeting of the available medications and hence improve the lives of those living with this terrible condition,” Breakspear said.

Yoghurt Keeps Arteries Thin
Consumption of 100 grams or more of yoghurt per day is associated with decreased thickening of the carotid artery in elderly women, researchers at Sir Charles Gardener Hospital in Perth have reported in the American Journal of Clinical Nutrition.

Carotid artery intima-media thickness (CCA-IMT) is a risk factor for cardiovascular disease.

“In general, dairy products get a bit of a bad rap in regards to cardiovascular disease, but there has been a demonstrated cardiovascular benefit in probiotic and yoghurt consumption,” said lead author Ms Kerry Ivey.

The team tested the effects of yoghurt, milk and cheese consumption on 1080 Perth women over the age of 70. They found no correlation between overall dairy consumption and CCA-IMT, but clear benefits from yoghurt.

“We’re trying to explore the benefits of yoghurt as distinct from their dairy characteristics,” Ivey said.

Clothing Made of Water
Showering, cleaning, flushing and even watering the garden account for just 6% of an average household’s total water consumption a University of Melbourne study has found.

“In order to produce any item, from a pair of jeans to a toaster, water is required to obtain raw materials, in the manufacturing process, in transportation and to sell the item,” said Dr Robert Crawford of the Faculty of Architecture, Business and Planning.

While many people are aware that lots of water goes to grow their food, Crawford found that clothing requires even more. Electricity production, other than wind or certain forms of solar, is also water-intensive.

Crawford noted: “Many people upgrade dishwashers and washing machines to save water. However, it is important to also think about the water involved with producing these items. Sometimes this water demand may outweigh the potential water savings.”

The report was published in Building Research and Information.

Transient Strokes Require Heeding
Every year thousands of Australians are hospitalised as a result of a transient ischaemic attack (TIA) in which the brain is temporarily starved of oxygen. The effects are similar to those of proper strokes, but are far more temporary.

TIAs have long been regarded as warning signs for real strokes, and Dr Melina Gattellari of the University of NSW School of Public Health and Community Medicine has demonstrated the importance of heeding this signal. Nine years after the event, Gattellari found that more than half of TIA patients admitted to hospitals in NSW had died, a mortality rate that is 20% higher than others of similar age.

Gattellari recommends “good blood pressure control, optimising management of diabetes and heart failure, giving up smoking, regular exercise, weight control and good management of other risk factors like atrial fibrillation”.

Unexpected Coral
Retired marine biologist Dr Barry Wilson has drawn on indigenous advice to locate coral reefs in waters that were considered too muddy for exploration by his peers.

Talbot Bay in the Kimberley is known for its enormous tides and turbid muddy waters. Turtle Reef, within the Bay, was considered an unlikely place for corals, which prefer clear oceanic waters. Yet the Bardi-Jawi people of One Arm Point suggested to Wilson that the location harbours coral. He found a rich reef system with many coral species, 70% of which are also found on the Great Barrier Reef.

“This is the sort of information which some people will find difficult to believe because they have all been taught that corals all need clear oceanic water ,and it’s not true,” says Wilson.

The discovery was published in the Journal of the Royal Society of Western Australia.

An Indicator of National Happiness
The red panda lacks the profile of its giant namesake, and little is known about its ecology. However, Sangay Dorjii, a wildlife conservation officer with the Bhutanese Department of Forests and Park Services, has started to address that in the course of a Masters degree at the University of New England.

As a charismatic but threatened species, the panda is a potential drawcard for Bhutan’s tourism industry, but Dorjii says: “Sixty-five per cent of Bhutan’s households in rural areas exploit potential red panda habitat to meet their needs, in conjunction with an equal urban-based demand for timber and firewood”.

Dorjii found that the pandas live in “cool broadleaf and conifer forests between 2110 and 4389 metres above sea level”. He suggests the panda could be used as an indicator species for the health of these forests, and might even help Bhutan track its goal of maximising its Gross National Happiness through the maintenance of its forests.