Australasian Science: Australia's authority on science since 1938

Briefs

By Stephen Luntz

How does masculinity drive eating disorders, are horses racing too young, and do stimulants make truckies safer drivers?

The Cost of Quad Bikes

Quad bike crashes cost Australia $288 million between 2001 and 2010, a study by the University of Sydney’s Centre for Agricultural Health and Safety has found, yet 70% could have easily been prevented.

“This conservative estimate draws on deaths data from the National Coroners Information System and includes projected losses in future earnings, impacts on household contributions, insurance payments, investigation and hospital costs,” said Dr Tony Lower. “These costs are only the tip of the iceberg as they don’t account for the pain and suffering incurred by families, friends and communities – nor the significant costs associated with life-threatening and permanently life-changing non-fatal injuries such as spinal and head injuries.”

The researchers estimated that 40% of deaths would have been prevented from the fitting of a crush protection device, while other actions such as the use of helmets would prevent another 30%.

The work was published in the Australian and New Zealand Journal of Public Health, and was accompanied by an editorial comparing bike manufacturers to the tobacco industry in their efforts to hide their own research on the dangers of their products.

Caffeine Saves Truck Drivers

The idea of truck drivers wired on stimulants to keep them awake might be frightening but it does work, according to Ms Lisa Sharwood of the George Institute, University of Sydney.

In a study of more than 1000 truck drivers published on bmj.com, Sharwood found that 43% took caffeine in coffee, tea or tablet form in order to stay awake at the wheel. After adjusting for age, kilometres driven, sleep patterns and schedules Sharwood found those who took caffeine to stay awake were 63% less likely to crash than those who did not.

Having had a previous crash within the previous 5 years increased the risk of a repeat by 81%, raising questions about the suitability of some drivers.

Caffeine “may seem effective in enhancing their alertness, but it should be considered carefully in the context of a safe and healthy fatigue management strategy; energy drinks and coffee certainly don’t replace the need for sleep,” Sharwood said.

Malaria Drug Potential

Monash and Griffith University scientists are involved in the development of the most promising new malaria drug for some time. A study in Science Translational Medicine has announced the success of ELQ-300 in clearing the malaria parasite from both the blood and the liver of mice.

Anti-malarial drugs are common, but the parasite has succeeded in evolving resistance rapidly to each new drug to such an extent that it is now standard to give two unrelated drugs in the hope of killing the parasite before resistance can appear.

However, a comparison of ELQ-300 and existing drug atovaquone found the new drug 30 times more effective and far less likely to produce resistance in culture.

Safety tests for human use are still required but Dr Karen White of the Centre for Drug Candidate Optimisation at Monash is part of a large international team claiming that if ELQ-300 proves safe it could have an unusually long lifespan as a malaria drug, and may even kill the parasite in mosquitoes that bite people who are taking it.

Soft Drink Consumption at Home

Being male and from a lower socio-economic background increases the risk of school-aged students drinking too much soft drink, a study published in Preventative Medicine has found. However, the greatest risk factor is living in a house where the drinks are available.

Ms Lana Hebden of the Sydney Medical School added: “We also found students who drank soft drink with meals at home were almost 10 times as likely to be high consumers of these drinks”.

Consumption from school canteens was also a significant factor. “While there is a mandate from 2007 that schools should not sell sugar-sweetened drinks, such as soft drinks, at school, this policy is not monitored or policed,” says Hebden.

Eating Disorders and Masculinity

Whether men relate to masculine or feminine stereotypes is more important than sexuality in driving eating disorders, a University of Sydney study has found.

In the Journal of Eating Disorders psychologists reported that men with muscle dysmorphia – sometimes known as “bigorexia” – are more likely to identify with masculine stereotypes than other gym users. Muscle dysmorphia involves the belief that the body is never muscly enough, no matter how much exercise is done. On the other hand, men who identify with stereotypically feminine traits are more likely to suffer from anorexia.

“This study, if replicated, may provide valuable information for researchers to develop better treatment programs for men with eating disorders,” said co-author Prof Touyz.

Study leader Dr Stuart Murray described the conditions as “an indication of the increasing pressures men are under to define their masculinity in the modern world”.

Early Starts Don’t Hurt Horses

Racing of 2-year-old horses has received criticism at Australia’s Senate Select Committee on Animal Welfare, but it doesn’t affect the length of a horse’s career, according to a paper in the Equine Veterinary Journal.

“This is the largest and most extensive study of its type as we investigated the careers of over 115,000 Australian thoroughbred racehorses and evaluated them throughout a 10-year period,” said Dr Natasha Hamilton of the University of Sydney’s Faculty of Veterinary Science.

Hamilton used the actual date of birth of the horse rather than its year and the point at which it first raced. “The survival analysis showed the risk of retirement from racing decreased the younger the horse was when it ran its first race,” she said. However, Hamilton added that it is important training regimes take into account any genetic predisposition to injury.

Fat Protects Bones

The global obesity epidemic has a positive side, possibly explaining why rates of bone fracture are falling.

The Dubbo Osteoporosis Epidemiological Study of 1126 people over the age of 50 found that the highest quarter of women by abdominal fat had a 40% lower risk of bone fracture than the rest of the population. No such trend was found in men, but this may have been related to sample size as less than half as many men as women participated in the study.

Dr Shuman Yan and Prof Tuan Nguyen of the Garvan Institute published the finding in the Journal of Clinical Endocrinology. They speculate that the differential effect by sex may because oestrogen levels, which are higher in women with more abdominal fat, protect against bone loss.

Laser Mapping Preserves Heritage

Mobile 3D laser mapping is being used to keep a record of cultural heritage sites. CSIRO’s Autonomous Systems Lab has developed a handheld laser scanner to map the surfaces of buildings to exceptional detail. They named it Zebedee after the spring-borne character from the children’s series The Magic Roundabout.

“Zebedee has allowed us to capture a detailed record of several key cultural heritage sites, ranging from those which are fragile and at risk of damage through natural disasters to those which are remote and difficult to get to,” said Prof John Macarthur, Dean and Head of the School of Architecture at The University of Queensland.

Besides preservation, it is hoped the mapping will allow detailed studies in future without hand measurement. A study of the Peel Island leper colony near Brisbane revealed how much smaller and more crowded the accommodation for indigenous inhabitants was compared with non-indigenous inmates.

Geckos to Go

Modelling suggests that arid zone reptiles may struggle to cope with the effects of climate change as they would not be able to shift with climatic zones. “The real question isn’t where they are going, but can individuals actually reach a suitable new home before it becomes critical to their survival,” said Macquarie University PhD student Paul Duckett.

Using the tree dtella (Gehyra variegata) as a case study, Duckett found: “While we were able to identify suitable habitats for these geckos, our model showed that almost half of the populations would fail to get to these areas in time.”

While some species would have escape locations at the tops of mountains, the tree dtella would be forced to travel south-east from central Australia, and projected habitat movements in response to rising concentrations of greenhouse gases would be too fast for the more remote gecko’s little legs.

Subtle Hearing Challenges

Hearing difficulties have a well-established impact on children’s capacity to learn, but new research suggests further testing may be required.

A/Prof Simon Carlile of the University of Sydney’s Auditory Neuroscience Laboratory studied children who had trouble switching their attention to follow a conversation between two or more other speakers. “A wide battery of clinical tests indicated that children who complained of listening difficulties had otherwise normal hearing sensitivity and auditory processing skills,” Carlile said.

Despite showing up as normal on existing tests, these children struggled to follow discussions with a number of participants, particularly in noisy environments, and were more likely to be doing poorly at school.

“What we have done is provide a tool to diagnose a particular symptom that indicates an underlying problem that has been undiagnosed to date,” Carlile said. Two-thirds of the students had not been diagnosed with a problem when brought to an audiology clinic.