Australasian Science: Australia's authority on science since 1938

Feature

Feature article

Fruit Extracts Help Exercise Recovery and Asthma

By Roger Hurst

Natural fruit compounds may balance the impacts that exercise can have on the body and help breathing in some types of asthma.

It has long been accepted that fruit, vegetables and grains are good for us, but it is only more recently that scientists have begun investigating plant bioactive compounds and the mechanisms by which they keep us healthy.

Dr Roger Hurst leads the Food and Wellness Group at Plant & Food Research in New Zealand.

The Double-Edged Sword of Technology

By Graham M. Turner

When questions of population growth and sustainability are debated, the silver bullet of technological progress is usually proposed or implied. But historical evidence and simulations of the future demonstrate the danger of relying on technology.

The debate about population and sustainability has typically been fraught with rather simplistic and at times conflicting arguments. Many focus on population alone. Others focus on the potential for technology to deliver sustainability. Some touch on our materialistic consumerism.

Graham Turner is a senior analyst with the National Futures Group at CSIRO Sustainable Ecosystems.

Lie to Me

cartoon

Image: Simon Kneebone

By Michael Cook

Will brain scans revolutionise our legal system?

On 12 June 2008, 24-year-old Aditi Sharma became the first person to be convicted of murder based on a brain scan. The prosecution alleged that the MBA student had organised a tryst with her former fiancé at a McDonald’s in the Indian city of Pune. There she had given him sweets laced with arsenic.

Michael Cook is editor of the bioethics newsletter BioEdge.

Fire, Erosion and the End of the Megafauna

The distribution of dated erosion events in Tasmania

The distribution of dated erosion events in Tasmania over the past 105,000 years in relation to human arrival and the extinction of the megafauna. Note the increase in the number of erosion events after 40,000 years ago and the absence of a peak in erosion events in the cold period around 65,000 years ago. The image of the giant marsupial Zygomaturus trilobus is by Nobu Tamura.

By Peter McIntosh

Tasmania’s erosion history links ancient Aboriginal burning practices with the demise of Tasmania’s megafauna.

People have occupied the Australian mainland for at least 56,000 years, but Tasmania was the last part of Australia to be colonised – the oldest dated habitation layers in the state accumulated about 40,000 years ago.

Peter McIntosh is Senior Scientist (Earth Sciences) with the Forest Practices Authority in Tasmania.

A New Reason to Lose Sleep

Could the brain be more vulnerable to apnoea if CPAP therapy is discontinued?

Could the brain be more vulnerable to apnoea if CPAP therapy is discontinued? iStockphoto

By Caroline Rae

Are people with sleep apnoea prone to brain injury from oxygen deprivation?

Every night, people get into bed and go to sleep. But for some people what should be a restful and restorative time between the sheets can turn into a repetitive fight to breathe.

During sleep, the muscles in the upper airway relax, narrowing the airway. In obstructive sleep apnoea the airway relaxes too much, becoming closed and preventing the person from breathing. Hence the term obstructive sleep apnoea, meaning that the airway is obstructed, the person is asleep and is “without breath” (from the Greek “apnoea”).

Caroline Rae is Professor of Brain Sciences at The University of New South Wales and is based at Neuroscience Research Australia. This work was also conducted in collaboration with the Woolcock Institute of Medical Research.

Desert Fireballs

An Operational Desert Fireball Network camera station

An Operational Desert Fireball Network camera station on the Nullarbor, with satellite link and solar panel power source. Photo courtesy Geoff Deacon

By Alex Bevan, Philip Bland & Pavel Spurný

An intelligent camera system has been set up to track and recover meteorites in the Nullarbor.

The stuff from which many meteorites are made is 4560 million years old, and has remained virtually unaltered since its formation. Mainly representing debris left over after the planets were constructed, meteorites carry a unique record of the earliest events during the birth of the Solar System.

Meteorites can be fragments of rock, metal and mixtures of rock and metal mostly broken from asteroids in solar orbits between Mars and Jupiter. These broad groupings, however, belie the diversity of rocks that fall to Earth and are recovered.

Alex Bevan is Head of Earth & Planetary Sciences at the Western Australian Museum. Phil Bland is a Principal Research Fellow in the Department of Earth Science and Engineering at Imperial College London. Pavel Spurný is Head of the Department of Interplanetary Matter at the Astronomical Institute of the Academy of Sciences in the Czech Republic.

Life On Mars?

By Morris Jones

New NASA claims of Martian life in a meteorite discovered in Antarctica haven’t convinced astrobiologists.

We’ve looked across space through telescopes, thrown dozens of space missions at the planet and studied chunks of Mars that have fallen to Earth. Still, we don’t know for sure if there is life on Mars, but that hasn’t prevented vigorous and sometimes caustic debate for decades.

Dr Morris Jones is an Australian space analyst and writer.

Climate Change or Natural Variability?

Image of barometer

The long-term trend in annual rainfall for Australia from 1900 to 2009 is upwards at a linear rate of 6.33 mm/decade.

By Robert E. White

Meteorological records since the 1950s reveal a decrease in rainfall that is consistent with anthropogenic climate change, but a different picture emerges when looking at records since 1900.

The Fourth Assessment Report of the Intergovernmental Panel on Climate Change concluded that the increase in the Earth’s surface temperature during the second half of the 20th century can only be simulated by models that include anthropogenic forcing, and not just natural factors. However, the report acknowledges that there are difficulties in simulating and attributing observed temperature changes at smaller than continental scales, expecially when attempting to model the amount and distribution of rainfall.

Robert E. White is Professor Emeritus of The University of Melbourne’s School of Land and Environment.

Evidence for Indigenous Australian Agriculture

Aboriginal village near the NSW/SA border in the 1840s.

An Aboriginal village near the NSW/SA border in the 1840s.

By Rupert Gerritsen

The assumption that indigenous Australians did not develop agriculture is highly contestable, with a body of evidence revealing that they developed food production systems and in some cases lived in large villages.

It is a commonly held view that indigenous Australians in traditional circumstances never engaged in food production, specifically in terms of developing or adopting agriculture. Based on this assumption there has been extended debate on the supposed reasons for this (AS, March 2010, pp.19–21).

Such debates are meaningless if the initial premise is incorrect. And it may well be. Furthermore, if that assumption is incorrect it has significant implications for theories on the origins of agriculture.

Rupert Gerritsen is a Petherick Reader at the National Library of Australia, and author of Australia and the Origins of Agriculture.

The Young Visionaries

Image of child wearing cataract goggles

Truen Ibbotson experiences what it’s like to have restricted vision using special goggles designed by the Young Visionaries. Photo: Sharyn Wragg

By Mandy Thoo

Early-career scientists are using goggles that mimic common eye diseases to teach primary school children about their vision research and the importance of eye care.

In a school classroom in Canberra, a group of keen young scientists is giving primary school children a unique chance to literally see the world through the eyes of their grandparents and experience firsthand what it feels like to be going blind.

Vision Day at Kaleen Primary School in Canberra is just one of a series of public outreach events run by a group of scientists who call themselves the Young Visionaries – all early-career doctoral and post-doc researchers in The ARC Centre of Excellence in Vision Science (The Vision Centre).

Mandy Thoo is a Masters student in science communication at the Australian National University.