The idea comes from Andrew Parker, a zoologist at the Australian Museum in
Sydney. While visiting the Museum of the Earth in Warsaw, Poland, he noticed
some electron micrographs of a fly from the family Dolichopodidae, preserved in
amber during the Eocene epoch. On the surface of the ommatidia that make up the
fly’s compound eye, Parker noticed gratings consisting of a series of parallel
ridges 145 nanometres high and 240 nanometres apart.

Parker suspected that the fly’s eye structure could capture light arriving at
up to 72 degrees from the perpendicular. The distance between the ridges is
about half the wavelength of light, which greatly reduces the amount of light
that they reflect. Parker believes that the ridges were probably an adaptation
to allow the fly to see better at night.

Researchers at the University of Exeter, led by Roy Sambles, an expert in
photonics, have now confirmed Parker’s hunch by embossing the same pattern onto
a film of light-sensitive emulsion. They fired laser beams of different
wavelengths at the material from a variety of angles and measured how much light
was reflected. “It turned out we had a really good antireflector over a whole
range of angles,” says Parker.

Armed with these results, materials scientist Geoff Smith and his colleagues
at the University of Technology, Sydney, have calculated that the fly’s eye
pattern could boost the energy generated by a solar panel over the course of a
typical day by 10 per cent. “It does almost as well with the Sun way over near
the horizon as it does at midday,” says Smith.

This might eliminate the need for the expensive and cumbersome tracking
systems currently required to keep solar panels pointing at the Sun as it moves
across the sky.

Within the next few months, Patrick Campbell of the photovoltaics research
group at the University of New South Wales in Sydney will attempt to etch the
extinct fly’s eye pattern directly onto the glass of a solar panel.

ĐÓ°ÉÔ­´´s at the Fraunhofer Institute for Solar Energy in Freiburg, Germany,
have independently been working on films embossed with similar patterns and have
reported increases in the amount of energy they absorb of about 3 per cent.

The blood-brain barrier comprises the tightly packed layer of cells lining
blood vessels in the brain. This highly impermeable layer protects the adult
brain by excluding pathogens and large molecules such as proteins.

The fetal brain was thought to exist in a different, “immature” state that
allows proteins to swirl around during development. Unlike in adult brains, it
was thought that small molecules can pass through gaps between the cells.

Controversially, however, physiologist Norman Saunders of the University of
Tasmania claims that even in the fetus, very tight junctions limit traffic
between the blood and brain. His claims are based on a study of the brains of
marsupials called South American opossums, which are born in a very immature
state—equivalent to rat fetuses at 13 weeks’ gestation.

He observed how the small molecules of a tracer substance called
biotin-dextran passed through cells of blood vessels that feed the brain and not
through gaps between cells, as they would if there were no blood-brain
barrier.

Brain physiologist Joan Abbott of King’s College, London, comments: “If true,
the findings might help us to understand the nature of some congenital defects.”

A team led by John Harries of the Australian Nuclear Science and Technology
Organisation in Sydney looked at 317 active and abandoned mines across the
country. It found that 54 of them contained significant amounts of waste that
could lead to acid contamination. A further 62 mines with smaller amounts of
waste were also a cause for concern. The survey was funded by the Department of
Environment.

Opencast and underground mining often exposes large amounts of pyrite and
other sulphide minerals to the air, which accelerates their oxidation. Once
oxidised to sulphates, they will form an acid in water that can severely damage
plant and animal life if it leaks from a mine. “In some areas it is [already]
impossible for any aquatic life to live in rivers,” says Harries.

The usual method of dealing with such waste is simply to bury it under soil
and rocks, and grow vegetation on top. But according to team member Graham
Taylor of the CSIRO, the Australian national research organisation, that is not
a long-term solution. He warns that rainfall can easily wash the acid into the
environment, and that it can bring with it dissolved heavy metals.

The scientists found most of the problems at abandoned mines, including an
old uranium mine at Rum Jungle in the Northern Territory and a zinc, lead,
copper and gold mine at Captains Flat near Canberra. Taylor says that the risk
would be significantly reduced if waste were properly treated while mines were
still active. Rehabilitating abandoned sites costs at least A$100 000
(ÂŁ38 000) per hectare, whereas the cost at active mines is about a third
of that.

Canada deals with the problem of acid wastes by placing them at the bottom of
freshwater lakes, where they cannot be oxidised. That option is not available in
Australia, because there are few large bodies of freshwater and evaporation
exceeds precipitation.

A WHO project that aims to reduce excessive drinking, coordinated at the
University of Sydney, is now entering its final phase. Its target is not people
who are addicted to alcohol, but those who nevertheless drink enough to damage
their health.

The WHO team, led by John Saunders of the University of Sydney and Nick
Heather of the Northern Regional Alcohol and Drug Service in Newcastle upon Tyne
in Britain, met in Sydney last week. They want doctors’ consultations to
routinely include a brief questionnaire designed to discover how much and how
often their patients drink.

Those who are drinking more than the internationally recommended limits per
week of 21 units of alcohol for men and 14 for women would be given a
five-minute, structured chat about reducing their consumption. One alcohol unit
is roughly equivalent to a glass of wine. In many countries, up to 30 per cent
of men and 15 per cent of women are thought to exceed the WHO’s limits.

“We are trying to make this an everyday part of good medical practice,” says
Saunders. A 10-year follow-up study of problem drinkers given similar advice on
cutting down has shown a 30 per cent decrease in levels of excessive drinking,
he says.

The WHO team is now trying to win political backing for the scheme in
countries across North America, Europe and Australasia. But even if governments
back the plan, will doctors be keen to take on the extra work? “I think it
should be a mandatory part of routine general practice,” says David Dammery,
acting chair of the Victorian Faculty of the Royal Australian College of General
Practitioners.

However, Bill Reith, the honourary secretary of Britain’s Royal College of
General Practitioners, says that many doctors struggle to cope with their
existing workload. “There is an issue of time,” he says.

Coral bleaching, in which coral polyps spontaneously expel the symbiotic
algae that give them their colourful hues, is thought to be related to a rise of
only 1 °C above average summer sea surface temperatures. Extremely warm
waters and unprecedented coral bleaching were reported throughout the tropical
areas of the southern hemisphere during the first half of 1998. When the waters
cooled in the second half of the year, the corals had either recovered or died
off. Fifty countries have reported the phenomenon since 1997.

Bleaching appears to indicate extreme stress in coral colonies, probably
related not just to temperature but also to the cloudiness of the sea water and
its salinity. Predicting changes in these factors may help scientists find ways
to lessen the effects of bleaching. AIMS and NOAA will share satellite and
ground-based data every day. “Our region could prove to be one of the keys to
global understanding of this problem,” says William Skirving, a remote sensing
specialist at AIMS.