After experiencing traumatic events such as being assaulted or being caught
in a natural disaster, many people feel afraid, helpless and highly anxious. But
most recover within two to three months, says Richard Bryant, a psychologist at
the University of New South Wales in Sydney.

Between 10 and 15 per cent, however, experience a more severe reaction known
as acute stress disorder, characterised by feeling emotionally drained and
withdrawn. Many of these people go on to develop post-traumatic stress disorder
(PTSD), where they suffer from nightmares and flashbacks for years.

Identifying those with acute stress disorder is important, according to
Bryant, because this group needs the most help. “You don’t need to intervene
with everyone because most of them will get better themselves,” he says. Bryant
is critical of the current convention of providing everyone with counselling
(This Week, 13 February, p 24).
“The practice is based more on folklore and
tradition than scientific data,” he says.

Bryant and his colleagues have developed a test which they say can identify
those most at risk of developing PTSD. The researchers use an acute stress
disorder scale, based on 19 questions relating to the trauma. The questions
assess the incidence of bad dreams, level of concentration, and attempts to
avoid reminders of the event. Responses are scored on a scale of 1 to 5.

The researchers gave the questionnaire to 107 survivors of bushfires in
Hobart and Sydney twice in the month after the disaster. The survivors were also
assessed for PTSD six months later. The test managed to identify 91 per cent of
those who developed PTSD and 93 per cent of those that did not, the researchers
told the Pacific Science Congress in Sydney earlier this month.

Bryant describes the results as promising. “We are certainly finding those at
risk,” he says. But Bryant also admits the test will have to be refined and
combined with individual clinical assessment of victims. Although a test score
of 56 or more predicted most of those who went on to develop PTSD, about a third
of those who scored above the cutoff did not develop the condition. “We need to
weed out the false positives,” says Bryant.

“It’s a good way of identifying high risk groups,” says Martin Deahl, a
psychiatrist at St Bartholomew’s and Homerton Hospitals in London. Given the
resources that would be needed to effectively counsel everyone involved in a
disaster, such as the emergency services, targeting those most at risk is
useful. “But it mustn’t lead to complacency,” he warns.

Once finished, the dam will create a reservoir 600 kilometres long. At least
1.4 million people will have to move to new homes to escape the flood.

George Davis, an expert on parasitic diseases at the Academy of Natural
Sciences of Philadelphia, fears that the dam will cause an upsurge in
schistosomiasis—a disease caused by tiny blood flukes that in severe cases
leads to fatal damage to the liver and intestines.

Over the past five years, the infection rate has dropped by 50 per cent in
China, largely as a result of treatment with the drug praziquantel. But Davis
believes the disease could flare up again on the Yangtze. A smoothing out in the
cycle of flooding below the dam may cause numbers of the water snails that
spread the flukes to escalate, he says.

There may also be a problem if different snail populations can mix. At
present, infected snails are found 500 kilometres above the Three Gorges Dam
site and 40 kilometres below. These populations don’t mix, says Davis, because
snails above the site can’t survive the journey through the fast-flowing current
in the narrow gorges. But the dam will make this passage possible.

Although the snails come from different subspecies, they are likely to
interbreed—with unpredictable consequences for their ability to spread
disease to people. “When you mix genotypes, that’s how emerging diseases start,”
says Davis.

Adrian Sleigh, an epidemiologist at the Australian Centre for International
and Tropical Health and Nutrition at the University of Queensland in Brisbane,
is worried that poor standards of sanitation among the displaced people could
encourage other diseases. “Hundreds of thousands of people are going to be doing
little more than camping,” he says. Hanta-viruses, which are spread by rodents,
could pose a particular hazard, he argues.

Sleigh also says that the ambient temperature above the lake is likely to be
up to 1 °C warmer than above the water currently flowing through the gorges.
This could allow mosquitoes carrying Japanese B encephalitis and malaria to
proliferate.

However, Zheng Feng of the Institute of Parasitic Diseases in Shanghai told
the congress that the dam is needed for flood control and hydroelectricity. “The
gains and losses were carefully weighed,” he says.

Included among the finds is a giant flightless pigeon which stood 80
centimetres tall and looked like a dodo. Other discoveries include an iguana
about 1.5 metres in length, a giant frog measuring 25 centimetres, a giant
tortoise and a land crocodile 2 metres long.

Project head Atholl Anderson of the Australian National University in
Canberra says that the discoveries solve a long-standing puzzle, as similarly
large extinct beasts have been found in New Caledonia and Tonga, on either side
of the Fijian archipelago. “It’s always been suspected that there would be
megafauna on Fiji,” he says.

Because many of the bones are in fragments, Anderson suspects that the
crocodiles dragged them into the caves to eat. Radiocarbon dating of charcoal in
the caves suggests that the fossils are between 20 000 and 25 000 years old.
Anderson believes that some of the animals, including the crocodile and the
tortoise, disappeared from Fiji about 10 000 years ago when a rise in sea level
at the end of the last ice age reduced the Fijian land mass by two-thirds. But
the iguana, the frog and the flightless birds may not have become extinct until
after people arrived 2800 years ago.

The trouble with just looking at the present, says Archer, is that some
species have always had relatively small populations that fluctuate in size.
Species that seem more abundant can be in more serious trouble if they are
suffering from a protracted decline. “We have a dreadfully short-term
perspective when making assessments about conservation status,” says Archer. “In
most cases in Australia that perspective is less than 200 years.”

Yet Australia is in an ideal position to show why more notice should be taken
of the fossil record, says Archer. Over the past century, about half the world’s
extinctions of mammals have occurred on the island continent. And by looking at
fossil discoveries made at Riversleigh in western Queensland, Archer has been
able to track the fate of species between 30 million and 10 million years
ago.

These studies suggest that the current alarm in Australia about saving the
koala is unwarranted. “Its diversity through time is much the same as now,” says
Archer. “There have never been more than two kinds of koala in one habitat. It
has lost some of its range recently, but if money is to go into conservation,
this is not the mammal that needs it the most.”

The platypus, on the other hand, seems to be in serious trouble. Many species
of platypus once lived across huge tracts of Australia, including central
regions and the far north. There is now just one, a far less robust animal than
many of its predecessors. And over the past 25 million years, its range has
collapsed progressively eastwards towards the coast.

Similarly, the orange horseshoe bat is generally regarded as holding its own
in the caves of northern Australia. But again, many related species existed over
a much wider area in the past. It, too, needs special protection, according to
Archer.

If the fossil record of the Tasmanian tiger or thylacine had been known early
enough, he adds, it might have been saved from extinction. It would then have
been clear that indiscriminate hunting late last century was likely to hasten
its long-term decline.

Corals are built by tiny animals called polyps, which are nourished by algae
called zooxanthellae. If the water becomes too warm, the zooxanthellae can
die—followed swiftly by the polyps, leaving coral bleached and barren.

Ove Hoegh-Guldberg, director of the Coral Reef Research Institute at the
University of Sydney, says that coral bleaching was first observed in 1979.
Since then, there have been six major episodes, with the worst affecting reefs
throughout the tropics last year.

In a project commissioned by the environmental group Greenpeace,
Hoegh-Guldberg has now produced regional reef bleaching forecasts for the next
century. He unveiled his predictions this week at the Pacific Science Congress
in Sydney, a gathering of researchers from 26 nations bordering the world’s
largest ocean.

From data on known bleaching events, Hoegh-Guldberg was able to determine the
temperature at which bleaching appears to be triggered in different parts of the
world. He then used climate models which predict the rise in the temperature of
the sea surface for various tropical regions to produce his bleaching
forecasts.

Although reefs can recover from occasional bleaching events, Hoegh-Guldberg
predicts that those in Southeast Asia and the Caribbean could be experiencing it
annually within a decade. They will be joined by reefs off Tahiti by 2030 and by
Australia’s Great Barrier Reef between 2020 and 2030, he claims. “Even if there
is an episode every two years rather than every year, the corals won’t be able
to recover,” says Hoegh-Guldberg.

The destruction could be delayed if aerosols of smog in the atmosphere have
the cooling effect that some climate models predict. But Hoegh-Guldberg argues
that this will give a maximum of 50 years’ grace. “Even if you accept the
aerosol effect, the end result is still going to be the same,” he says. “It will
just take a little longer.”

In the long term, Hoegh-Guldberg admits that some corals will be able to
adapt to life in warmer seas. But with many species being lost, he says, the
reefs’ ecology will be irrevocably altered. “It will be another example of
survival of the fittest,” he says.

Not everyone agrees with his stark predictions. Terry Hughes, a reef
ecologist at James Cook University in Townsville, points to the fossil record
which suggests that corals have been subjected to warming trends many times and
have survived. “The gloom and doom scenario is overstated,” he says.

The industry is openly defiant, describing the law as laughable. “We will not
be incorporating unworkable provisions such as mandatory filtering of overseas
content,” says Peter Coroneos, executive director of the Australian Internet
Industry Association. “No other nation has thought it desirable to take these
sorts of steps,” adds Kim Heitman of Electronic Frontiers Australia, which
campaigns against online censorship.

Late last month, the bill passed a crucial vote in the Senate when two
independent senators holding the balance of power sided with the government. The
legislation will now be introduced to the House of Representatives, where the
government has a majority. It is almost certain to pass with little amendment,
and will be implemented on 1 January.

Under the new law, anyone will be able to complain to the Australian
Broadcasting Authority (ABA) about illegal or offensive material online. If the
ABA agrees that the material is unacceptable, it can then ask Net providers to
prevent access to the material. If the material is on an Australian server, it
must be taken down; if the host computer is overseas, providers must take
“reasonable steps to prevent access if technically feasible”.

The precise definition of “reasonable steps” is likely to be hotly contested,
experts predict.

For every 5000 of these Aboriginal players, one will die each year from heart
problems either on the field or shortly after the game has finished, a new study
has concluded. “That’s roughly ten times higher than the incidence of sudden
cardiac death in sport in general across all ages,” says Mark Young of the
Australian Institute of Sport in Canberra, who led the study.

Australian Rules is played at the highest level in Victoria, South Australia,
New South Wales, Western Australia and Queensland. But leagues have also sprung
up in the Northern Territory. Here, the Aboriginal population is much larger
than in other parts of Australia, and teams are dominated by Aboriginal
players.

The game involves play which can transfer the ball more than 160 metres from
one end of the pitch to the other in a matter of seconds. Unlike association
football, the ball is caught and handled, and kicks regularly send the ball 50
metres or more through the air. “It’s both aerobic, requiring a high oxygen
intake, and requires a physical toughness you don’t get with soccer,” says
Young.

In the south of Australia, the game is played in winter when temperatures are
low. But in the tropical Northern Territory, temperatures regularly exceed 30
°C, with high humidity.

The dangers of playing in such conditions first emerged in the early 1990s,
when two Aboriginal footballers collapsed and died. Young and his colleagues
then set out to find out how many young Aboriginal sportsmen suffered sudden
cardiac death in the Northern Territory. They found that eight sportsmen died
this way between 1982 and 1996—six of them Australian Rules players (
Medical Journal of Australia, vol 170, p 425).

The rate of sudden cardiac deaths among Aboriginal players in the Northern
Territory is 40 times greater than for players in Victoria, where they are
overwhelmingly white. In part, this huge difference is because Australia’s
Aborigines are 5.5 times as likely to die suddenly of heart attacks as members
of its white population. But the extreme conditions in the Northern Territory
are the main factor, Young says.

In some cases, they may be increasing the danger by playing when they are
dehydrated: four of the eight dead sportsmen in Young’s study are thought to
have consumed alcohol the night before.

Young is calling for the Northern Territory’s Aboriginal players to be
screened for cardiovascular problems and educated about risk factors such as
smoking and excessive drinking. He also wants games to take place at night when
it is cooler. However, few of the Aboriginal teams can afford the ÂŁ40 000
or more needed to install floodlights.

PlayTrac has been developed by Pineapplehead, a software company in Melbourne
which has been working with researchers at the Royal Melbourne Institute of
Technology. Players wear a radio transmitter-receiver called a transponder. The
prototype is a flat rectangle about 6 centimetres by 4 centimetres. The team
hopes to shrink this to a disc about 3 centimetres across that can be sewn into
sportswear.

The transponder, powered by watch batteries, has an antenna which sends
signals to three receivers around the playing field. During training,
physiological information, such as heart rate, is relayed to medical staff from
two electrodes strapped to the player’s body. “Each coach will know the
anaerobic threshold of individual players,” says Lamb. “They will know how much
running they can handle based on match day conditions.”

And by knowing the position of the receivers, it will be possible to analyse
players’ movements, based on the precise timing of the arrival of the signal at
each receiver. If all players on a field wear a transponder, coaching staff will
be able to decide tactics during a game with the aid of laptop computers. Data
are updated four times a second, and the system is accurate to within half a
metre.

Pineapplehead is still filing patents, so will not reveal the frequencies of
the signals used by its system. However, they avoid the microwave band favoured
by mobile phone manufacturers.

Hume Field of the Queensland Department of Primary Industry’s Animal Research
Institute in Brisbane is testing more than 300 blood samples taken from bats
throughout Malaysia
(This Week, 24 April, p 12).
In some populations, up to 25
per cent of them seem to have been exposed to the virus.

So far, however, the virus itself has not been isolated from bats, a crucial
step necessary to confirm that the animals are the reservoir. But virologists at
the US Centers for Disease Control and Prevention in Atlanta are now searching
for it in bat tissue samples.

A relative of the Nipah virus called Hendra was first isolated in Queensland
in 1994 and killed two Australians who had contact with infected horses. Bats
also appear to be the reservoir for the Hendra virus, and after this outbreak
Australian virologists applied for funding to check for the virus in bats
throughout Southeast Asia. That proposal was rejected, but following the Nipah
outbreak in Malaysia, Peter Young of the Queensland Animal Research Institute
hopes funding will be granted for work to start in July. “We want to check bats
from the Philippines, Indonesia, Malaysia and Papua New Guinea,” he says.

Meanwhile, John Mackenzie, a virologist at the University of Queensland in
Brisbane, plans to test the Malaysian blood samples collected by Field for
Ebola. Some scientists suspect that bats may also be the reservoir for this
virus.

Geologists have long been puzzled by the presence in the sands along
Australia’s east coast of minerals including zirconium silicate, or zircon,
which can’t be found in local rocks. But Keith Sircombe of the Australian
National University in Canberra believes he has solved the mystery after
analysing zircon samples from 10 beaches between Bundaberg in southern
Queensland and Mallacoota in eastern Victoria.

Sircombe measured the proportion of uranium to lead in each sample. Because
uranium decays into lead at a known rate, Sircombe was able to show that the
zircon deposits are almost all about 600 million years old, far older than any
of the rocks in eastern Australia—but similar in age to Precambrian rocks
in Antarctica.

At the ScienceNOW! meeting in Melbourne last week, which highlighted the work
of leading young Australian researchers, Sircombe revealed that the key to the
mystery is a large deposit called the Hawkesbury sandstone in the Sydney basin,
which was laid down about 240 million years ago. The deposits of zircon found up
and down the coast were washed from this deposit by waves, he argues.

But how did the Hawkesbury sandstone form? Australia and Antarctica were then
joined as part of the supercontinent of Gondwanaland. Starting about 280 million
years ago, eastern Antarctica was lifted up in a similar process to the uplift
now taking place in the Himalayas. Sircombe says that a huge river flowed from
there to the Sydney basin, where it deposited minerals eroded from rocks in
Antarctica. “We see similar patterns today caused by the rivers of the
±áľ±łľ˛ą±ô˛ą˛â˛ą˛ő.”