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The Cosmic Ties that Bind Us

The results of a computer simulation of a cold dark matter universe.

The results of a computer simulation of a cold dark matter universe. Ordinary matter, in the form of stars and gas, is held to the dark matter via gravity and flows along filaments towards the largest local mass. The alignment of satellite galaxies around the Milky Way and Andromeda galaxies is a direct consequence of the filamentary nature of the universe.

By Stefan Keller

Astronomers have found a filament of ancient stars and galaxies that joins us to neighbouring clusters of galaxies and beyond to the vast interconnected universe.

Globular clusters hold hundreds of thousands of stars in a compact ball hundreds of light years across. From their colours and brightness these stars tell us that they are old – the majority formed at the same time as the Milky Way some 13 billion years ago.

Some globular clusters, however, are younger by several billion years than the majority. Understanding the creation of such star clusters has proven a problem.

Stefan Keller is a Research Fellow at the Research School of Astronomy and Astrophysics of the Australian National University, where he is the Operational Scientist for the SkyMapper telescope.

A Matter of Life & Death

Platelets are produced in the bone marrow by cells called megakaryocytes.	iStock

Platelets are produced in the bone marrow by cells called megakaryocytes. iStockphoto

By Vanessa Solomon, Benjamin Kile & Emma Josefsson

Discovering the factors that control the lifespan of the cells that form blood clots could improve cancer treatments and extend the shelf-life of blood donations.

Mammals have evolved a blood-clotting system that stops bleeding by plugging damaged blood vessels. This blood-clotting system involves platelets and must be tightly regulated. Low platelet numbers in the blood or clotting factor deficiencies like haemophilia can cause fatal blood loss. Conversely, pathological platelet activation can lead to heart attack or stroke when clots block blood vessels in the heart or brain.

Vanessa Solomon, Benjamin Kile and Emma Josefsson are based at The Walter & Eliza Hall Institute of Medical Research.

The Thylacine Myth

Two Tasmanian tigers in Hobart Zoo prior to 1921. Photographer unknown.

Two Tasmanian tigers in Hobart Zoo prior to 1921. Photographer unknown.

By Marie Attard & Stephen Wroe

A new study of the biomechanics of the Tasmanian tiger’s skull debunks the hysteria behind the campaign that led to its extinction.

They were one of Australia’s great biological mysteries, a biscuit-coloured marsupial with a large head, bold dark stripes down its back and a reverse-facing pouch. To newly arrived European settlers, this elusive New World creature was a Tasmanian oddity that inevitably became a source of confusion, contempt and fear. Now, 75 years after the last known individual died in captivity at Hobart Zoo, the thylacine – or Tasmanian tiger – remains one of the least-understood of Australia’s native animals.

Marie Attard is a postgraduate student studying the diet of Tasmanian tigers at the University of NSW School of Biological, Earth and Environmental Sciences, where Stephen Wroe is a Senior Research Fellow and the director of the Computational Biomechanics Research Group.

The Lost Riches of the Himalaya

Aerial view of several Himalayan glaciers.

Aerial view of several Himalayan glaciers.

By Lloyd White

Most of the world’s gold and copper deposits are formed at tectonic plate boundaries. It’s a pity, then, that geologists find it difficult to locate the ancient plate boundaries in the Himalayan mountains.

The Earth’s surface is divided into a number of tectonic plates that are constantly moving. They grind against one another, tear apart and crash into each other, triggering earthquakes and volcanic eruptions. Over time this movement also results in the formation and destruction of vast oceans such as the Indian and the Pacific, and great mountain chains such as the Himalaya and the Andes.

Lloyd White is now a postdoctoral research fellow at the Australian National University’s Research School of Earth Sciences.

Shade & Light

Some reef fish require large table corals to conceal them.

James Cook University researchers James Kerry and Professor David Bellwood constructed artificial habitat to test the attraction of concealment for large reef fish.

By James Kerry

Climate change is reducing the complexity of coral reefs, with implications for the reef fish that require large table corals to conceal them from predators, prey, and even ultraviolet light.

Healthy coral reefs are architecturally complex environments sporting a diversity of structures that include corals, overhangs, grooves, tunnels and spurs. This structural complexity is one of the elements that makes coral reefs so visually appealing, but hidden within the reef complex there might be certain shapes that are particularly important for the survival of reef fish.

James Kerry is a PhD student in marine biology at James Cook University. The research was funded by the ARC Centre of Excellence and is published in the scientific journal Coral Reefs.

Can We Program Safe AI?

Credit: iStockphoto

Credit: iStockphoto

By Steve Omohundro

Tomorrow’s software will compute with meaning and be much more autonomous. But a thought experiment with a chess robot shows that we will also need to carefully include human values.

Technology is rapidly advancing. Moore’s law says that the number of transistors on a chip doubles every 2 years. Moore’s law has held since it was first proposed in 1965 and extended back to 1900 when older computing technologies are included.

Steve Omohundro is President of Self-Aware Systems.

The Future of GPS

Credit: iStockphoto

Credit: iStockphoto

By Drew Turney

With jammers now available for only $20, civilian and military use of GPS is no longer secure. Has the GPS had its day, or will a competing system soon take over?

“It’s an exquisite technology but it was designed in the time of record players and vacuum tubes, and the design brief to the engineers was to track intercontinental ballistic missiles. They never imagined a world with iPads and mobile phones.”

That’s how positioning system entrepreneur Nunzio Gambale describes the global positioning system (GPS). Like the Internet, the GPS has morphed into something quite different from its original purpose, an enabler for other tools and industries to piggyback and make life better for everyone.

Drew Turney is a freelance writer.

Frozen in Time: What Caused the Extinction of the Ice Age Megafauna?

© Yukon Government, Art by George "Rinaldino" Teichmann

The megafauna of Siberia and Alaska included muskoxen, bison, wild horses and woolly mammoths. © Yukon Government, Art by George "Rinaldino" Teichmann

By Simon Ho

A new study of ancient DNA preserved in permafrost has revealed that Ice Age megafauna varied considerably in their ability to survive climate change and the spread of humans.

Over the past 50,000 years the world has lost many of its large animals. Among the “megafauna” species that disappeared were iconic mammals like the woolly mammoth and woolly rhinoceros, which roamed the tundra during the last Ice Age. The intensity and timing of these megafauna extinctions varied among different regions of the world.

Simon Ho is a Senior Lecturer and an Australian Research Council Queen Elizabeth II Research Fellow in the School of Biological Sciences at the University of Sydney.

The Transit of Venus, 2012

Credit: Geoffrey Wyatt, Sydney Observatory/Powerhouse Museum

Geoffrey Wyatt’s prize-winning image of the 2004 transit was taken with a special filter that only allows through the red light of hydrogen atoms. Credit: Geoffrey Wyatt, Sydney Observatory/Powerhouse Museum

By Nick Lomb

Transits of Venus allowed astronomers to calculate the scale of the solar system, and led to the discovery of Australia. On 6 June this year Australians and New Zealanders will have a ring-side view of one of the most famous events in astronomy – and the last one for another 105 years.

Next month the planet Venus will pass in front of the Sun for the last time until the year 2117. This event is the rare and famous transit of Venus, which has only been seen six times in recorded history – the first sighting was in 1639 and the last in 2004.

Transits of Venus are of exceptional significance to Australians because the voyage of James Cook that led to the settlement of the country by the British was to observe the transit of June 1769 from Tahiti. To astronomers of the

Dr Nick Lomb spent 30 years as an astronomer at Sydney Observatory, which is part of the Powerhouse Museum, and is still closely associated with it. His book Transit Of Venus: 1631 to the Present is published by NewSouth and Powerhouse Publishing, and provides the full story of the transits of Venus (see http://www.sydneyobservatory.com.au/transit-of-venus-the-book/). Sydney Observatory will run programs associated with the transit of Venus on 6 June 2012, including safe solar viewing if sky conditions permit. For details, see http://www.sydneyobservatory.com.au/transit-of-venus-at-the-obs/

Of Mice & Men

iStockphoto

Image: iStockphoto

By Claire Thompson

Are mouse models of immune disorders of the human gut, such as inflammatory bowel disease, reliable? And can probiotic supplements keep us healthy?

The intestine is a place where man and microbe meet. From the moment we are born, bacteria colonise our intestines, entering via the food we eat and from contact with our environment.

Claire Thompson completed this research as a PhD student at the University of Sydney’s School of Molecular Bioscience. She is now a postdoctoral fellow at the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany.