news – Australian Science

Entelognathus: The Fish with the First Modern Face

Lauren — Wed, 16 Oct 2013 00:06:10 +0000

Entelognathus primordialis via Flinders Indaily

Hundreds of millions of years ago, armoured fish dominated the oceans, lakes and rivers of the world. These now-extinct creatures belonged to a class called Placoderms, meaning ‘plate-skinned’ in Greek. They had armoured plates covering their head and thorax, and they were the first creatures to develop teeth, pelvic fins, and most importantly, jaws. Jaws enabled them to become predators, which is thought to be a significant step towards the development of complex creatures like humans.

But for years, there’s been debate over whether placoderms are the ancestors of modern jawed vertebrates, because placoderms have a simple jaw made of one single bone while modern vertebrates have jaws made out of a more complex set of bones. There seemed to be something missing in the transition—evolutionary scientists have long puzzled over what happened in between the placoderms dying out and modern jawed vertebrates springing up. Now, though, a new discovery has shown that placoderms are, in fact, the ancestors we’ve been looking for.

In the suburbs of Yunnan in south-west China, a team of scientists recently found an exquisitely preserved fossil of a 419-million-year-old armoured fish. They dubbed it Entelognathus, meaning ‘complete jaw’. Entelognathus primordialis was part of the placoderm family. Around 20 centimetres long, it had bony plates around its head and front, just like a placoderm, but its jaw and facial structure were nothing like the placoderms. Entelognathus boasted a jaw composed of a complex arrangement of smaller bones. It had the same distinctive three-bone system that is still found in chewing vertebrates today: the lower jaw bone (the dentary bone), the two upper jaw bones (for holding the front teeth), and the maxilla (for holding the canines and the teeth further back in the cheek).

Image via nature.com

Entelognathus provides evidence that placoderms were actually the ancestors of all 30,000 species of living fish fauna today. The discovery adds to the list of “missing links

Cite this article:
Fuge L (2013-10-16 00:06:10). Entelognathus: The Fish with the First Modern Face. Australian Science. Retrieved: May 07, 2024, from http://australianscience.com.au/biology/entelognathus-the-fish-with-the-first-modern-face/

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Maria Island joins international ocean monitoring network

Editorial Board — Wed, 17 Apr 2013 00:08:34 +0000

A key facility in an international observing network to detect increasing ocean acidification is monitoring carbon cycling in the Tasman Sea from a site near Maria Island.

The A$150,000 mooring with its suite of environmental sensors is one of three in Australia’s Integrated Marine Observing System (IMOS) that are included in the international network in which Australian scientists at CSIRO and the Australian Institute of Marine Science are playing a central role.

The mooring was built at CSIRO’s Hobart Marine Laboratories, and deployed late last year at Maria Island, bringing the number of IMOS instruments at the Maria Island site to four. The instruments are managed and operated by CSIRO and the data is available free to the public at CSIRO National Reference Stations and Regional Sensor Arrays orIntegrated Marine Observing System [external link].

Others are located on the western side of Kangaroo Island, South Australia, and on the central Great Barrier Reef near Townsville. Extending the IMOS observations into the Southern Ocean is the French Antarctic supply ship l’Astrolabe and the Australian ice breaker, Aurora Australis. The vessels provide a platform for at-sea monitoring during return voyages from October to March between Hobart and the Antarctic bases they visit.

The observations made by the new mooring will provide data to determine the ocean acidification change and will fill a key need in assessing how the marine ecosystems of our region might be impacted.

Leading the acidification research is Dr Bronte Tilbrook from CSIRO’s Wealth from Oceans Flagship, who said the uptake and storage of carbon dioxide by the ocean is causing changes in the seawater chemistry and increasing acidity levels of surface waters.

The potential for impacts from the tropics to the polar oceans is large, and the resilience of ecosystems to these changes is poorly known.

“Elevated levels of carbon dioxide in the atmosphere have made the oceans about 30 per cent more acidic in the past 200 years.

“The ocean takes up about 25 per cent of annual carbon dioxide emissions generated by human activity. The ocean uptake is a great benefit because it removes human-generated emissions, but it comes at the cost of increased acidification of ocean waters.”

“Australia contains many ecosystems that may be sensitive to ocean acidification, including the extensive coral reefs of Northern Australia and down to the polar regions.

“Predicted impacts range from a decline in the growth of shells and skeletons of important species including corals and some shellfish, to shifts in the structure and dynamics of ecosystems,” he said.

Dr Tilbrook said the Australasian region contains some of the world’s most extensive carbonate-based ecosystems, ranging from the coral reefs of the Great Barrier Reef and Indo-Pacific, to the earth’s largest cool-water carbonate platform along the southern Australian shelf.

The surface waters of the Southern Ocean are where some of the most profound shifts in carbonate chemistry will occur by mid-century, potentially influencing the survival of deep-sea coral communities and calcifying pelagic species.

The Maria Island and Great Barrier Reef sites are part of a growing international network of moorings, and are located to characterise changes down the east coast of Australia and the influence of the East Australian Current. The Kangaroo Island mooring monitors deeper waters that can seasonally upwell onto the South Australian continental shelf. The upwelled waters are expected to have higher carbon dioxide concentrations that could accelerate the exposure of ecosystems to acidification earlier than in other regions.

Sensors on the Maria Island mooring also measure temperature, salinity, oxygen, chlorophyll and turbidity, while water samples are taken each month for plankton and nutrients. Basic measurement samples have been collected at Maria Island by CSIRO technicians monthly since 1944, providing scientists with an enviable ocean monitoring record.

More information: Integrated Marine Observing System.

Source: http://www.csiro.au/en/Portals/Media/Maria-Island-joins-international-ocean-monitoring-network.aspx

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Combating the rise of the superbugs: The health and scientific challenges of antibiotic resistance

David Borradale — Thu, 14 Mar 2013 00:01:17 +0000

It’s hard to imagine the world prior to antibiotics, a world where even a deep laceration could frequently spell significant illness or even death due to infection. Thankfully, since the discovery of penicillin in 1929 by Alexander Fleming, we now have a range of potent antibiotics to treat many of the various types of bacterial infection.

There is a problem though, bacteria are great survivors and have been competing against other bacteria and microorganisms for billions of years. As Professor Matt Cooper from the University of Queensland puts it “Billions of years ago, bacterial species were engaged in an arms race against each other and the chemicals they developed to kill one another have been modified into today’s antibiotics”.¹

Multi-Drug resistant Tuberculosis is a particular concern for health authorities and clinicians due to limited treatment options.

Unfortunately it’s our overuse of these important drugs which has driven the rapid development of antibiotic resistance, the process whereby bacteria containing mutations in their DNA, that provide some protection from an antibiotic, have an enormous survival advantage when exposed to the antibiotic and pretty soon dominate. Frequent exposures to the antibiotic may further strengthen these survival traits via the selection process, rendering the the drug less effective over time. It’s a great example of random variations leading to non-random adaptions through natural selection, although one with profound consequences for human health.

Of particular concern are bacteria that have developed resistance to multiple types of antibiotics, resulting in particularly dangerous resistant bacteria such as the multi-drug resistant variants of tuberculosis, that are extremely difficult to treat. Indeed leading health authorities are so worried about the problem that the Chief Medical Officer of the UK, Professor Dame Sally Davies, has recently labelled the threat as “catastrophic

Cite this article:
Borradale D (2013-03-14 00:01:17). Combating the rise of the superbugs: The health and scientific challenges of antibiotic resistance. Australian Science. Retrieved: May 07, 2024, from http://australianscience.com.au/biology/combating-the-rise-of-the-superbugs-the-health-and-scientific-challenges-of-antibiotic-resistance/

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New leader of CSIRO Astronomy and Space Science division

Editorial Board — Fri, 01 Feb 2013 00:03:22 +0000

CSIRO’s astronomy, spacecraft tracking and space science activities will be headed up by a new leader, with the announcement today that Dr Lewis Ball has been appointed as the incoming Chief for CSIRO’s Astronomy and Space Science (CASS) division.

Dr Ball returns to CSIRO from his present role as Deputy Director at the Atacama Large Millimeter/sub-millimeter Array (ALMA) located in Chile. There he has led the successful commencement of ALMA’s scientific operation, currently the world’s largest and most complex astronomical observatory and a partnership involving 20 countries.

“I look forward to enhancing and building on CSIRO’s national and international reputation in the fields of radio astronomy and space science. I’m excited and honoured to be leading such a world-class team and thrilled to be a part of the international SKA effort.”

Previous to his ALMA appointment, Dr Ball had been with CSIRO for nine years in a number of management roles including leadership of CSIRO’s astronomy division from February 2009 to May 2010, first as Acting Director of the Australia Telescope National Facility (ATNF) and then as Acting Chief of Astronomy and Space Science.

As the new CASS Chief, Dr Ball will lead approximately 280 staff and be responsible for a world-class national research facility for radio astronomy that includes three existing radio telescopes, as well as the 36-dish Australian Square Kilometre Array Pathfinder which begins operations this year. Dr Ball will also be responsible for driving CSIRO’s contribution to the first phase of the Square Kilometre Array telescope in Australia and for heading up, on behalf of NASA, the Canberra Deep Space Communications Complex based at Tidbinbilla.

Dr Ball’s appointment fills the role made vacant by Dr Phil Diamond, who left CSIRO in October 2012 to take up the position of Director General of the SKA Organisation.

Group Executive for CSIRO’s Information Sciences, Dr David Williams, welcomed Dr Ball’s appointment.

“Following an international recruitment search, we are delighted to see Lewis returning to CSIRO. Lewis has had enormous success in his career so far and we’re thrilled to have someone of such high calibre joining our leadership team,” Dr Williams said.

Dr Ball added, “I look forward to enhancing and building on CSIRO’s national and international reputation in the fields of radio astronomy and space science. I’m excited and honoured to be leading such a world-class team and thrilled to be a part of the international SKA effort.”

Dr Ball will commence as Chief of CSIRO’s Astronomy and Space Science division on March 18, 2013 and will be based at Marsfield in Sydney.

Source.

Image: Dr Lewis Ball has been appointed as the incoming Chief for CSIRO’s Astronomy and Space Science (CASS) division. Photo credit: ALMA(ESO/NAOJ/NRAO), M. Alexander (ESO)

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Telescope takes temperature of Universe

Editorial Board — Thu, 24 Jan 2013 00:02:31 +0000

CSIRO telescope takes temperature of Universe Astronomers using a CSIRO radio telescope have taken the Universe’s temperature, and have found that it has cooled down just the way the Big Bang theory predicts.

Using the CSIRO Australia Telescope Compact Array near Narrabri, NSW, an international team from Sweden, France, Germany and Australia has measured how warm the Universe was when it was half its current age.

“This is the most precise measurement ever made of how the Universe has cooled down during its 13.77 billion year history,” said Dr Robert Braun, Chief Scientist at CSIRO Astronomy and Space Science.

“This is the most precise measurement ever made of how the Universe has cooled down during its 13.77 billion year history.”

Dr Robert Braun, Chief Scientist, CSIRO Astronomy and Space Science

Because light takes time to travel, when we look out into space we see the Universe as it was in the past — as it was when light left the galaxies we are looking at. So to look back half-way into the Universe’s history, we need to look half-way across the Universe.

How can we measure a temperature at such a great distance?

The astronomers studied gas in an unnamed galaxy 7.2 billion light-years away [a redshift of 0.89].

The only thing keeping this gas warm is the cosmic background radiation — the glow left over from the Big Bang.

By chance, there is another powerful galaxy, a quasar (called PKS 1830-211), lying behind the unnamed galaxy.

Radio waves from this quasar come through the gas of the foreground galaxy. As they do so, the gas molecules absorb some of the energy of the radio waves. This leaves a distinctive “fingerprint” on the radio waves.

From this “fingerprint” the astronomers calculated the gas’s temperature. They found it to be 5.08 Kelvin (-267.92 degrees Celsius): extremely cold, but still warmer than today’s Universe, which is at 2.73 Kelvin (-270.27 degrees Celsius).

According to the Big Bang theory, the temperature of the cosmic background radiation drops smoothly as the Universe expands. “That’s just what we see in our measurements. The Universe of a few billion years ago was a few degrees warmer than it is now, exactly as the Big Bang Theory predicts,” said research team leader Dr Sebastien Muller of Onsala Space Observatory at Chalmers University of Technology in Sweden.

Publication “A precise and accurate determination of the cosmic microwave background temperature at z=0.89”, by S. Muller et al. Accepted for publication in the journal Astronomy & Astrophysics; online at

http://arxiv.org/abs/1212.5456

Source: News@CSIRO blog

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The Risk of Human Space Flight to Mars

Sharon — Wed, 19 Dec 2012 00:12:22 +0000

This past week NASA announced that in 2015 they would be sending two astronauts to the International Space Station (ISS) for a year-long mission. This is an expected, and necessary step in the preparation for human spaceflight to Mars. If we are to have human explorers on the surface of Mars, we need to understand the effects on humans of long-term space travel. At the moment trips to the ISS last on average 5-6 months. A mission to Mars may take 6-8 months, plus an extended time on the planet, and a 6-8 month return trip. In reality astronauts could be sent on missions of 2 years or longer.

The ISS as it orbits Earth. Photo credit NASA.

Astronauts are exposed to a number of conditions in space that can pose serious health risks, especially if exposure takes place over a long period of time. There are lots of hazards and risks for humans in space, including: ascent and descent accidents; space sickness; debris collisions; micrometeorites; hazardous and toxic gas leaks on the spacecraft; EVA (Extra Vehicular Activity) accidents; sudden unexpected illness and the list goes on. Today I’m talking about the specific issues that affect astronauts during long distance flights. (By the way I use the term ‘astronaut’ as a general term, which includes astronauts from various nations, including cosmonauts from Russia, and teikonauts from China.)

Some of the major issues for astronauts during long duration space flights include:

Exposure to radiation – Astronauts live and work well above the protective atmosphere of earth, so they are subject to the full force of the sun’s radioactive output as well as high energy cosmic rays that originate outside of our solar system. Long distance missions do not have the benefit of Earth’s protective atmosphere and magnetic field. Material shielding is effective against low energy radiation, but may create damaging secondary radiation for higher energy particles. The ISS uses aluminium to protect the spacecraft and crew. As the thickness of the shielding material increases, the probability that the particle will survive with enough energy to damage human issue is decreased. Low levels of radiation generally do not pose a significant health risk to astronauts, however the effects of radiation are cumulative, so long term exposure increases the lifetime risk to astronauts. Crews of future long duration interplanetary missions will have to travel through the Van Allen radiation belts, and be exposed to more galactic cosmic rays, and as a result will be exposed to higher levels of radiation than those remaining in Earth’s orbit. Increased and prolonged exposure to radiation has serious health consequences for astronauts, including cancer, leukaemia, heart disease, and damage to the central nervous system.

Muscle atrophy – Our muscles, bones and organs have adapted to work in the environment we inhabit, which is exposed to the effects of gravity. When exposed to an environment where there is little or no gravity, our muscles, bones and organs begin to lose condition – becoming more problematic the longer the astronaut is in space. On Earth, our muscles are constantly working against gravity. In space there is no force of gravity for muscles to work against, so astronauts will lose muscle tone. Loss of muscle tone starts to occur shortly after launch, and continues whilst the astronaut is in a reduced-gravity environment. During longer missions, muscles may atrophy, and astronauts may experience uncontrolled muscle twitching, and a loss of fine motor control. The loss of muscle tone, strength and control can be mitigated with regular exercise during the mission.

Astronaut Robert Thirsk, asleep in his sleeping quarters in the ISS. Photo credit NASA.

Cardiovascular damage – When in space, the body no longer needs to maintain the powerful heart muscles needed on Earth, so heart tissue begins to shrink. In space, astronauts experience a redistribution of body fluids, which results in changes to cardiovascular physiology. The heart doesn’t have to work as hard pumping blood in a microgravity environment as it does on earth so crew members are encouraged to undertake aerobic exercise as part of their daily routine, in addition to exercises designed specifically to maintain as much muscle tone as possible. Whist exercise is beneficial, it appears that it cannot reverse the process, but can help slow it down.

Bone density – In microgravity, the lack of impacts in weight bearing exercise means that newly created bone tissue is not incorporated into bones as normal, so as bone tissue is created it is absorbed into the system, not used as it would be on Earth. This results in high calcium levels elsewhere in the body, which can lead to significant health issues. Studies have revealed a significant loss of calcium from weight bearing bones of astronauts. This is a concern for astronauts as it suggests a risk of renal stone formation on long duration missions. Density in such bones as the pelvis and legs decreases by approximately 1 to 2 percent a month on average, which presents concerns for astronauts during long haul missions. Unfortunately exercise does not seem to reduce the level of bone loss, but is beneficial for many other issues as discussed previously.

Sunita Williams exercising on the ISS. Photo credit NASA.

Hyperarousal – Don’t worry – it’s not what you think! Astronauts may experience hyperarousal, their reaction to a changed schedule, working under pressure, sleep deprivation, and the excitement of being in space. Hyperarousal can cause insomnia, disrupt the appetite, result in impaired concentration, cognitive dysfunction, and decreased co-ordination. Fatigue is often a side effect of hyperarousal, as is anorexia and sudden weight loss. Over time space agencies have developed strategies to deal with hyperarousal, including giving crews adequate rest time, control over some of their tasks, adequate leisure time, and regular contact with family and friends.

Sleep deprivation – The amount and quality of sleep experienced in space is poor for a number of reasons including: variable cycles of ‘day’ and ‘night’; poor illumination during daytime hours in the space craft; environment outside the windows at the ‘wrong’ time of day; hectic work schedule; noise of the spacecraft; altered diet; and the physical challenge of sleeping in space. Sleep deprivation may compromise the immune system, which whilst not a significant issue during short term missions, is a potentially debilitating condition during long-term missions. Sustained physical stress over a long term period may result in an immune system that is so compromised that the body is unable to fight serious infections. Precautions include wearing sleeping masks and earplugs, anchoring themselves down to sleep, maintaining a steady routine of work and sleep, and using shades and other devices to block out the windows.

Psychological Issues – Working away from friends and family, and working with people from other cultures presents a number of psychological and social challenges. The psychological welfare of a crew of astronauts is critical to the success of a space mission. Interpersonal relationships during a mission may be a significant source of psychological stress. Crews do many things in space to try to maintain a sense of ‘normalcy’ during long stays in space. When crews aren’t required to work, they are encouraged to undertake other activities, which include reading, listening to music, writing e-mails and letters to family and friends, and exercising. In 2007 American astronaut Sunita Williams ran the Boston Marathon on the treadmill in the ISS, completing the race in just over 4 hours. During low earth orbit missions crews receive periodic care packages from their family with CDs, DVDs, books, magazines, photos, and letters. In addition to the packages, the ISS also has library lockers that contain music, books, and videos.

Over the last 40 years humanity has overcome enormous social, technical and physical challenges to put humans into space. When Yuri Gagarin became the first human in space by orbiting the Earth for 108 minutes on the 12th of April 1961, very little was known about the space environment and how it would affect humans. Just over 40 years later we now have a permanent presence in space with the introduction of the ISS into low Earth orbit. We know a lot about the physiology and psychology of humans in space, and have made space a relatively comfortable existence for astronauts. The future of space exploration may include human missions to other planets within our solar system, such as Mars. Before any long-term exploration of Mars could be contemplated, further research is needed in a number of areas to ensure the safety, and longevity of all crew members during the mission and beyond.

Cite this article:
Harnett S (2012-12-19 00:12:22). The Risk of Human Space Flight to Mars. Australian Science. Retrieved: May 07, 2024, from http://australianscience.com.au/space/the-risk-of-human-spaceflight-to-mars/

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Bike Brisbane: Brisbane winners announcement

Editorial Board — Fri, 15 Jun 2012 09:30:53 +0000

On Thursday, the Lord Mayor announced the winners of the hack::Brisbane competition at a presentation in New Farm Park. The winners of the hack::Brisbane competition are:

·Matthew Purcell for *Bike Brisbane* in the Open category http://data.brisbane.qld.gov.au/index.php/showcase/bike-brisbane/

·Kelwyn Graham for *Brisbane Access Map* in the Access & Inclusion category http://data.brisbane.qld.gov.au/index.php/showcase/brisbane-access-map/

Congratulations to both of the winners and everyone who entered the competition. The quality of applications was very high and the judges were very impressed with the variety and standard of all the applications.

Footage of the presentation by the Lord Mayor to Kelwyn (Matthew is currently overseas) can be viewed here:

Source image.

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Australian team nominated for European Inventor Award

Editorial Board — Thu, 03 May 2012 09:55:36 +0000

Dr. Josef Theurer is nominated in the category Lifetime achievement for his railway track-laying machines

Dr. John O’Sullivan and team nominated by European Patent Office for paving the way for Wi-Fi. Australian scientists laid world standard in modern communication and licence out their invention all over the globe.

Battistelli: “The innovation led by Dr. O’Sullivan and team has impacted on our daily life to an extent that only few inventions have achieved before.

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