Science News Digest 26th July 2010
This week in science news we learn how gibbons jump large distances, find out that Stonehenge is not alone, discover stars many times larger than our sun, find out about a new hope in the fight against AIDS...and finally, meet the 'Super Marmot'.
Ape acrobats.
Scientists at the University of Liverpool and University of Antwerp have been studying gibbons to find out how they are able to leap long distances. The research, on a group of untrained white-cheeked gibbons living in the Planckendael Wild Animal Park revealed that there are four distinct methods by which they can propel themselves over great distances.
In the wild they have been seen to jump distances of up to 10 metres. The studies used high speed cameras to record the ape’s body position, as well as a forceplate to record the power exerted through the gibbon’s feet as they leapt.
The first and second methods of take-off were categorised as orthograde (body upright) single or double footed jumps. These are used when the gibbon is sure of its path.
"The orthograde single and two-footed leaps are likely useful during feeding and crossing short distances between branches of the same tree," explained Anthony Channon, a PhD. student from the University of Liverpool.
The other two leaping methods are the orthograde squat jump, and the pronograde (body parallel to the ground) single footed jump. The squat jump is more energetic, but gives the gibbon extra time to assess its surroundings whilst in the air, and could be useful when the ape traverses unfamiliar territory. The pronograde jump is used to initiate a bout of swinging between trees and probably adds sufficient velocity to aid this movement.
The ability of the gibbon to traverse skilfully through the tree canopy allows them to avoid descending to the forest floor where they would be at risk from predators.
Full story at the BBC
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Rock and roll.
An international team of scientists and archaeologists have discovered evidence of a second henge, less than 900 metres away from Stonehenge, on Salisbury Plain. Amazingly, the find required no excavation.
The site represents a circular ditch, which likely enclosed a ring of wooden posts. The site is visible from Stonehenge. The new find is believed to be from a similar age to its famous counterpart, estimated to have been built 4,500 years ago.
The new henge appears to have been constructed in the same orientation as Stonehenge, and comprises of a segmented ditch with entrances at the north-east and south-west.
No evidence of the ditch is visible at ground level, and the team used ground-penetrating radar to reveal the site. The find comes only two weeks into the three-year Stonehenge Hidden Landscape project, which aims to map the area around Stonehenge.
"Stonehenge is one of the most studied monuments on Earth but this demonstrates that there is still much more to be found," says Professor Vince Gaffney from the University of Birmingham.
Full story at the Guardian
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Starlight, star bright.
The largest known star in the universe has been discovered by astronomers from the UK. The star, known as R136a1, has a mass of approximately 265 times our sun, exceeding the largest size thought possible. The mass of this star would have been even larger when it was born, approximately a million years ago.
The star has a surface temperature of around 40,000C, seven times hotter than the sun, and luminosity thousands of times brighter. It is currently the brightest know thing in the universe.
R136a1 is 165,000 light years away, and was visualised using the Very Large Telescope (VLT), in the Chilean Atacama desert.
"Owing to the rarity of these monsters I think it is unlikely that this new record will be broken any time soon," says Prof. Paul Crowther, an astrophysicist at Sheffield University, who lead the research.
The team used the VLT to study two clusters of young stars, known as NGC 3603 and RMC 136a (where R136a1 is located), each containing small numbers of massive stars. These stars have a relatively short lifespan, before exploding in supernovae. Our sun, on the other hand, leads a relatively quiet existence, and is expected to burn out, rather than explode, in several billion years.
Full story at the Guardian
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A new hope in HIV prevention.
The results of a three-year study conducted by the Centre for the Aids Programme of Research in South Africa (Caprisa) have been hailed as a breakthrough. A vaginal gel has been found to cut HIV infection rate by up to 50% in a trial involving nearly 900 South African women.
The gel, infused with the anti-retroviral drug Tenofovir was tested in double-blind trials of uninfected women between 18 and 40 years old in the rural KwaZulu-Natal province. HIV incidence was 50% lower after one year in women who received the gel, and 39% lower after 2.5 years. No serious side effects were reported.
The gel was found to be effective when used once in the 12 hours before sex, and once in the 12 hours after. In sub-Saharan Africa almost 60% of those with HIV are women. Many years of research have gone into developing preventative microbicide which can be controlled by women.
It will be a long time before a product is widely available, with the gel likely to undergo clinical trials in the near future. However, this marks the first time a product infused with an anti-retroviral drug has proved effective at HIV prevention.
Mr. Michel Sidibe, executive director of UNAids, described the gel as a "powerful option for the prevention revolution and help us break the trajectory of the Aids epidemic".
Full story at the Independent
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While the sun shines.
Climate change is leading to longer summers in the Colorado Rocky Mountains. These longer summers are leading to marmots, ground dwelling squirrel like creatures, to wake earlier from hibernation, giving them extra time to fatten up and reproduce, say scientists.
The average mass of adult female yellow-bellied marmots has increased 11% since the animals were first studied in 1962. Marmots are usually only active for 4 or 5 months a year utilising the warm summers to gain weight and reproduce, before spending the rest of the year hibernating.
"Since the summers have become longer, marmots have had more time to do these things and grow up before the upcoming winter, so they are more likely to succeed and survive,” says Dr. Arpat Ozgul of Imperial College London.
This research is shedding light on how the animal kingdom is adapting to global climate change. The population of marmots may be increasing, but recent work carried out in Scottish sheep, suggests that the population of certain species may be shrinking as a direct response to climate change.
Full story at the Telegraph.
Ape acrobats.
Scientists at the University of Liverpool and University of Antwerp have been studying gibbons to find out how they are able to leap long distances. The research, on a group of untrained white-cheeked gibbons living in the Planckendael Wild Animal Park revealed that there are four distinct methods by which they can propel themselves over great distances.
In the wild they have been seen to jump distances of up to 10 metres. The studies used high speed cameras to record the ape’s body position, as well as a forceplate to record the power exerted through the gibbon’s feet as they leapt.
The first and second methods of take-off were categorised as orthograde (body upright) single or double footed jumps. These are used when the gibbon is sure of its path.
"The orthograde single and two-footed leaps are likely useful during feeding and crossing short distances between branches of the same tree," explained Anthony Channon, a PhD. student from the University of Liverpool.
The other two leaping methods are the orthograde squat jump, and the pronograde (body parallel to the ground) single footed jump. The squat jump is more energetic, but gives the gibbon extra time to assess its surroundings whilst in the air, and could be useful when the ape traverses unfamiliar territory. The pronograde jump is used to initiate a bout of swinging between trees and probably adds sufficient velocity to aid this movement.
The ability of the gibbon to traverse skilfully through the tree canopy allows them to avoid descending to the forest floor where they would be at risk from predators.
Full story at the BBC
-----------------
Rock and roll.
An international team of scientists and archaeologists have discovered evidence of a second henge, less than 900 metres away from Stonehenge, on Salisbury Plain. Amazingly, the find required no excavation.
The site represents a circular ditch, which likely enclosed a ring of wooden posts. The site is visible from Stonehenge. The new find is believed to be from a similar age to its famous counterpart, estimated to have been built 4,500 years ago.
The new henge appears to have been constructed in the same orientation as Stonehenge, and comprises of a segmented ditch with entrances at the north-east and south-west.
No evidence of the ditch is visible at ground level, and the team used ground-penetrating radar to reveal the site. The find comes only two weeks into the three-year Stonehenge Hidden Landscape project, which aims to map the area around Stonehenge.
"Stonehenge is one of the most studied monuments on Earth but this demonstrates that there is still much more to be found," says Professor Vince Gaffney from the University of Birmingham.
Full story at the Guardian
-----------------
Starlight, star bright.
The largest known star in the universe has been discovered by astronomers from the UK. The star, known as R136a1, has a mass of approximately 265 times our sun, exceeding the largest size thought possible. The mass of this star would have been even larger when it was born, approximately a million years ago.
The star has a surface temperature of around 40,000C, seven times hotter than the sun, and luminosity thousands of times brighter. It is currently the brightest know thing in the universe.
R136a1 is 165,000 light years away, and was visualised using the Very Large Telescope (VLT), in the Chilean Atacama desert.
"Owing to the rarity of these monsters I think it is unlikely that this new record will be broken any time soon," says Prof. Paul Crowther, an astrophysicist at Sheffield University, who lead the research.
The team used the VLT to study two clusters of young stars, known as NGC 3603 and RMC 136a (where R136a1 is located), each containing small numbers of massive stars. These stars have a relatively short lifespan, before exploding in supernovae. Our sun, on the other hand, leads a relatively quiet existence, and is expected to burn out, rather than explode, in several billion years.
Full story at the Guardian
-----------------
A new hope in HIV prevention.
The results of a three-year study conducted by the Centre for the Aids Programme of Research in South Africa (Caprisa) have been hailed as a breakthrough. A vaginal gel has been found to cut HIV infection rate by up to 50% in a trial involving nearly 900 South African women.
The gel, infused with the anti-retroviral drug Tenofovir was tested in double-blind trials of uninfected women between 18 and 40 years old in the rural KwaZulu-Natal province. HIV incidence was 50% lower after one year in women who received the gel, and 39% lower after 2.5 years. No serious side effects were reported.
The gel was found to be effective when used once in the 12 hours before sex, and once in the 12 hours after. In sub-Saharan Africa almost 60% of those with HIV are women. Many years of research have gone into developing preventative microbicide which can be controlled by women.
It will be a long time before a product is widely available, with the gel likely to undergo clinical trials in the near future. However, this marks the first time a product infused with an anti-retroviral drug has proved effective at HIV prevention.
Mr. Michel Sidibe, executive director of UNAids, described the gel as a "powerful option for the prevention revolution and help us break the trajectory of the Aids epidemic".
Full story at the Independent
-----------------
While the sun shines.
Climate change is leading to longer summers in the Colorado Rocky Mountains. These longer summers are leading to marmots, ground dwelling squirrel like creatures, to wake earlier from hibernation, giving them extra time to fatten up and reproduce, say scientists.
The average mass of adult female yellow-bellied marmots has increased 11% since the animals were first studied in 1962. Marmots are usually only active for 4 or 5 months a year utilising the warm summers to gain weight and reproduce, before spending the rest of the year hibernating.
"Since the summers have become longer, marmots have had more time to do these things and grow up before the upcoming winter, so they are more likely to succeed and survive,” says Dr. Arpat Ozgul of Imperial College London.
This research is shedding light on how the animal kingdom is adapting to global climate change. The population of marmots may be increasing, but recent work carried out in Scottish sheep, suggests that the population of certain species may be shrinking as a direct response to climate change.
Full story at the Telegraph.
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