Neuroscientists in America have found a way to stimulate memory with electrical current using magnetic pulses, with enormous potential to treat memory disorders resulting from stroke, Alzheimer's and brain injury.
The doctors at Northwestern University in Chicago also showed for the first time that remembering events requires many brain regions to work in concert with a key memory structure called the hippocampus – like a symphony orchestra with each instrument playing its part.
They say the electrical stimulation is like giving the brain regions a more talented conductor so they play in closer synchrony.
Joel Voss is assistant professor of medical social sciences at Northwestern University Feinberg School of Medicine and senior author of the paper published in Science today. He says It isn't possible to directly stimulate the hippocampus because it's too deep in the brain for the magnetic fields to penetrate.
So, using an MRI scan, Voss and colleagues identified a superficial brain region a centimeter from the surface of the skull with high connectivity to the hippocampus. He wanted to see if directing the stimulation to this spot would in turn stimulate the hippocampus. Voss says
We show for the first time that you can specifically change memory functions of the brain in adults without surgery or drugs, which have not proven effective. This noninvasive stimulation improves the ability to learn new things. It has tremendous potential for treating memory disorders."
Astronomers have finally settled a dispute over just how far the Pleiades star cluster – one of the most familiar sights in the night sky – are from Earth.
Until the 1990s the consensus was 430 light years, but then the European satellite Hipparcos, which was launched in 1989 to precisely measure the positions and distances of thousands of stars, came up with a distance of about 390 light-years.
You wouldn't've thought 40 light years was such a big deal given the immense distances involved, but Carl Melis, of the University of California, San Diego, say it was.
That may not seem like a huge difference, but, in order to fit the physical characteristics of the Pleiades stars, it challenged our general understanding of how stars form and evolve. To fit the Hipparcos distance measurement, some astronomers even suggested that some type of new and unknown physics had to be at work in such young stars.
The Pleiades, or the "Seven Sisters", is made up of hundreds of young, hot stars formed about 100 million years ago and have been vital for scientists to understand how similar clusters form. They also used the stars as a yardstick for estimating the distance to more distant, clusters.
To settle the issue, Melis and his colleagues used a global network of radio telescopes including the Very Long Baseline Array (VLBA), a system of 10 radio telescopes ranging from Hawaii to the Virgin Islands; the Robert C. Byrd Green Bank Telescope in West Virginia; the 1,000-foot-diameter William E. Gordon Telescope of the Arecibo Observatory in Puerto Rico; and the Effelsberg Radio Telescope in Germany.
That gave the equivalent of a telescope the size of the Earth to provide precision measurements. Amy Miouduszewski, of the National Radio Astronomy Observatory, describes the task as "the equivalent of measuring the thickness of a quarter in Los Angeles as seen from New York".
The result? The Pleiades is officially 443 light-years from Earth, a figure, the astronomers say, that is...
Australian scientists are within sight of eradicating the red fox from Phillip Island, south-east of Melbourne, where it has been causing havoc with native animals, particularly the island's fairy penguin – the local name for the little penguin.
Thanks to improvements in control methods there are thought to be less than a dozen foxes there down from more than 200 in 1996.
“In the latter half of the 20th century, nine out of the 10 little penguin colonies on Phillip Island had been wiped out, most likely due to fox predation,” Dr Peter Dann research manager at the island's Nature Parks says.
Foxes were deliberately introduced into Australia in 1855 for recreational hunting but they soon had a devastating effect on native wildlife. The red fox arrived on Phillip Island in 1907 and, despite everything from bounties to hunting, trapping and baiting over the last 60 years, until recently they proved nearly impossible to reduce or remove.
The change came in the early 2000s when researchers began to objectively evaluate control methods which led to a more scientific approach and the aim of eradication.
"A team dedicated to control programmes is absolutely essential," says Dann.
There is an imperative to measure the effectiveness of each method independently of personal biases; and monitoring both predator and prey populations concurrently is vital so the benefits of control can be demonstrated or management can be adapted.
Choosing the right landing site is a complex process. That site must balance the technical needs of the orbiter and lander during all phases of the separation, descent, and landing, and during operations on the surface with the scientific requirements of the 10 instruments on board Philae.
A key issue is that uncertainties in the navigation of the orbiter close to the comet mean that it is only possible to specify any given landing zone in terms of an ellipse – covering up to one square kilometre – within which Philae might land.
Below is a video animation of how the Philae is designed to land on the comet.
"Climate change may ruin the future but it's not likely to mess up your evening," as Steve Davis puts it in the video above.
And that truism is the great get-out clause for politicians. Do nothing, safe in the knowledge you'll be long-gone and enjoying your retirement on a beach someplace by the time the piper has to be paid – even if sea level rises mean that beach was previously halfway up a mountain.
Davis from UC Irvine and Rob Socolow of Princeton University measured how much carbon dioxide has already been "committed" to the atmosphere from existing power plants round the world. The answer? 300 billion tons.*
About two-thirds of these emissions are due to coal-burning stations.
But that figure is just as of today. The "carbon commitment" is growing at 4% a year as new plants are built. As Socolow says
We've been hiding what's going on from ourselves: A high-carbon future is being locked in by the world's capital investments ... the relentlessness of coal-based industrialization [is] long underway and showing no sign of abating.
The carbon dioxide emissions that will come from existing power plants represent a substantial portion of the emissions budget that we need to meet if we are to keep temperature rises at or below 2 degrees – which means we would have to reduce other sources of carbon even more than we thought.
Davis and co-author Robert Socolow of Princeton suggest in their report, published in Environmental Research Letters, that the findings could be used by policymakers to evaluate the long-term climate impacts of current investments in infrastructure.
He says that while many in the West see the brutality and fanaticism as unique to Islamic fundamentalism, the right cocktail of factors can make anyone an extremist. He sees five that could be at play with IS, the first simply that savagery begets savagery.
Callousness, aggression and lack of empathy are common responses by people who have been harshly treated themselves.
When the State breaks down, and with it law and order and civic society, there is only one recourse for survival – the group. Whether defined by religion, racial, political, tribal or clan – or for that matter by the brute dominance of a gang-leader – survival depends on the mutual security offered by the group.
And that can lead to seeing any other group as a dehumanised enemy.
In-group tribalism is strengthened – and loathing for the out-group correspondingly increased – where religion defines the groups. Even when aggression against the other group is self-destructive.
He believes that a culture of revenge can play a part, as can a blind faith in a leader.
The trouble is, as we have seen, when leaders choose to encourage savagery, not quell it, there is nothing hard-wired into human beings to stand up against it.
All that's well and good, I suppose, and some of Robertson's suggested motivations might make sense in the case of an Iraqi Sunni who has been victimised by members of the Shi'ite majority, and clings to a new group for survival in a lawless state as he seeks revenge for his woes.
But there doesn't seem to be much here to explain how a would-be British rap star ends up the prime suspect for cutting off another man's head, or why...
Dinosaurs may have just been unlucky that the catastrophic asteroid collision that is thought to have wiped them out arrived when it did. If it had hit the Earth earlier or later they might have survived, some scientists now think.
Steve Brusatte, a palaeontologist at Edinburgh University, says in a report in Biological Reviewsthat when the impact happened 66 million years ago the Earth had already suffered a dramatic loss of biodiversity and many of the big plant-eating dinosaurs, including the horned triceratops and duck-billed dinosaurs, had already disappeared.
And that meant there were fewer animals for the big meat-eating dinosaurs to prey on.
That made them just that bit less resilient when the asteroid hit what is now Mexico, setting off a disastrous chain of events including tsunamis and earthquakes, and forcing blankets of material into the atmosphere that blocked out the Sun and cooled the Earth by up to 10 degrees.
With ecosystems already weakened the dinosaurs didn't stand a chance, as Brusatte says:
The asteroid almost certainly did it but it just so happened to hit at a bad time when dinosaur ecosystems had been weakened by a loss of diversity. If the asteroid had hit a few million years earlier, or a few million years later, then dinosaurs probably wouldn't have gone extinct.
NASA has marked the 25th anniversary of Voyager 2's fly-past of Neptune in 1989 as the space agency prepares to get up close and personal with Pluto.
This picture of Neptune, above, was taken on 20 August 1989, at a range of 4.4 million miles from the planet. Voyager 2's closest approach to Neptune came four days later on 25 August.
The picture shows the Great Dark Spot and its companion bright smudge; on the west limb the fast moving bright feature called "Scooter" and the little dark spot are visible. North of these, there is a bright cloud band similar to the south polar streak.
NASA is also using the anniversary to set the scene for the climax another mission to the outermost edges of the Solar System in a little under a year when the New Horizons space craft does a similar fly-by of Pluto.
By coincidence, New Horizons passes the orbit of Neptune, its last orbit crossing before beginning its historic exploration of Pluto on the exact 25th anniversary of the Voyager 2 spacecraft’s encounter with the planet.
New Horizons will begin its Pluto exploration in January but the best pictures will come a little later when the spacecraft is at its closest.
New Horizons' Pluto encounter on July 14, 2015, will not be a replay of Voyager but more of a sequel and a reboot, with a new and more technologically advanced spacecraft and, more importantly, a new cast of characters. Those characters are Pluto and its family of five known moons, all of which will be seen up close for the first time next summer.