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Blog Biology 02 September 2014
Yuck! Not French Fries. Boston researchers have shown we can learn to shun unhealthy foods.
ISTOCK

Boston researchers think it may be possible to train the brain to prefer healthy low-calorie foods over unhealthy higher-calorie foods.

"We don't start out in life loving French fries and hating, for example, whole wheat pasta," says Susan Roberts, the senior author of a study by scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University and at Massachusetts General Hospital.

"This conditioning happens over time in response to eating – repeatedly! - what is out there in the toxic food environment."

Scientists have suspected that, once unhealthy food addiction circuits are established, they may be hard or impossible to reverse. To find out whether the brain can be re-trained to support healthy food choices, Roberts and colleagues studied the reward system in 13 overweight and obese men and women, eight of whom were participants in a weight loss program designed by Tufts University researchers and five who were in a control group and not enrolled in the program.

Both groups were given MRI brain scans at the beginning and end of a six-month period. The scans of those people in the weight loss program revealed changes in areas of the brain reward centre associated with learning and addiction. After six months, this area had increased sensitivity to healthy, lower-calorie foods and decreased sensitivity to the unhealthy higher-calorie foods.

"The weight loss program is specifically designed to change how people react to different foods, and our study shows those who participated in it had an increased desire for healthier foods along with a decreased preference for unhealthy foods, the combined effects of which are probably critical for sustainable weight control," says co-author Sai Krupa Das.

Co-corresponding author Thilo Deckersbach, a psychologist at Massachusetts General Hospital, says:

We show here that it is possible to shift preferences from unhealthy food to healthy food without surgery, and that MRI is an...
Blog Space 01 September 2014
NASA/ESA/Alexander Gerst

International Space Station crew member Alexander Gerst shot this time lapse sequence of Orbital's Cygnus cargo vehicle being released on on 15 August 2014.

ESA astronaut Alexander Gerst set up a camera to shoot a series of photographs whilst he and his Expedition 40 colleague NASA's Reid Wiseman operated the Station's robotic arm to manoeuvre the visiting cargo spacecraft into position for release.

A couple of days later, Cygnus, loaded with trash from the ISS, burnt up in Earth's atmosphere over the Pacific Ocean during a planned destructive re-entry – pictured below.

Blog Technology 01 September 2014

Katherine Bourzac at MIT Technology Review has taken a closer look at perovskites, the potential new wonder material that "could lead to commercial solar cells that hit a sweet spot of high performance and low cost".

Certain perovskites can harvest the energy of sunlight very efficiently because they strongly absorb both visible and infrared light. And unlike silicon films, which are made at high temperatures, perovskite films can be made from solution at much lower temperatures. It should be possible to make perovskite solar cells using low-cost, low-energy methods such as printing.

We're not quite there yet as the Bourzac explains. There have been problems in making high quality perovskite solar cells consistently. “When you make 10 different perovskite cells, you get 10 different efficiencies,” says Prashant Kamat, a chemist at the University of Notre Dame in Indiana. “It’s frustrating.”

Nevertheless, it's worth persisting. Some are forecasting 20% efficiency from the materials in the short-term.

A previous post on the potential of perovskites here.

Blog Society 29 August 2014
"Theoretical"
Kyle Karrington / BMC Ecology Image Competition

A Namaqua Rock Mouse snacks on a Pagoda Lily
Petra Wester/BMC Ecology Image Competition (Overall winner)

Online open access research publisher BioMed Central has announced the winners of the BMC Ecology Image Competition, aimed at capturing the beauty of ecological interactions and reflect scientists’ affinity with their subjects.

The winning image, above, catches a Namaqua Rock Mouse feeding on Pagoda Lily pollen.

A black-browed albatross feeds its chick, nesting in dense colonies on the Falkland Islands.
Laetizia Campioni/BMC Ecology Image Competition

Researcher Petra Wester spent many nights on the South African Sevilla rock art trail to study the mouse, and captured the first evidence of the mice pollinating the lily.

The runner up was a touching picture of an albatross feeding her chick. Scientist Laetizia Campioni said: “Albatross parents take great care of their only chick, in which they invest energy and time for six months a year. This picture really touched me and I am really happy now that it has won a prize. It means that the message of this picture is touching for other people, too.”

The BMC Ecology Image Competition was open to everyone affiliated with a research institution, and considered all images that depicted a specific ecological interaction, from photos to data visualizations. The winners were chosen by the journal’s section editors and guest judge, writer and journalist Caspar Henderson, author of Book of Barely Imagined Beings: A 21st Century Bestiary.

In addition to the winner and runner up, the judges chose five section winners reflecting the editorial sections of the journal, and one editors’ pick. The highly commended images reflect the high standard of entries in the competition – it was so hard to choose just eight, the judges wanted to recognize another 22 outstanding images.

The winner of the Behavior category, Bernardo Segura, whose image shows a parasitoid fly attacking an ant said: “I feel that there is so much beauty...

Blog Technology 29 August 2014



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."

Blog Space 29 August 2014
The Pleiades are a cluster of hot young stars that have been crucial to understanding how stars form.
NASA

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...

Blog Society 28 August 2014
A Phillip Island fox can kill more than 30 fairy penguins a night. But the tide is turning.
Phillip Island Nature Parks

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.

“One fox can kill more than 30 penguins a night.”

Researchers this week released a case study of the fight to outfox the foxes in the online version of the CSIRO journal Wildlife Research that they hope will help in other parts of the country.

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.

Blog Space 27 August 2014
The potential landing sites for Philae on the comet 67P/Churyumov-Gerasimenko.
ESA

The European Space Agency has narrowed down to five the possible landing sites for the Rosetta spacecraft's lander Philae on Comet 67P/Churyumov-Gerasimenko.

The survey of potential land sites has only been possible since Rosetta closed in on the comet, giving detailed images of its surface.

The landing is expected to take place in mid-November when the comet is about 450 million km from the Sun. It is currently 522 million km from the Sun, which it takes 6.5 years to orbit.

At their closest approach on 13 August 2015, the comet and Rosetta will be 185 million km from the Sun, meaning an 800% increase in the light received from it.

As the ESA says on the Rosetta website, which also summarises the pros and cons of the different landing sites pictured above,

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.

Blog Climate 27 August 2014



"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.

Well, good luck with that...

*Corrected from earlier version. See comments.