Category Science

Patterned by Nature


Potential Earth-Twin Has Right Temperature for Life

From ScienceNOW, by Govert Schilling

For the first time, astronomers have found a planet smack in the middle of the habitable zone of its sunlike star, where temperatures are good for life. “If this planet has a surface, it would have a very nice temperature of some 70° Fahrenheit [21°C],” says William Borucki of NASA’s Ames Research Center here, who is the principal investigator of NASA’s Kepler space telescope. “[It’s] another milestone on the journey of discovering Earth’s twin,” adds Ames director Simon “Pete” Worden.

Unfortunately, the true nature of the planet, named Kepler-22b, remains unknown. It is 2.4 times the size of Earth, but its mass, and hence its composition, has not yet been determined. “There’s a good chance it could be rocky,” Borucki says, although he adds that the planet would probably contain huge amounts of compressed ice, too. It might even have a global ocean. “We have no planets like this in our own solar system.”

Kepler-22b is 600 light-years away. Every 290 days, it orbits a star that is just a bit smaller and cooler than our own sun. The Kepler telescope, launched in 2009 to scan the skies for Earth-like worlds, found the planet because it sees the orbit edge on. That means that every 290 days, the world transits the surface of the star, blocking out a minute fraction of its light.

Borucki likes to call the new discovery the Christmas planet. “It’s a great gift,” he said at a press conference here this morning. “We were very fortunate to find it.” The first of the three observed transits occurred only days after Kepler started observing. The third one was seen just before Christmas 2010, shortly before the spacecraft was unable to carry out any observations because of a technical glitch. Says Borucki: “We could’ve easily missed it altogether.”

“There are two things really exciting about this planet,” adds Natalie Batalha, Kepler’s deputy science team leader. “It’s right in the middle of the habitable zone [the region around a star where temperatures are neither too high nor too low for liquid water to exist], and it orbits a star very similar to our sun.” Previously discovered “habitable” planets orbited dim, red dwarf stars, or they were located at the edge of the habitable zone, with more extreme temperatures.

At the press conference, which marked the start of the five-day First Kepler Science Conference here at NASA Ames, Batalha also announced 1,094 new planet candidates found by Kepler since February 2011, bringing the total to a whopping 2,326. So far, only 29 of these (including Kepler-22b) have been confirmed to be genuine planets, but Kepler scientists have good reasons to expect that at least 90% of all candidates will turn out to be real.

Forty-eight of these planet candidates orbit in the habitable zone of their parent stars. Most are substantially larger than Earth, but 10 are about the same size as our home planet. Some of these are in multiplanet systems. “It’s conceivable that any — or many — of these 48 habitable zone candidates, or their moons, could have life,” Borucki says.

Jill Tarter of the SETI Institute in Mountain View, Calif., says the habitable Kepler planets are prime targets for the Search for Extra-Terrestrial Intelligence (SETI), carried out with the dedicated 42-dish Allen Telescope Array in Northern California. “We’re taking everything we can get from our Kepler colleagues to look for techno-signatures” that might betray the existence of an alien civilization, she says.

So far, the question about extraterrestrial life is very much open. “We don’t know whether Earth as it is, and life as we know it, is very unusual or very common,” Tarter says. However, if scientists find a second place in the universe where life once got started, it will be obvious that life must be widespread. Says Tarter: “In this field, the number two is important. We count one, two, infinity.”

Image: Artist’s rendition of Kepler-22b (NASA)

How Cycling Benefits the Brain

Via NY Times, by Gretchen Reynolds

To learn more about how exercise affects the brain, scientists in Ireland recently asked a group of sedentary male college students to take part in a memory test followed by strenuous exercise.

First, the young men watched a rapid-fire lineup of photos with the faces and names of strangers. After a break, they tried to recall the names they had just seen as the photos again zipped across a computer screen.

Afterward, half of the students rode a stationary bicycle, at an increasingly strenuous pace, until they were exhausted. The others sat quietly for 30 minutes. Then both groups took the brain-teaser test again.

Notably, the exercised volunteers performed significantly better on the memory test than they had on their first try, while the volunteers who had rested did not improve.

Meanwhile, blood samples taken throughout the experiment offered a biological explanation for the boost in memory among the exercisers. Immediately after the strenuous activity, the cyclists had significantly higher levels of a protein known as brain-derived neurotrophic factor, or BDNF, which is known to promote the health of nerve cells. The men who had sat quietly showed no comparable change in BDNF levels.

For some time, scientists have believed that BDNF helps explain why mental functioning appears to improve with exercise. However, they haven’t fully understood which parts of the brain are affected or how those effects influence thinking. The Irish study suggests that the increases in BDNF prompted by exercise may play a particular role in improving memory and recall.

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The Internet and the Changing Brain

Via BBC Health, by Helen Briggs

Social network sites may be changing people’s brains as well as their social life, research suggests.

Brain scans show a direct link between the number of Facebook friends a person has and the size of certain parts of their brain.

It’s not clear whether using social networks boosts grey matter or if those with certain brain structures are good at making friends, say researchers.

The regions involved have roles in social interaction, memory and autism.

The work, published in the journal Proceedings of the Royal Society B Biological Sciences, looked at 3-D brain scans of 125 university students from London.

Grey matter

Researchers counted the number of Facebook friends each volunteer had, as well as assessing the size of their network of real friends.

A strong link was found between the number of Facebook friends a person had and the amount of grey matter in certain parts of their brain.

The study also showed that the number of Facebook friends a person was in touch with was reflected in the number of “real-world” friends.

“We have found some interesting brain regions that seem to link to the number of friends we have – both ‘real’ and ‘virtual’,” said Dr Ryota Kanai, one of the researchers from University College London.

“The exciting question now is whether these structures change over time. This will help us answer the question of whether the internet is changing our brains.”

One region involved is the amygdala, which is associated with memory and emotional responses.

Previous research has shown a link between the volume of grey matter in the amygdala and the size and complexity of real world social networks. Grey matter is the brain tissue where mental processing takes place.

Three other areas of the brain were linked with the size of someone’s online social network but not their tally of real-world friends.

‘Plastic’ brain

The right superior temporal sulcus has a role in perception and may be impaired in autism. The left middle temporal gyrus is associated with “reading” social cues, while the third – the right entorhinal complex – is thought to be important in memory and navigation.

Professor Geraint Rees, from UCL, who led the research, said little is understood about the impact of social networks on the brain, which has led to speculation the internet is somehow bad for us.

“Our study will help us begin to understand how our interactions with the world are mediated through social networks,” he said.

“This should allow us to start asking intelligent questions about the relationship between the internet and the brain – scientific questions, not political ones.”
Cause and effect

Facebook, the world’s most popular social networking site, has more than 800 million active users around the world. The site allows people to keep in touch with friends, from a handful to a thousand or more.

Dr John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, which funded the study, said: “We cannot escape the ubiquity of the internet and its impact on our lives, yet we understand little of its impact on the brain, which we know is plastic and can change over time.

“This new study illustrates how well-designed investigations can help us begin to understand whether or not our brains are evolving as they adapt to the challenges posed by social media.”

Although the study found a link between human brain structure and online social network size, it did not test cause and effect.

Dr Heidi Johansen-Berg, reader in Clinical Neurology at the University of Oxford’s Centre for Functional MRI of the Brain, said the study found only a weak relationship between the number of Facebook friends and the number of friends in the real world.

“Perhaps the number of Facebook friends you have is more strongly related to how much time you spend on the internet, how old you are, or what mobile phone you have,” she said.

“The study cannot tell us whether using the internet is good or bad for our brains.”

Exoplanet Portraits

From Wired

Direct Images of Other Worlds

Another well-studied planet orbits around Beta Pictoris: a sun-like star 63 light-years away. The planet is estimated to be eight times more massive than Jupiter and orbit at only 8 astronomical units, about the distance between the sun and Saturn. Some data suggests the planet is unusually wide, and one explanation for this would be that it is surrounded by a ring of its own, perhaps making it even more like Saturn.

Because it is much closer to its star than most other directly imaged planets, astronomers have been able to image this exoplanet at many points of its orbit. It was seen once in 2003 and again, on the other side of the star, in 2009. Researchers estimate that the planet should complete its orbit in about 15 years.

Astronomers can also see a dust-free gap around Beta Pictoris. Because the planet is in the middle of the gap, it is suspected of vacuuming up the gas and dust that exists around the young star.

Images: ESO/VLT

Telescope Records Galactic Smash-Up

From Wired, by Dave Mosher

A radio telescope array being built in the highest, driest desert in the world has photographed two colliding galaxies for its first public test shots.

The new images reveal a flurry of star formation within thick clouds of gas and dust at the Antennae Galaxies’ impact zone, 45 million light-years away. Older star-forming regions appear as a faint orange in the image while the youngest — some 3 to 4 million years old — glow bright yellow.

The same murky material that leads to star birth also blocks visible wavelengths of light, but the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile’s high Atacama Desert sees radio wavelengths.

“In the past we couldn’t study them because they were behind the dust. The thing that’s been missing is the youngest stars, which are the most interesting,” said astronomer Brad Whitmore of the Space Telescope Science Institute in a webcast. “This is a beautiful example where we’ll be able to see the full life histories of star clusters.”

Gas and dust absorb the light of stars and then re-emit the energy in different wavelengths of light. Yet like black-out curtains, the thickest molecular dust clouds are too murky for almost any wavelength of light to escape.

Radio wavelengths are an exception. Similar to how curtains or even thick walls don’t absorb all of a local radio station’s broadcast, radio starlight can weave through dense molecular clouds, across the universe and reach human-built telescopes.

Frequencies of radio light that ALMA can detect don’t merely indicate the presence of hot young stars. The light also carries with it rich chemical information about the hearts of star-forming regions.

“For the last 25 years, we have really only relied on being able to see carbon monoxide or hydrogen cyanide,” said astronomer Kartik Sheth of the National Radio Astronomy Observatory in the webcast. “For the first time, we can see the entire chemical spectrum.”

To capture radio wavelengths of light, an international team of scientists and engineers have installed 22 of 66 planned radio antennas, each of which weighs nearly 100 tons and stretches 40 feet in diameter. The last of the $1 billion array’s antennas should be in place by 2013.

By then ALMA should have a resolution able to extract details between eight and 10 times better than any radio telescope on Earth, enough perhaps to peer into planet formation within the Milky Way galaxy.

And because ALMA’s collection area will be 70 percent larger than it is now, astronomers also expect a sensitivity up to 100 times better than other radio telescope arrays. Observers competing for limited time on the array can capture their images more quickly.

“ALMA’s test views of the Antennae show us star-forming regions on a level of detail that no other telescope on Earth or in space has attained,” said astronomer Mark McKinnon, a project manager of the telescope array, in a press release. “This capability can only get much better as ALMA nears completion.”

Visible light images don’t reveal star-creating regions well — there’s too much gas and dust in the way (bottom). Seen in longer-wavelength radiowaves, however, hotspots of star birth shine bright (orange/yellow patches, top). The younger the star birth, the brighter the signal.


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Size Matters: Length of Songbirds’ Playlists Linked to Brain Region Proportions

From PhysOrg

Call a bird “birdbrained” and they may call “fowl.” Cornell University researchers have proven that the capacity for learning in birds is not linked to overall brain size, but to the relative size and proportion of their specific brain regions.

Songbirds with upper brain regions that are larger in relation to lower regions have a greater capacity for learning songs. Higher brain areas control the majority of cognitive and learning functions, while lower brain areas control more motor functions, according to the new study published in the Proceedings of the National Academy of Sciences.

The research shows that when a bird’s higher cortex-like brain area called the high vocal center (HVC) is larger relative to the lower brain area called RA, or if the RA is large relative to an even lower area called N12, the species is able to learn dozens of different notes. Such species as mockingbirds, catbirds, European blackbirds and European warblers can learn hundreds of notes because they have those relative size differences in both sets of areas.

“HVC size by itself only modestly predicts capacity for song learning, but relative size is a very strong predictor,” said Tim DeVoogd, professor of psychology and of neurobiology and behavior and the paper’s senior author. Jordan Moore, a graduate student in DeVoogd’s lab, was the paper’s lead author. “Our work is the first to demonstrate a basic principle of evolution using a specific behavior – having greater cortical control of brain function gives greater behavioral flexibility, including enhanced learning.”

In bird species with great capacities for song learning, higher brain areas likely became built up over lower areas as a result of sexual selection, he said, where females mated with males that had more elaborate songs. Repeated over millions of generations, the structure of the brains of these species changed such that higher brain areas became larger relative to lower areas.

The research suggests that relative brain area sizes may offer a mechanism by which a prominent form of evolution has worked. In birds and perhaps in humans, selection for increased learning capacity may have acted by prolonging the development of the last parts of the brain to grow. Humans are able to speak and to set and achieve complex goals because of prolonged development of higher brain areas, such as the cortex and frontal cortex in particular. These areas of the brain are the last to mature and do not fully develop until humans are in their early 20s, DeVoogd said.

In the study, the researchers collected three males each from 49 common species representing an extensive variety of songbirds from the United States, Europe and South Africa, where each bird was actively singing to attract females as part of his reproductive cycle. They then examined and measured the brain areas.

More information: “Motor pathway convergence predicts syllable repertoire size in oscine birds,” published Sept. 12, 2011 in the Proceedings of the National Academy of Sciences.

Study Finds We Choose Money Over Happiness

From MedicalXpress, by George Lowery

Given the choice, would you take a good-paying job with reasonable demands on your time or a high-paying job with longer work hours, permitting only six hours of sleep? Many people opt for the cash, even when they know their decision will compromise their happiness, according to a new Cornell study.

“You might think of happiness as the ultimate goal that people pursue, but actually, people think of goals like health, family happiness, social status and sense of purpose as sometimes competing with happiness,” said Alex Rees-Jones, a Cornell doctoral student in the field of economics and co-author of a paper to be published in a forthcoming issue of the journal American Economic Review. His co-authors include Cornell assistant professors of economics Dan Benjamin and Ori Heffetz, as well as University of Michigan professor Miles Kimball.

“We found that people make trade-offs between happiness and other things,” Rees-Jones said. “For example, they explicitly told us in the free response sections that they would be happier one way, but their family would be happier if they took higher-paying options.” They also said they were sometimes willing to choose a job that they thought would bring less happiness for themselves if they thought it would generate a greater sense of purpose, higher social status, a greater sense of control or a higher level of their family’s happiness, Rees-Jones said.

The study asked more than 2,600 survey participants (including 633 Cornell students) to consider a variety of scenarios, including the choice between an $80,000 job with reasonable work hours and seven and a half hours of sleep each night, or a $140,000 job with long work hours and time for only six hours of sleep.

Subjects were then asked which option would make them happier.

“On average, there are systematic differences between what people choose and what people think would make them happier,” Rees-Jones said. “For example, people are more likely to choose the higher-income/lower-sleep job even when they don’t think it will make them happier.”

The authors “wanted to see if people were trying to be as happy as possible,” Rees-Jones said.

After the survey, subjects were asked if they thought their responses were in error. “Only 7 percent told us that they thought they were making mistakes,” Rees-Jones said. “When we asked them if they would regret any cases where they had a discrepancy between choice and well-being, 23 percent said yes. In both cases the vast majority said no, it wasn’t a mistake, and no, they wouldn’t regret it.”

“Overall, this indicates that many are willing to pursue a course that sacrifices happiness in favor of other important goals,” said Rees-Jones. “These respondents seem to indicate that maximizing happiness was not perceived to be in their own best interest. However, even if happiness is only one of many goals, it was still the strongest single predictor of choice in our data.”

Say What?

From The Economist

To find new subjects of study, some linguists simply open their front doors

Where in the world is the largest number of different languages spoken? Most linguists would probably plump for New Guinea, an island that has 830 recognised tongues scattered around its isolated, jungle-covered valleys. But a place on the other side of the world runs it close. The five boroughs of New York City are reckoned to be home to speakers of around 800 languages, many of them close to extinction.

New York is also home, of course, to a lot of academic linguists, and three of them have got together to create an organisation called the Endangered Language Alliance (ELA), which is ferreting out speakers of unusual tongues from the city’s huddled immigrant masses. The ELA, which was set up last year by Daniel Kaufman, Juliette Blevins and Bob Holman, has worked in detail on 12 languages since its inception. It has codified their grammars, their pronunciations and their word-formation patterns, as well as their songs and legends. Among the specimens in its collection are Garifuna, which is spoken by descendants of African slaves who made their homes on St Vincent after a shipwreck unexpectedly liberated them; Mamuju, from Sulawesi in Indonesia; Mahongwe, a language from Gabon; Shughni, from the Pamirian region of Tajikistan; and an unusual variant of a Mexican language called Totonac.

Each volunteer speaker of a language of interest is first tested with what is known as a Swadesh list. This is a set of 207 high-frequency, slow-to-change words such as parts of the body, colours and basic verbs like eat, drink, sleep and kill. The Swadesh list is intended to ascertain an individual’s fluency before he is taken on. Once he has been accepted, Dr Kaufman and his colleagues start chipping away at the language’s phonology (the sounds of which it is composed) and its syntax (how its meaning is changed by the order of words and phrases). This sort of analysis is the bread and butter of linguistics.

Every so often, though, the researchers come across a bit of jam. The Mahongwe word manono, for example, means “I like” when spoken soft and flat, and “I don’t like” when the first syllable is a tad sharper in tone. Similarly, mbaza could be either “chest” or “council house”. In both cases, the two words are nearly indistinguishable to an English speaker, but yield starkly different patterns when run through a spectrograph. Manono is a particular linguistic oddity, since it uses only tone to differentiate an affirmative from a negative—a phenomenon the ELA has since discovered applies to all verbs in Mahongwe.

Such niceties are interesting to experts. But the ELA is attempting to understand more than just the nuts and bolts of languages. It is collecting stories and other verbal material specific to the cultures of the participants. One volunteer, for example, wants to write a storybook for children in her language (Shughni), and also a recipe book. That means creating a written form of the language, which the researchers do using what is known as the International Phonetic Alphabet.

Many of Dr Kaufman’s better finds, he says, have come from “hanging out at street corners with a clipboard on Roosevelt Avenue”—a street (pictured above) in the borough of Queens that he describes as the “epicentre of the epicentre” of linguistic New York. How long it will remain so is moot. The world’s languages, which number about 6,900, are reckoned to be dying out at the rate of one a fortnight. The reason is precisely the sort of cultural mixing that New York epitomises. The value of learning any particular language is increased by the number of people who already speak it. Conversely, the value of a minority language is diminished as people abandon it. To those languages that hath, in other words, shall be given. From those that hath not, shall the last speakers soon be taken away.

Winning Astronomy Photos of 2011

Via National Geographic

Fighting Dragons of Ara
Photograph by Michael Sidonio

Known as the fighting dragons of Ara, two colorful gas clouds appear to be posing in attack position in a picture that received honorable mention in the “Deep Sky” category.

Australian astroimager Michael Sidonio captured subtle hues of purple, orange, and green from the giant cloud of gas and dust, which sits 4,000 light-years from Earth in the southern constellation of Ara.

The 300-light-year-wide molecular cloud is being shaped by radiation from massive young stars formed inside during the past few million years.

Vela Supernova Remnant
Photograph by Marco Lorenzi

Hanging off one of the wings of the constellation Cygnus, the swan, is the nebulous Vela supernova remnant—all that remains of a star that exploded 12,000 years ago.

The cobweb-like structure, which lies more than 800 light-years from Earth, is seen expanding across a field of stars in this picture by Marco Lorenzi in Italy, winner of the “Deep Space” category.

“I’ve always been inspired by supernova remnants, in particular by their reach and their different compositions. After all, several of the building bricks of life are created during these apocalyptic events,” Lorenzi said in a press statement.

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