Monthly Archives: September 2015

Positive People Have Different Brain Connections

There is a strong correspondence between a particular set of connections in the brain and positive lifestyle and behaviour traits, according to a new study by Oxford University researchers.

A team of scientists led by the University’s Centre for Functional MRI of the Brain has investigated the connections in the brains of 461 people and compared them with 280 different behavioural and demographic measures that were recorded for the same participants. They found that variation in brain connectivity and an individual’s traits lay on a single axis — where those with classically positive lifestyles and behaviours had different connections to those with classically negative ones. The findings are published in Nature Neuroscience.

 

The team used data from the Human Connectome Project (HCP), a $30m NIH-funded brain imaging study led by Washington, Minnesota and Oxford Universities. The HCP is pairing up functional MRI scans of 1,200 healthy participants with in-depth data gained from tests and questionnaires. “The quality of the imaging data is really unprecedented,” explains Professor Stephen Smith, who was the lead author of the paper. “Not only is the number of subjects we get to study large, but the spatial and temporal resolution of the fMRI data is way ahead of previous large datasets.” So far, data for 500 subjects have been released to researchers for analysis.

The Oxford team took the data from 461 of the scans and used it to create an averaged map of the brain’s processes across the participants. “You can think of it as a population-average map of 200 regions across the brain that are functionally distinct from each other,” explains Professor Smith. “Then, we looked at how much all of those regions communicated with each other, in every participant.”

The result is a connectome for every subject: a detailed description of how much those 200 separate brain regions communicate with each other, which can be thought of as a map of the brain’s strongest connections. The team then added the 280 different behavioural and demographic measures for each subject and performed a ‘canonical correlation analysis’ between the two data sets — a mathematical process that can unearth relationships between the two large sets of complex variables.

They found one strong correlation that relates specific variations in a subject’s connectome with their behavioural and demographic measures. Interestingly, the correlation shows that those with a connectome at one end of scale score highly on measures typically deemed to be positive, such as vocabulary, memory, life satisfaction, income and years of education. Meanwhile, those at the other end of the scale were found to exhibit high scores for traits typically considered negative, such as anger, rule-breaking, substance use and poor sleep quality.

The researchers point out that their results resemble what psychologists refer to as the ‘general intelligence g-factor': a variable first proposed in 1904 that’s sometimes used to summarize a person’s abilities at different cognitive tasks. While the new results include many real-life measures not included in the g-factor — such as income and life satisfaction, for instance — those such as memory, pattern recognition and reading ability are strongly mirrored.

Proponents of the g-factor point out that many intelligence-related measures are inter-related — suggesting that if you’re good at one thing, you’re likely to be good at the others, too. However, in the past, the g-factor has also received some criticism, partly because it is not necessarily clear if these correlations between different cognitive abilities are truly reflecting correlations between distinct underlying brain circuits. The new results, however, may provide an opportunity to understand if that’s correct, or if the processes in the brain tell a more complex story.

“It may be that with hundreds of different brain circuits, the tests that are used to measure cognitive ability actually make use of different sets of overlapping circuits,” explains Professor Smith. “We hope that by looking at brain imaging data we’ll be able to relate connections in the brain to the specific measures, and work out what these kinds of test actually require the brain to do.”

 

Source- sciencedaily.com

Liquid water flows on today’s Mars: NASA confirms evidence

New findings from NASA’s Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.

 

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening.

“We found the hydrated salts only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration. In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks,” said Lujendra Ojha of the Georgia Institute of Technology (Georgia Tech) in Atlanta, lead author of a report on these findings published Sept. 28 by Nature Geoscience.

Ojha first noticed these puzzling features as a University of Arizona undergraduate student in 2010, using images from the MRO’s High Resolution Imaging Science Experiment (HiRISE). HiRISE observations now have documented RSL at dozens of sites on Mars. The new study pairs HiRISE observations with mineral mapping by MRO’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).

The spectrometer observations show signatures of hydrated salts at multiple RSL locations, but only when the dark features were relatively wide. When the researchers looked at the same locations and RSL weren’t as extensive, they detected no hydrated salt.

Ojha and his co-authors interpret the spectral signatures as caused by hydrated minerals called perchlorates. The hydrated salts most consistent with the chemical signatures are likely a mixture of magnesium perchlorate, magnesium chlorate and sodium perchlorate. Some perchlorates have been shown to keep liquids from freezing even when conditions are as cold as minus 94 degrees Fahrenheit (minus 70 Celsius). On Earth, naturally produced perchlorates are concentrated in deserts, and some types of perchlorates can be used as rocket propellant.

Perchlorates have previously been seen on Mars. NASA’s Phoenix lander and Curiosity rover both found them in the planet’s soil, and some scientists believe that the Viking missions in the 1970s measured signatures of these salts. However, this study of RSL detected perchlorates, now in hydrated form, in different areas than those explored by the landers. This also is the first time perchlorates have been identified from orbit.

MRO has been examining Mars since 2006 with its six science instruments.

“The ability of MRO to observe for multiple Mars years with a payload able to see the fine detail of these features has enabled findings such as these: first identifying the puzzling seasonal streaks and now making a big step towards explaining what they are,” said Rich Zurek, MRO project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

For Ojha, the new findings are more proof that the mysterious lines he first saw darkening Martian slopes five years ago are, indeed, present-day water.

“When most people talk about water on Mars, they’re usually talking about ancient water or frozen water,” he said. “Now we know there’s more to the story. This is the first spectral detection that unambiguously supports our liquid water-formation hypotheses for RSL.”

The discovery is the latest of many breakthroughs by NASA’s Mars missions.

“It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”

 

 

Source- sciencedaily.com

No, the super blood moon isn’t a harbinger of the apocalypse

For many people, the sight of the Moon turning deep red – some would say blood red – during a lunar eclipse is a wonderful sight. And that’s precisely what many millions of sky gazers will be able to see this Sunday or Monday, depending on their location on Earth.

But for a dedicated few, this is a sign of something much more terrifying: nothing less than the apocalypse itself.

Lunar eclipses are an impressive and visible reminder that the night sky isn’t a static backdrop but a dynamic show filled with worlds that