Hubble image: Galaxy Cluster Abell 1413 Between the Lion and Berenice's Hair

Galaxy cluster Abell 1413 lies between the constellations of Leo (The Lion) and Coma Berenices (Berenice's Hair), at a distance of over 2 billion light-years from Earth. 

A large, very elliptical galaxy called MCG+04-28-097 shines at the center of this image, with a halo of stars extending outward more than 6.5 million light-years.

Abell 1413 contains more than 300 galaxies bound together by the immense gravity of the cluster.

Abell 1413 is part of the Abell catalogue, a collection of over 4000 rich clusters of galaxies fairly close to Earth, at least from a cosmological perspective, their light took less than 3 billion years to reach us.

The clusters are called rich due to the huge number of galaxies they play host to. Abell 1413 is observed to contain more than 300 galaxies held together by the immense gravity of the cluster.

The strong interactions between these galaxies cause the material in the cluster to be heated to extremely high temperatures of almost 100 million degrees, because of this, the cluster emits very strong X-ray radiation.

Visible distortions in the image can be seen in the form of arcs, caused by gravitational lensing.

MIT THAW: Direct interaction between Smartphones, screens and electronic devices

MIT researchers with the Tangible Media Group and the Fluid Interface Group have come up with a smartphone system called THAW that allows a smartphone user to seamlessly interact with other computer devices via their screen.

The system is meant to bridge the gap that exists between user devices, transferring files between phones and a desktop computer for example (by placing the phone on the larger screen and dragging icons to the phone) or continuing to play a video game started on a console on a mobile device.

The same system allows for using a smartphone as a peripheral device, moving files on a computer screen for example, or manipulating images.

It's all a demonstration of a larger effort to integrate all the various devices that people are using, team members told the media recently.

Letting users transfer songs, videos or other files without menus or Bluetooth devices, or allowing for uninterrupted activities.

Imagine watching the news on your television in the morning, pressing your phone against the screen, then walking out the door as the news program continues in your hand, that's true integration.

It introduces a new concept level, whereby devices become aware of not just what is being shown on a display device, but what is happening underneath to deliver that imagery.

THAW works by projecting a grid onto an underlying video screen, and then using it to orient itself.

Imagery is brought into the smartphone via its camera, where software takes over, recognizing what is happening and then launching a companion application or software meant to manipulate objects on the underlying device.

NASA WISE: Coldest brown dwarfs blur lines between stars and planets

This artist's conception portrays a free-floating brown dwarf, or failed star. 

A new study shows that several of these objects are warmer than previously thought with temperatures about 250-350 degrees Fahrenheit. 

Credit: NASA/JPL-Caltech

Astronomers are constantly on the hunt for ever-colder star-like bodies, and two years ago a new class of such objects was discovered by researchers using NASA's WISE space telescope.

However, until now no one has known exactly how cool their surfaces really are - some evidence suggested they could be room temperature.

A new study shows that while these brown dwarfs, sometimes called failed stars, are indeed the coldest known free-floating celestial bodies, they are warmer than previously thought with temperatures about 250-350 degrees Fahrenheit.

To reach such low surface temperatures after cooling for billions of years means that these objects can only have about 5 to 20 times the mass of Jupiter.

Unlike the Sun, these objects' only source of energy is from their gravitational contraction, which depends directly on their mass.

Trent Dupuy

"If one of these objects was found orbiting a star, there is a good chance that it would be called a planet," says Trent Dupuy, a Hubble Fellow at the Harvard-Smithsonian Center for Astrophysics.

But because they probably formed on their own and not in a proto-planetary disk, astronomers still call these objects brown dwarfs even if they are "planetary mass."

Characterizing these cold brown dwarfs is challenging because they emit most of their light at infrared wavelengths, and they are very faint due to their small size and low temperature.

To get accurate temperatures, astronomers need to know the distances to these objects.

"We wanted to find out if they were colder, fainter, and nearby or if they were warmer, brighter, and more distant," explains Dupuy.

Using NASA's Spitzer Space Telescope, the team determined that the brown dwarfs in question are located at distances 20 to 50 light-years away.

Locations of brown dwarfs: The locations of brown dwarfs discovered by NASA's Wide-field Infrared Survey Explorer, or WISE, and mapped by NASA's Spitzer Space Telescope, are shown here in this diagram. 

The view is from a vantage point about 100 light-years away from the sun, looking back towards the constellation Orion. 

At this distance our sun is barely visible as a speck of light. The vastly fainter brown dwarfs would not even be visible in this view. The red lines all link back to the location of the sun. 

Credit: NASA/JPL-Caltech

To determine the distances to these objects the team measured their parallax - the apparent change in position against background stars over time.

As the Spitzer Space Telescope orbits the Sun its perspective changes and nearby objects appear to shift back and forth slightly.

The same effect occurs if you hold up a finger in front of your face and close one eye and then the other. The position of your finger seems to shift when viewed against the distant background.

The new data also present new puzzles to astronomers that study cool, planet-like atmospheres. Unlike warmer brown dwarfs and stars, the observable properties of these objects don't seem to correlate as strongly with temperature.

This suggests increased roles for other factors, such as convective mixing, in driving the chemistry at the surface.

This study examined the initial sample of the coldest brown dwarfs discovered in the WISE survey data.

Additional objects discovered in the past two years remain to be studied and will hopefully shed light on some of these outstanding issues.

Depression Stems from Miscommunication Between Brain Cells; Study Challenges Role of Serotonin in Depression

A new study from the University of Maryland School of Medicine suggests that depression results from a disturbance in the ability of brain cells to communicate with each other. 

Credit: © Artur Golbert / Fotolia

A new study from the University of Maryland School of Medicine suggests that depression results from a disturbance in the ability of brain cells to communicate with each other.

The study indicates a major shift in our understanding of how depression is caused and how it should be treated. Instead of focusing on the levels of hormone-like chemicals in the brain, such as serotonin, the scientists found that the transmission of excitatory signals between cells becomes abnormal in depression.

Scott M. Thompson

The research, by senior author Scott M. Thompson, Ph.D., Professor and Interim Chair of the Department of Physiology at the University of Maryland School of Medicine, was published online in the March 17 issue of Nature Neuroscience.

According to the Centers for Disease Control and Prevention, between 2005 and 2008, approximately one in 10 Americans were treated for depression, with women more than twice as likely as men to become depressed.

The most common antidepressant medications, such as Prozac (Fluoxetine), Zoloft (Setraline) and Celexa (Citalopram), work by preventing brain cells from absorbing serotonin, resulting in an increase in its concentration in the brain.

Unfortunately, these medications are effective in only about half of patients. Because elevation of serotonin makes some depressed patients feel better, it has been thought for over 50 years that the cause of depression must therefore be an insufficient level of serotonin.

The new University of Maryland study challenges that long-standing explanation.

"Dr. Thompson's groundbreaking research could alter the field of psychiatric medicine, changing how we understand the crippling public health problem of depression and other mental illness," says E. Albert Reece, M.D., Ph.D., M.B.A., Vice President for Medical Affairs at the University of Maryland and John Z. and Akiko K. Bowers Distinguished Professor and Dean at the University of Maryland School of Medicine.

"This is the type of cutting-edge science that we strive toward at the University of Maryland, where discoveries made in the laboratory can impact the clinical practice of medicine."

Depression affects more than a quarter of all U.S. adults at some point in their lives, and the World Health Organization (WHO) predicts that by 2020 it will be the second leading cause of disability worldwide.

Depression is also the leading risk factor for suicide, which causes twice as many deaths as murder, and is the third leading cause of death for 15-24 year olds.

The first major finding of the study was the discovery that serotonin has a previously unknown ability to strengthen the communication between brain cells.

"Like speaking louder to your companion at a noisy cocktail party, serotonin amplifies excitatory interactions in brain regions important for emotional and cognitive function and apparently helps to make sure that crucial conversations between neurons get heard," says Dr. Thompson.

"Then we asked, does this action of serotonin play any role in the therapeutic action of drugs like Prozac?"

To understand what might be wrong in the brains of patients with depression and how elevating serotonin might relieve their symptoms, the study team examined the brains of rats and mice that had been repeatedly exposed to various mildly stressful conditions, comparable to the types of psychological stressors that can trigger depression in people.

The researchers could tell that their animals became depressed because they lost their preference for things that are normally pleasurable.

For example, normal animals given a choice of drinking plain water or sugar water strongly prefer the sugary solution. Study animals exposed to repeated stress, however, lost their preference for the sugar water, indicating that they no longer found it rewarding.

This depression-like behaviour strongly mimics one hallmark of human depression, called anhedonia, in which patients no longer feel rewarded by the pleasures of a nice meal or a good movie, the love of their friends and family, and countless other daily interactions.

A comparison of the activity of the animals' brain cells in normal and stressed rats revealed that stress had no effect on the levels of serotonin in the 'depressed' brains.

Instead, it was the excitatory connections that responded to serotonin in strikingly different manner. These changes could be reversed by treating the stressed animals with antidepressants until their normal behaviour was restored.

"In the depressed brain, serotonin appears to be trying hard to amplify that cocktail party conversation, but the message still doesn't get through," says Dr. Thompson.

Using specially engineered mice created by collaborators at Johns Hopkins University School of Medicine, the study also revealed that the ability of serotonin to strengthen excitatory connections was required for drugs like antidepressants to work.

Sustained enhancement of communication between brain cells is considered one of the major processes underlying memory and learning.

The team's observations that excitatory brain cell function is altered in models of depression could explain why people with depression often have difficulty concentrating, remembering details, or making decisions.

Additionally, the findings suggest that the search for new and better antidepressant compounds should be shifted from drugs that elevate serotonin to drugs that strengthen excitatory connections.

"Although more work is needed, we believe that a malfunction of excitatory connections is fundamental to the origins of depression and that restoring normal communication in the brain, something that serotonin apparently does in successfully treated patients, is critical to relieving the symptoms of this devastating disease," Dr. Thompson explains.

The above story is reprinted from materials provided by University of Maryland Medical Center.

Missing Link Between Solar Activity and The UK's Cold Winters

A link between low solar activity and jet streams over the Atlantic could explain why, despite global warming trends, people in regions North East of the Atlantic Ocean might need to brace themselves for more frequent cold winters in years to come.

A new report published in IOP Publishing's Environmental Research Letters describes how we are moving into an era of lower solar activity which is likely to result in UK winter temperatures more like those seen at the end of the seventeenth century.

Lead author Mike Lockwood of the University of Reading said: "This year's winter in the UK has been the 14th coldest in the last 160 years and yet the global average temperature for the same period has been the 5th highest. We have discovered that this kind of anomaly is significantly more common when solar activity is low."

The new paper, 'Are cold winters in Europe associated with low solar activity?', differs from previous efforts to explain the UK's recent cold winters by comparing the most comprehensive, but regionally specific, temperature dataset available (the Central England Temperature dataset) to the long-term behaviour of the Sun's magnetic field, and to trends across the entire Northern Hemisphere.

The paper is being published now as the researchers have just had the opportunity to put this year's data to the test and found that this year's results fit well with the trends they have discovered.

Jupiter: Difference Between Ganymede And Callisto

The Difference Between Ganymede And Callisto

Jupiter (right) and the Galilean satellites (right to left) Io, Europa, Ganymede, and Callisto. Cutaways show the interior states of Ganymede and Callisto after many impacts by icy planetesimals during the late heavy bombardment. Colors represent density, with black showing the rocky core (with a density 3 g/cm^3), blue showing mixed ice and rock (densities 1.8 to 1.9 g/cm^3) and white showing rock-free ice.

Differences in the number and speed of cometary impacts onto Jupiter's large moons Ganymede and Callisto some 3.8 billion years ago can explain their vastly different surfaces and interior states, according to research by scientists at the Southwest Research Institute appearing online in Nature Geoscience Jan. 24, 2010.

Ganymede and Callisto are similar in size and are made of a similar mixture of ice and rock, but data from the Galileo and Voyager spacecraft show that they look different at the surface and on the inside. A conclusive explanation for the differences between Ganymede and Callisto has eluded scientists since the Voyager Jupiter encounters 30 years ago.

Dr. Amy C. Barr and Dr. Robin M. Canup of the SwRI Planetary Science Directorate created a model of melting by cometary impacts and rock core formation to show that Ganymede and Callisto's evolutionary paths diverged about 3.8 billion years ago during the Late Heavy Bombardment, the phase in lunar history dominated by large impact events.

"Impacts during this period melted Ganymede so thoroughly and deeply that the heat could not be quickly removed. All of Ganymede's rock sank to its center the same way that all the chocolate chips sink to the bottom of a melted carton of ice cream," says Barr. "Callisto received fewer impacts at lower velocities and avoided complete melting."