Dogs Communicate with Wag of a Tail

Posted November 1st, 2013 at 8:06 pm (UTC+0)
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A dog wagging its tail (Bill McChesney via Creative Commons @ Flickr)

(Bill McChesney via Creative Commons @ Flickr)

The direction in which a dog wags its tail can communicate its emotional state to other canines, according to a new study published in Current Biology.

The Italian research team behind the study says dogs recognize, and respond accordingly, whether other canines wag their tails to the right or to the left.

The reason dogs understand the right versus left tail wag, according to the researchers, is because they have asymmetrically organized brains, meaning that the left and right sides of our brains are each responsible for controlling different things, much like humans.

In an earlier study, the researchers found dogs tend to wag their tails to the right when they feel positive, such as when they see their owners. Dogs wag their tails to the left when they experience negative emotions, such as feelings that might be triggered by an unfriendly dog or some other kind of danger.

The researchers say that this left and right tail wagging behavior is because of what’s taking place in the canine’s brains. A wag to the right is brought on by activation on the left side of its brain, while activity in the right side of the brain produces a wag to the left.

While this right versus left wagging behavior means something to other dogs, the researchers say that they’re probably not purposely displaying this behavior to communicate with each other.  Instead they say it’s just an automatic response due to left side or right side brain activation. But the team also points out that this behavior could serve a very helpful purpose to people like dog owners and veterinarians as another way to better understand what’s going on with the animal.

Compilation of videos shown to test dogs – left, right, no tail wagging – (Current Biology, Siniscalchi et al.)

To make their findings the researchers showed their dog subjects videos of other dogs either wagging their tails to the left or right. When the test dogs saw a video of a dog wagging its tail to the left, their heart rates increased and they appeared a bit nervous. However, when the dogs saw another animal wagging its tail to the right, they remained calm.

“The direction of tail wagging does in fact matter, and it matters in a way that matches hemispheric activation,” said Giorgio Vallortigara of the Center for Mind/Brain Sciences of the University of Trento. “In other words, a dog looking to a dog wagging with a bias to the right side—and thus showing left-hemisphere activation as if it was experiencing some sort of positive/approach response—would also produce relaxed responses. In contrast, a dog looking to a dog wagging with a bias to the left—and thus showing right-hemisphere activation as if it was experiencing some sort of negative/withdrawal response—would also produce anxious and targeting responses as well as increased cardiac frequency. That is amazing, I think.”

US, India Prep for Unmanned Missions to Mars

Posted October 29th, 2013 at 5:36 pm (UTC+0)
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The planet Mars in late spring as imaged by the Hubble Space Telescope (NASA/JPL/California Institute of Technology)

The planet Mars in late spring as imaged by the Hubble Space Telescope (NASA)

Both the United States and India are gearing up for unmanned missions to Mars.

India will launch its first interplanetary spacecraft when the Indian Space Research Organization (ISRO) sends its Mars Orbiter Mission (MOM) to the Red Planet on Nov. 5. The spacecraft will be launched from the Satish Dhawan Space Centre located in Sriharikota, Andhra Pradesh, India.

According to ISRO, one of MOM’s main objectives is to allow the Indian space program to develop the technologies required to design, plan, manage and operate an interplanetary mission.

Once the MOM spacecraft arrives at Mars in September 2014, it will drop into orbit around the planet. Throughout its nearly year-long mission the MOM will explore the Martian surface and atmosphere.

India's Mars Orbiter Mission Spacecraft being integrated to the 4th stage of of its launch vehicle. (Indian Space Research Organization)

India’s Mars Orbiter Mission Spacecraft being integrated to the 4th stage of of its launch vehicle. (Indian Space Research Organization)

Meanwhile, NASA is making final preparations to launch a new unmanned mission to Mars that will allow scientists on Earth to examine the Red Planet’s atmosphere in greater detail.

Lift-off for the Mars Atmosphere and Volatile Evolution mission (MAVEN) is currently scheduled on Monday, Nov. 18 from Cape Canaveral Air Force Station in Florida.

In the course of its one-Earth-year primary mission, MAVEN will study the specific processes that led to Mars losing much of its atmosphere about 3.5 billion years ago.

Data sent back to Earth from MAVEN should help scientists gain a greater understanding of climate change on the Red Planet and learn more of the history of planetary habitability.

“The MAVEN mission is a significant step toward unraveling the planetary puzzle about Mars’ past and present environments,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “The knowledge we gain will build on past and current missions examining Mars and will help inform future missions to send humans to Mars.”

Artist's concept of the MAVEN spacecraft orbiting Mars. (NASA/Goddard Space Flight Center)

Artist’s concept of the MAVEN spacecraft orbiting Mars. (NASA)

Once it arrives at Mars, also in September 2014, and eases into its elliptical science orbit, the MAVEN will observe all of the Red Planet’s latitudes.  The spacecraft is expected to cruise around Mars at an altitude of between 158 and 6,115 km above its surface.

During its mission, MAVEN will also perform five of what NASA calls “deep dip maneuvers,” that will send the spacecraft down to an altitude of only 125 km above the surface of Mars, which scientists say is the lower boundary of the planet’s upper atmosphere.

ISRO said that NASA and its Jet Propulsion Laboratory will also provide communications and navigation support to the Indian MOM mission.

Gene Enhancers Give Human Face Its Final Look

Posted October 25th, 2013 at 8:19 pm (UTC+0)
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Every human face is as unique as a fingerprint (National Cancer Institute)

Each human face is as unique as a fingerprint. (National Cancer Institute)

When you look at yourself in the mirror, do you ever wonder why you look the way you do?  Do you also wonder what biological processes were at work when it came time to shape and sculpt your face, which is as individual and unique as a fingerprint?

The answer is in a little snippet of your DNA called a gene enhancer, according to scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab)

These little pieces of DNA help switch on, or boost the expression of specific genes that control the development of the face and head while in utero. What’s interesting about these little influential bits of DNA is that a gene enhancer doesn’t have to be found anywhere close to the genes it works on and, in some cases, doesn’t even have to be located on the same chromosome.

Of course, there are a number of hereditary factors, such as when a child resembles a parent, that help determine appearance. The researchers, who outlined their findings in the journal “Science,” said the gene enhancer fine-tunes the genetics to give your face its final unique look. Even with identical twins, there are subtle differences in appearance.

Identical twins Linda and Terry Jamison look similar but are not exactly the same in appearance.  Look for the differences. (Linda and Terry Jamison via Wikimedia Commons)

Identical twins Linda and Terry Jamison look similar but are not exactly the same in appearance.  (Linda and Terry Jamison via Wikimedia Commons)

“Our results suggest it is likely there are thousands of enhancers in the human genome that are somehow involved in craniofacial development,” said Axel Visel, a geneticist with Berkeley Lab’s Genomics Division, who led the research. “We don’t know yet what all of these enhancers do, but we do know that they are out there and they are important for craniofacial development.”

Scientists have previously been able to identify some of the genetic flaws that can cause birth defects, such as a cleft lip or palate, but haven’t been able to fully understand what genetic factors are responsible for normal, subtle differences in appearance.

In the past, Visel and his colleagues were able to map gene enhancers in the heart, brain and other vital organs. The researchers said their studies showed that gene enhancers can control their targets from across distances of hundreds of thousands of base pairs, which are each two chemical bases that scientists consider to be the fundamental components of the DNA double helix.

To find out if these gene enhancers have the same type of long-distance effect on the development of the head and face, the researchers studied transgenic mice or those that had been genetically modified.

They were able to identify more than 4,000 possible gene enhancer sequences they think play a role in fine-tuning the genes responsible for developing and defining the head and face.

Berkeley Lab researchers identified distant-acting transcriptional enhancers in the developing craniofacial structure.  Changes in appearance made by removing one of these enhancers shown in red. (Berkeley Labs)

Berkeley Lab researchers identified distant-acting transcriptional enhancers in the developing craniofacial structure. The changes in appearance made by removing one of these enhancers are shown in red. (Berkeley Labs)

A later analysis of their data showed that removing a few of these individual craniofacial enhancers can cause changes to the shape of the head and/or face.

“Our results also offer an opportunity for human geneticists to look for mutations specifically in enhancers that may play a role in birth defects, which in turn may help to develop better diagnostic and therapeutic approaches,” said Visel.

While the researchers continue their own research, they are also working with geneticists to carry out specialized searches to look for mutations within the enhancer sequences of humans with craniofacial birth defects.

Study Suggests a Significant Change to Human History

Posted October 18th, 2013 at 6:40 pm (UTC+0)
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This is "Skull 5" that was found at the Dmanisi, Georgia dig site. (Georgian National Museum)

This is “Skull 5″ that was found at the Dmanisi, Georgia dig site. (Georgian National Museum)

An international team of scientists claim that their recent research could rewrite the history of human evolution.

The researchers suggest that instead of our early human ancestors belonging to different evolutionary species such as Homo habilis, Homo rudolfensis or Homo erectus, they are all actually of the same species, but just happen to look a bit different from each another.

Writing in the journal Science, the scientists from Georgia, Switzerland, Israel and the U.S. came to their conclusions after studying a 1.8-million-year-old skull from the early Pleistocene epoch that was unearthed in Dmanisi, Georgia.

According to the researchers, the skull they studied, called Skull 5, is not like other fossils of the Homo genus.  Skull 5, they said, reveals a combination of a braincase that’s about 546 cubic centimeters along with a long face and large teeth.

Despite having limb proportions and the body size of a modern human, the researchers said that the small braincase of Skull 5 indicates that this early human ancestor had a small brain.

The skull was found with the remains of four other human ancestors along with other material that included an assortment of animal fossils and some stone tools.

Dmanisi, Georgia excavation site circa 2007 (Georgian National Museum)

Dmanisi, Georgia excavation site circa 2007 (Georgian National Museum)

The researchers said this was a unique find since all of the unearthed material could be associated with the same time period and location.

In examining and analyzing “Skull 5”, the researchers said that they found that the differences between the various fossils were no more noticeable than those between five modern humans or five chimpanzees.

“Had the braincase and the face of Skull 5 been found as separate fossils at different sites in Africa, they might have been attributed to different species,” said Christoph Zollikofer from the Anthropological Institute and Museum in Zurich, Switzerland and a co-author of the report. “That’s because Skull 5 unites some key features, like the tiny braincase and large face, which had not been observed together in an early Homo fossil until now.”

Researchers previously have typically considered variations among Homo fossils as an indication that they were of different species.

But those involved with this recent study say that their findings suggest that fossils of various early members of the human family, all originating in Africa, are part of one evolving lineage, probably what is known as Homo erectus. Previous research indicates that this now extinct hominid lived as recently as 143,000 to about 1.8 million years ago.

Study suggests that other human ancestor species may actually belong to the species Homo erectus seen here in this reconstruction. (Westfälisches Landesmuseum via Wikimedia Commons)

Study suggests that other human ancestor species may actually belong to the species Homo erectus seen here in this reconstruction. (Westfälisches Landesmuseum via Wikimedia Commons)

“[The Dmanisi finds] look quite different from one another, so it’s tempting to publish them as different species,” explained Zollikofer. “Yet we know that these individuals came from the same location and the same geological time, so they could, in principle, represent a single population of a single species.”

Checking the African fossil record, the researchers said that they also noticed a similar pattern and range of variation in the African fossil record so they figured that it was safe to assume that there was a single Homo species at that time in Africa too.

Furthermore, the researchers also found that since the hominid fossils recovered from the Dmanisi site are so similar to those found in Africa, they theorize that they are also both of the same species.

While the Georgian dig site is already providing opportunities for researchers to “compare and contrast” the physical characteristics of a number of human ancestors that happened to be in the same place and time, scientists expect even more evidence to be uncovered, since the site has only been partially excavated.

Scientists Make Progress on Artificial Limbs That Can Feel

Posted October 15th, 2013 at 6:13 pm (UTC+0)
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(PNAS, 2013)

(PNAS, 2013)

Chicago researchers have made significant progress developing prosthetic limbs that can feel and touch.

Writing in the Proceedings of the National Academy of Sciences, the researchers say they’ve established a foundation to develop touch-sensitive prosthetic limbs.

This research could lead to a direct interface with the brain that could someday allow those who have lost limbs to, not only manipulate objects, but also to be able to touch and feel again.

“To restore sensory motor function of an arm, you not only have to replace the motor signals that the brain sends to the arm to move it around, but you also have to replace the sensory signals that the arm sends back to the brain,” said  Sliman Bensmaia of the University of Chicago. “We think the key is to invoke what we know about how the brain of the intact organism processes sensory information, and then try to reproduce these patterns of neural activity through stimulation of the brain.”

The research by the Chicago team is part of a project, under way since 2006, called Revolutionizing Prosthetics at the Defense Advanced Research Projects Agency (DARPA).  Researchers hope to create a modular artificial upper limb that will restore an amputee’s natural motor control and sensation.

The work being done by the Chicago research team focuses on developing the sensory aspects of the prosthetic limbs. Their experiments have been conducted with monkeys since the animals’ sensory systems are similar to humans.

The researchers said  they’ve been able to identify patterns of neural activity which occur when an object is being manipulated and then artificially replicate those patterns.

In their first experiment, the researchers wanted to learn more about sensing where the skin was touched. They trained the test monkeys to recognize several types of physical contact with their fingers and then connected electrodes to parts of the monkey’s brains related to each of their fingers. Instead of using actual physical touches, they substituted them with electrical stimulation directed to those specific areas of their brains. As a result, the researchers found that the monkeys reacted to the electrical stimulation the same way they did with actual physical contact.

Experiments were conducted on rhesus macaque monkeys, such as the one in this picture taken at Kinnerasani Wildlife Sanctuary, Andhra Pradesh, India. (J.M. Garg/Wikimedia Commons)

Experiments were conducted on rhesus macaque monkeys, such as the one in this picture taken at Kinnerasani Wildlife Sanctuary, Andhra Pradesh, India. (J.M. Garg/Wikimedia Commons)

The next area the researchers wanted to concentrate on was sense of pressure on the skin. They came up with an algorithm that would produce the proper amount of electrical current to artificially produce the sensation of pressure. As in their first experiment, the researchers found  their test animals responded the same way whether the sensation was actually felt through their fingers or reproduced artificially.

Finally, the researchers looked into the natural sensations that are felt when a hand first touches or releases an object. Since this series of events also produces bursts of activity in the brain, the research team was able to provide direct stimulation to the brain that also duplicated those sensations.

The experiments helped the scientists develop computer instructions to be incorporated into a robotic prosthetic arm.  They said that these instructions, working with the robotic appendage and through a neural interface, will be able to deliver sensory responses that mimic natural sensations of touch directly to the brain.

With the progress that the researchers have made with their animal experimentation, they hope to soon be able to test their devices during clinical trials with humans.

Studies Provide Fresh Insight into the Ancestry of Early Europeans

Posted October 11th, 2013 at 8:02 pm (UTC+0)
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A hunting group in the Stone Age (Victor Vasnetsov/Wikimedia Commons)

A hunting group in the Stone Age (Victor Vasnetsov/Wikimedia Commons)

Two recently released studies have shed new light on ancient Europeans.

Taking maternally-inherited mitochondrial DNA samples from bones and teeth of the skeletons of 364 people who lived about 5,000 years ago in what is now Central Europe, researchers in one study said that they were able to reconstruct the first detailed genetic history of modern-day Europeans.

The research that is allowing scientists to map the history of human migration is the result of a 7 – 8 year collaborative effort between the Australian Centre for Ancient DNA (ACAD), at the University of Adelaide, the Johannes Gutenberg University Mainz, the State Heritage Museum in Halle (Germany), and the National Geographic Society’s Genographic Project.

“This is the largest and most detailed genetic time series of Europe yet created, allowing us to establish a complete genetic chronology,” said the study’s joint-lead author Dr. Wolfgang Haak of ACAD. “Focusing on this small but highly important geographic region meant we could generate a gapless record, and directly observe genetic changes in ‘real-time’ from 7,500 to 3,500 years ago, from the earliest farmers to the early Bronze Age.”

The scientists said that their research revealed a pattern of genetic replacement in people who lived in central Europe over a period of several thousand years.  This indicates that some rather intricate changes went into producing today’s Europeans.

They also pointed out that noticeable changes in the genetic composition of those living in a region we now know as Germany was the result of at least four stages of migration and settlement of people who not only came from a long regarded path through the Near East, but also from Western and Eastern Europe.

“None of the dynamic changes we observed could have been inferred from modern-day genetic data alone, highlighting the potential power of combining ancient DNA studies with archaeology to reconstruct human evolutionary history,” said Haak.

Ancient Egyptian farmer plowing (Wikimedia Commons)

Ancient Egyptian farmer plowing (Wikimedia Commons)

The other study that examined the migration and settlement of Europe was led by scientists from Johannes Gutenberg University Mainz in Germany and the University College London in Great Britain.

This team of researchers, who also studied DNA taken from ancient human bones, found that native European “hunter-gatherers” – those who got their food from wild game and plants – lived side by side with immigrant farmers for about 2,000 years and were able to maintain their individual lifestyle much longer than was previously thought.

“It is commonly assumed that the Central European hunter-gatherers disappeared soon after the arrival of farmers”, said Dr. Ruth Bollongino, lead author of the study. “But our study shows that the descendants of Mesolithic Europeans maintained their hunter-gatherer way of life and lived in parallel with the immigrant farmers, for at least 2,000 years. The hunter-gathering lifestyle thus only died out in Central Europe around 5,000 years ago, much later than previously thought.”

Historians have said that farming or agriculture originated about 10,000 to 12,000 years ago in an area of the Near East known as the “fertile crescent” of Mesopotamia which included parts of today’s Iran, Iraq, Turkey, Syria, Lebanon, and Israel.  Descendants of those first farmers brought agriculture to Europe about 7,500 years ago.

“Until around 7,500 years ago all central Europeans were hunter-gatherers,” said Professor Mark Thomas, professor of evolutionary genetics at the University College London, and a co-author of the study. “They were the descendants of the first wave of our species to arrive in Europe, around 45,000 years ago. They survived the last Ice Age and the warming that started around 10,000 years ago. And now it seems they also survived the initial wave of farmers spreading across Europe from the southeast of the continent.”

While previous archaeological research has provided evidence of some forms of interaction between the native hunter-gatherers and their neighboring immigrant farmers, not much was known about the scope and length of their dealings with each other.

The newly released study showed that the farmers and hunter-gatherers did stay close to each other in proximity, maintained contact for thousands of years and even buried their dead in the same cave.

Scientists conducting palaeogenetic research in the ultra-clean laboratory at Mainz University (Thomas Hartmann)

Scientists conducting palaeogenetic research in the ultra-clean laboratory at Mainz University (Thomas Hartmann)

But the interaction between the two cultures apparently did have some limits.  The researcher’s investigation revealed that while hunter-gatherer women sometimes married into families in the farming communities, the opposite may not have been true since no genetic lines of farmer women have been found in hunter-gatherers.

“This pattern of marriage is known from many studies of human populations in the modern world,” explained Burger. “Farmer women regarded marrying into hunter-gatherer groups as social demotion.”

The scientists said that their study showed that individually neither the hunter-gatherers nor the farmers represent the common ancestry of today’s Europeans, but instead came from a mix of both populations.

First Evidence of Comet Strike Found

Posted October 9th, 2013 at 5:25 pm (UTC+0)
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An artist’s rendition of a comet exploding in Earth’s atmosphere above Egypt (Terry Bakker)

An artist’s rendition of a comet exploding in Earth’s atmosphere above Egypt (Terry Bakker)

A team of South African scientists writing in the journal ‘Earth and Planetary Science Letters’ said that they have found the first evidence of a comet striking Earth 28 million years ago.

“Comets always visit our skies – they’re these dirty snowballs of ice mixed with dust – but never before in history has material from a comet ever been found on Earth,” said David Block, a member of the research team and a professor of the University of the Witwatersrand.

The researchers said that the comet shot into Earth’s atmosphere and blew up above what is now known as Egypt with blast that wiped out every living thing in its path.

As the fireball exploded it created a super-hot shock wave that heated the sand on the surface to about 2,000 degrees Celsius.  The extreme heat and pressure formed a great quantity of yellow silica glass that was spread throughout a 6,000 square kilometer area of the Sahara that’s known as the Libyan Desert Glass strewn field.

Yellow silica glass from the Libyan Desert strewn field forms the body of a scarab in this brooch that belonged to Egyptian Pharaoh Tutankhamen (Wits University)

Yellow silica glass from the Libyan Desert strewn field forms the body of a scarab in this brooch that belonged to Egyptian Pharaoh Tutankhamun (Wits University)

A remarkable example of Libyan Desert Glass can be found on an ancient brooch of the Pharaoh Tutankhamun (King Tut) who ruled Egypt from 1332 BC to 1323 BC.  Egyptian jewelers polished and carved a piece of the yellow silica to form the body of a scarab that is prominently featured on the brooch.

The first evidence of a comet strike, said the scientists, came in the form of a mysterious 30 gram black pebble that had been found in 1996 by an Egyptian geologist who had been exploring the strewn field.

The pebble now called the Hypatia stone, was named in honor of Hypatia of Alexandria, the first well-known female mathematician, astronomer and philosopher.  The researchers said that the stone, which they described as being black, angular, shiny, incredibly hard and extremely fractured, is covered with microscopic diamonds that were created by the shock of the comet’s impact.

“Diamonds are produced from carbon bearing material. Normally they form deep in the earth, where the pressure is high, but you can also generate very high pressure with shock. Part of the comet impacted and the shock of the impact produced the diamonds,” said lead author Professor Jan Kramers of the University of Johannesburg.

After the South African team conducted a number of tests on the Hypatia stone, they concluded that the black pebble was not just an unusual type of meteorite but instead represented the very first known hand specimen of a comet nucleus.

Map of the Libyan Desert Glass strewn field and along with two possible impact structures in the Libyan Desert. (Gunnar Ries/Wikimedia Commons)

Map of the Libyan Desert Glass strewn field and along with two possible impact structures in the Libyan Desert. (Gunnar Ries/Wikimedia Commons)

The researchers said that comet material on Earth is incredibly rare.  The only other comet fragments that had been found were microscopic dust particles found in the upper atmosphere and in some carbon-rich dust found in Antarctic ice.

“NASA and ESA (European Space Agency) spend billions of dollars collecting a few micrograms of comet material and bringing it back to Earth, and now we’ve got a radical new approach of studying this material, without spending billions of dollars collecting it,” says Kramers.

The South African researchers said that an international collaborative research program has been formed to continue studies of the Hypatia stone.

“Comets contain the very secrets to unlocking the formation of our solar system and this discovery gives us an unprecedented opportunity to study comet material first hand,” said Block.

Curiosity Rover Finds Water on Mars

Posted September 27th, 2013 at 6:33 pm (UTC+0)
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This is the Sample Analysis at Mars (SAM) suite of instruments suite, prior to its installation on the Curiosity rover. (NASA Goddard)

The Sample Analysis at Mars (SAM) suite of instruments, prior to its installation on Curiosity. (NASA)

The first scoop of Martian soil analyzed by Curiosity Rover’s built-in laboratory has revealed a high amount of water in the soil, according to NASA.

“One of the most exciting results from this very first solid sample ingested by Curiosity is the high percentage of water in the soil,” said Curiosity researcher Laurie Leshin, of the Rensselaer Polytechnic Institute. “About 2 percent of the soil on the surface of Mars is made up of water, which is a great resource, and interesting scientifically.”

Researchers made their findings using Curiosity’s Sample Analysis at Mars (SAM) unit, which includes three sophisticated instruments: a gas chromotograph, mass spectrometer, and tunable laser spectrometer.

SAM allowed the scientists to identify a wide range of chemical compounds and to calculate the ratios of different isotopes of the sample’s key elements.

The same soil sample, when heated to 835 degrees Celsius, showed significant amounts of carbon dioxide, oxygen and various sulfur compounds.

The heated collection of Martian dust, dirt and fine soil, gathered by the rover’s scoop at a location called Rocknest, also revealed a compound containing chlorine and oxygen, which the scientists think is likely chlorate or perchlorate.

The Curiosity's scoop grabed a sample of Martian surface material and delivered it to it's built-in laboratory called SAM. This is a file photo of some trenches Curiosity dug in October 2012. (NASA/JPL-Caltech/MSSS)

Some of the trenches Curiosity’s scoop dug in Mars’ surface, Oct. 2012. (NASA)

Up until this finding, the scientists had thought those materials only existed in the high-latitude areas of Mars. By finding them at Curiosity’s current location near the equator of Mars, the researchers say that perhaps they could be found all over the planet.

Since they are formed in the presence of water, the carbonate materials that were found in their tested sample, according to the researchers, also provided clues to Martian water.

According to Leshin, the results of her team’s research shed light on the composition of the planet’s surface, while offering direction for future research.

“We now know there should be abundant, easily accessible water on Mars,” said Leshin. “When we send people, they could scoop up the soil anywhere on the surface, heat it just a bit, and obtain water.”

Scientists Learn More about Mysterious 3rd Van Allen Belt

Posted September 25th, 2013 at 7:49 pm (UTC+0)
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Computer animation showing the formation of the third Van Allen radiation belt. Green bar indicates time/day from 9/2/12 to 9/8/12 (UCLA)

Computer animation showing the formation of the third Van Allen radiation belt. Green bar indicates time/day from 9/2/12 to 9/8/12 (UCLA)

New research provides insight into the mysterious Van Allen radiation belts.

There are normally two of these giant bands of high-energy radiation encircling the Earth. However, researchers discovered a third and previously unknown radiation ring that only lasted for about a month back in September 2012.

Writing in a recent edition of Nature Physics, scientists from UCLA College of Letters and Science  found the third ring was composed of extremely energetic particles, known as ultra-relativistic electrons, which can move at speeds close to the speed of light.

“The Van Allen Probes observations challenged our current views on the physics of the radiation belts,” said study co-author Yuri Shprits, a space scientist at UCLA. “In the past, we made estimates and thought they looked reasonable. Now we know we need to understand each storm in much more detail, creating global models that can reconstruct what’s happening at every level.”

Armed with data from the Van Allen Probes, two robotic spacecraft that are on two-year mission to study radiation belts, the researchers were able to create new computer models which help explain the extraordinary behavior of that transient third ring.

“The ultra-relativistic electrons of the third ring have so much energy that they are driven by very different physical processes,” said Shprits. “Incorporating that information not only explains the unusual observation of the long-lived narrow middle ring, it opens up a new area of research for the ultra-relativistic particles.”

Artist rendering of the twin Van Allen Probes in Earth orbit (NASA)

Artist rendering of the twin Van Allen Probes in Earth orbit (NASA)

The Van Allen belts were the first major discovery of the Space Age when they were first observed by NASA’s Explorer One spacecraft in 1958.

Scientists were able to determine that the belts, which receive their high-energy particles from solar wind and from cosmic rays, expand and contract, as well as change shape, as solar disturbances make their way toward Earth.

These bands of highly-charged energy are kept in place some 1,600 to 60,000 kilometers above the Earth’s surface by our planet’s magnetic fields.

The researchers said better understanding of the radiation belts surrounding Earth might someday help scientists better predict space weather that impacts our planet. Flare ups in space weather can cause problems with orbiting satellites, which in turn could impact communications and GPS systems.

Study: Sudden Explosion of Cambrian Period Animal Life Caused by a ‘Cascade of Events’

Posted September 19th, 2013 at 5:59 pm (UTC+0)
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Fossil of a Trilobite - Cheirurus ingricus - from the early Cambrian period (Tim Evanson/Creative Commons via Flickr)

Fossil of a Trilobite – Cheirurus ingricus – from the early Cambrian period (Tim Evanson/Creative Commons via Flickr)

Last week we told you about an Australian study that suggested that the evolution of life during the Cambrian Explosion took place at five times the rate it occurs today.

Now, another group of scientists from Britain, in their newly published study, weigh in on the “Big Bang of Life.”  They propose that the explosion of animal life on Earth that took place some 520 to 540 million years ago was not the result of just one single principal cause, but rather from a combination of interwoven factors.

The Cambrian Explosion, the researchers said, was a major evolutionary event that led to a wide range of biological innovation, which included the beginning of modern ecosystems, a rapid increase in animal diversity, the origin of skeletal creatures and the first appearance of specialist modes of life such as burrowing and swimming.

Animals that made their first appearances on Earth during the Cambrian explosion, according to the researchers, included vertebrates such as the distant ancestors of modern fish, reptiles, birds and mammals.

The British researchers suggested that in order to determine the reasons behind the Cambrian Explosion, scientists need to take a more ‘holistic approach’ that encompass a range of factors.

A number of odd looking lifeforms, like the Anomalocaris, pictured in this model, came out of the Cambrian explosion.  Model on display at the National Dinosaur Museum, Canberra, Australia. (Phonart via Wikimedia Commons)

A number of odd looking lifeforms, like the Anomalocaris, pictured in this model, came out of the Cambrian explosion. Model on display at the National Dinosaur Museum, Canberra, Australia. (Phonart via Wikimedia Commons)

“This is a period of time that has attracted a lot of attention because it is when animals appear very abruptly in the fossil record, and in great diversity. Out of this event came nearly all of the major groups of animals that we recognize today,” said Paul Smith, lead author of the study and director of the Oxford University Museum of Natural History.

“Because it is such a major biological event, it has attracted much opinion and speculation about its cause,” Smith said.

Over the years there have been a number of theories about the Cambrian Explosion.  The researchers said that those concepts, which fall into three main categories – geological, geochemical and biological — are separate and exclusive processes that also suggest a single cause of the explosion.

The researchers said that they consider the Big Bang of Life was the result of a “cascade of events,” more of a complex interaction of those biological, geochemical and geological processes that were suggested in those individual theories.

“It would be naive to think that any one cause ignited this phenomenal explosion of animal life. Rather, a chain reaction involving a number of biological and geological drivers kicked into gear, escalating the planet’s diversity during a relatively short interval of deep time,” said David Harper, co-author of the study and a professor of paleontology at Durham University.

Some consider the long extinct Haikouichthys (artist rendering), that emerged from the Cambrian explosion, one of the earliest fishes on Earth (Talifero via Wikimedia Commons)

Some consider the long extinct Haikouichthys (artist rendering), that emerged from the Cambrian explosion, one of the earliest fishes on Earth (Talifero via Wikimedia Commons)

The British researchers propose that the causes behind the explosion of animal life probably began with an early Cambrian rise in sea level.

This sea level rise, they said, generated a large increase in the area of habitable seafloor, which in turn drove an increase in animal diversity.

The team of scientists, led by Smith and Harper, wrote their study after working for four years from data that was gathered from a site that faced the Arctic Ocean in northernmost Greenland.

The team was attracted to the site, which they said was difficult to reach, because of the high quality of its fossil material and the insights it provided.

The research team’s findings can be found in the latest edition of the journal Science.

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