Birds May Have Flown Like Four-Winged Kittyhawk

The world's first birds all had four wings -- not two -- and flew with a similar construction to the Wright Brothers' Kitty Hawk plane, contends new research led by the renowned dinosaur and early avian hunter Xing Xu.

Xu, a paleontologist at the Chinese Academy of Sciences, and his team suggest this perhaps might be the simplest form of flight, as even the Wright brothers' first experiments with flight were done with a biplane in 1903.

As for how this system in birds evolved, Xu told Discovery News, "The first birds descended from four-winged dinosaurs, which are not necessarily gliders in the strictest sense."

One such dinosaur might have been Microraptor, a non-avian dino that had feathers on both its arms and legs. Paleontologists believe it could fly.

The researchers studied well-preserved fossils of 11 birds from at least four diverse groups dating from about 150 to 100 million years ago. All of the birds were found in the Jehol formation in Liaoning, northeastern China.

The ancient birds were found to have clumps of stiff leg feathers that resemble wings. Xu and his colleagues believe these were, in fact, wings, according to the study, published in the journal Science. He said they "either provided lift, or created drag, or enhanced maneuverability or a combination of all of these functions."

Xu explained that the earliest birds were primarily arboreal, so they would have flown from trees instead of taking off from the ground or water, as today’s birds often do, depending on the species.

This could help to explain why birds lost the extra “wing” leg feathers over time, evolving the two-winged anatomy of today.

Xu said that this loss happened “primarily because of the evolution of two different locomotion systems in birds -- arm wings for flight and legs for walking and running.”

He added that the shift from a tree habitat to ground and water ones would have also favored the loss of the leg feathers.

Sankar Chatterjee, a paleontologist at Texas Tech University, told Michael Balter of Science that the new study makes it clear that "the four-wing form was exhibited not just by Microraptor, but also retained …in successive lineages of early birds."

Kevin Padian, a paleontologist at the University of California at Berkeley, also agrees that the research establishes that leg feathers were widely distributed, but he remains skeptical that the leg feathers were, in fact, used for flight.

Read more at Discovery News

Physicists Hunt Weird Antimatter Within Earth

Scientists have tentatively identified several particles lurking deep inside the Earth's mantle that could reveal how much heat the planet produces and confirm that the Earth formed from materials from the sun.

The wacky particles are called geoneutrinos, or the antimatter partners of neutrinos (exotic fundamental particles that can pass right through Earth), that form deep within the Earth's mantle. Every matter particle has an antimatter partner particle that has an opposite charge, and when the two meet they annihilate each other. The findings were detailed described March 11 in the preprint journal arXiv.org.

Geoneutrinos aren't the only particles scientists are hoping to find inside Earth. An experiment using the Earth as a source of electrons recently narrowed down the search for a new force-bearing particle, possibly the so-called unparticle, placing tighter limits on the force it carries.

Giant Engine

When Earth formed, the radioactive elements thorium and uranium were distributed in Earth's interior at different concentrations within the crust (the planet's outer layer) and mantle. As these elements within the mantle radioactively decay, they give off heat and also form subatomic particles known as geoneutrinos, said study co-author Aldo Ianni, a physicist at the Gran Sasso National Laboratory in Italy.

The heat formed from this decay is the engine that drives the motion of the viscous, oozing material that forms the Earth's mantle. That, in turn can shift the tectonic plates, causing earthquakes. Whereas researchers have models to predict how much heat is generated inside the Earth, measuring it has proved tricky.

That's partly because mantle lies miles beneath the Earth's surface, so "if you want to understand how much heat is produced by these radioactive elements, the only way today to understand how much is this so-called radiogenic heat is through the geoneutrinos," Ianni said.

Tiny Particles

To do so, researchers at the Gran Sasso underground laboratory, which is nearly a mile below a mountain in Italy, looked for signals in a vast pool of oil-based liquid that scintillates, or produces flashes of light when particles such as protons pass through it. When geoneutrinos pass through the scintillating liquid they bump into protons and emit a positron and then a neutron, creating a distinctive signal, Ianni told LiveScience.

Many of the particles they initially identified actually came from nuclear reactors from power plants. But by measuring the energy levels of the neutrinos, they could isolate the 30 percent that came from the Earth's mantle, Ianni said.

The geoneutrinos are created from the decay of radioactive thorium and uranium in a reaction that gives off a known amount of heat. As a result, how frequently the researchers find the particles can reveal the quantity of the radioactive elements lurking in Earth's mantle, and in turn how much heat they generate. That can help scientists refine their knowledge of plate tectonics, Ianni said.

Read more at Discovery News

Confirmed! Newfound Particle Is the Higgs

A newfound particle discovered at the world's largest atom smasher last year is, indeed, the Higgs boson, the particle thought to give other matter its mass, scientists reported today (March 14) at the annual Rencontres de Moriond conference in Italy.

Physicists announced on July 4, 2012, that, with more than 99 percent certainty, they had found a new elementary particle weighing about 126 times the mass of the proton that was likely the long-sought Higgs boson. The Higgs is sometimes referred to as the "God particle," to the chagrin of many scientists, who prefer its official name.

But the two experiments, CMS and ATLAS, hadn't collected enough data to say the particle was, for sure, the Higgs boson, the last undiscovered piece of the puzzle predicted by the Standard Model, the reigning theory of particle physics.

Now, after collecting two and a half times more data inside the Large Hadron Collider (LHC) — where protons zip at near light-speed around the 17-mile-long (27 kilometer) underground ring beneath Switzerland and France — physicists say the particle is the Higgs.

"The preliminary results with the full 2012 data set are magnificent and to me it is clear that we are dealing with a Higgs boson though we still have a long way to go to know what kind of Higgs boson it is," said CMS spokesperson Joe Incandela in a statement.

Dave Charlton, ATLAS spokesperson agreed, the new results "point to the new particle having the spin-parity of a Higgs boson as in the Standard Model," referring to a quantum property of elementary particles.

To confirm the particle as the Higgs boson, physicists needed to collect tons of data that would reveal its quantum properties as well as how it interacted with other particles. For instance, a Higgs particle should have no spin and its parity, or the measure of how its mirror image behaves, should be positive, both of which were supported by data from the ATLAS and CMS experiments.

Even so, the scientists are not sure whether this Higgs boson is the one predicted by the Standard Model or perhaps the lightest of several bosons predicted to exist by other theories.

Seeing how this particle decays into other particles could let physicists know whether this Higgs is the "plain vanilla" Standard Model Higgs. Detecting a Higgs boson is rare, with just one observed for every 1 trillion proton-proton collisions. As such, the LHC physicists say they need much more data to understand all of the ways in which the Higgs decays.

From what is known about the particle now, physicists have said the Higgs boson may spell the universe's doom in the very far future. That's because the mass of the Higgs boson is a critical part of a calculation that portends the future of space and time. Its mass of 126 times the mass of the proton is just about what would be needed to create a fundamentally unstable universe that would lead to a cataclysm billions of years from now.

Read more at Discovery News

Life Under a Tiny, Red, Angry Sun

Recent estimates are that 6 percent of red dwarf stars in our galaxy should have Earth-sized worlds. Six percent! That means that our galaxy could potentially be overflowing with terrestrial planets.

Six percent may not sound like a lot, but red dwarfs are astonishingly populous. Approximately 75 percent of all stars are red dwarfs. Assuming that there are around 300 billion stars in the Milky Way, that means there should be over 13.5 billion exo-Earths orbiting the tiny red suns strewn across our galaxy.

Red dwarfs have always been a source of controversy for planet hunters and astrobiologists. They’ve been frequently ignored in exoplanet searches, largely because they’re noisy little beasts that makes finding anything out about them rather taxing. That is, until Courtney Dressing and her colleagues looked at data from Kepler in an attempt to settle the arguments. As it happens, their study found that around 60 percent of red dwarfs should have planets smaller than Neptune, which means — as some astronomers have long suspected — these tiny stars are likely to be good hunting grounds for exoplanets.

So what exactly is the deal with red dwarfs? Are they good homes for life or not?

One Angry Dwarf

Well, a big problem with red dwarfs is that many of them are ill-tempered little things; prone to violent and unpredictable outbursts.

These little stars are fully convective, meaning that material circulates all the way from the core up to their surfaces, unlike the sun that only has convection currents in its exterior layers. This gives rise to immense magnetic fields, which are responsible for Goliath temper tantrums.

Many red dwarfs are flare stars, occasionally increasing significantly in brightness. Flares seen on these little red stars can put the solar flares we see on the sun to shame. They’re also correspondingly more lethal, brightening the star’s electromagnetic output from radio waves all the way up to x rays!

Paradoxically, the same magnetic activity powering these flares also causes dramatic starspot activity — just like sunspots, only much much more so.

Because a red dwarf is so much smaller than the sun, and its magnetic fields are so much stronger, starspots can cause the brightness of these grouchy little stars to drop by up to 40 percent. I hasten to add that not all red dwarfs are quite so volatile. But many of them are.

The other problem with life under a red sun is that red dwarf stars are cool. And I don’t mean cool like Neil deGrasse Tyson, I mean literally cool. The surface temperature of an average red dwarf is around 2000-4000 Kelvin. Compared with the sun’s surface temperature of nearly 6000 Kelvin, that’s only lukewarm. At this lower temperature, most red dwarfs struggle to put out even 1 percent the luminosity of the sun.

This means that habitable planets around red dwarfs have to lie in very tight orbits to stay warm. Practically hugging their tiny red suns for warmth, they’re very much in danger from the titanic flares that these stars can belch out.

Sunny Side Up

This isn’t to say, however, that life isn’t possible under a red sun — but it would have to be very different to what we’re familiar with.

For one thing, the habitable zone around a red dwarf is so close that any of these watery Earth-like worlds would surely be tidally locked. One side would constantly be facing the warmth of their parent star, while the other side would be freezing cold and in constant night.

This may not be as bad as it sounds. Some have hypothesized that the star-facing side of such planets may have a perpetual storm, and the night side would likely be frozen solid. In between the extremes though, such planets may have a belt of warm and potentially life sustaining surface.

Geothermal energy locked in these planets could help to stabilize their temperatures, oceans would certainly help to transport warmth around a planet. A dense Earth-like atmosphere would help too, and even more of that precious red sunlight could be trapped by greenhouse gasses which might accumulate in that atmosphere. Red dwarf stars don’t emit a lot of ultraviolet light.

With less ultraviolet to break molecules apart, potent greenhouse gasses like methane could accumulate and act like planetary blankets. The chemistry of planets around red dwarfs stars is likely to be very different to anything we see in our own solar system.

A Leisurely Life

Red dwarfs have one more trick up their sleeves. They’re very very long lived. So long lived, in fact, that no red dwarf has ever died in our universe, because the universe isn’t old enough yet!

The sun formed roughly 4.6 billion years, and will keep on burning just as it is today for another 5.4 billion years. By contrast, a red dwarf born at the same time would barely be a teenager. For example, Barnard’s star — a friendly neighborhood red dwarf, just under 6 light years away — has a life expectancy of 2.5 trillion years. Over 200 times that of the sun. No one even knows if a planet can support life for that long!

While we know that life evolved here on Earth quite soon after our planet formed, we have no idea how long it would normally take for this to happen. If it’s even remotely possible for the same thing to happen on a red dwarf planet, it would have literally all the time in the universe in which to do so!

Whether or not life exists is still an unanswered question, and one that we won’t be able to answer until our telescopes are powerful enough to actually take a detailed look at planets around red dwarf stars. That said, with 13.5 billion planets to choose from, probability may well be on the side of the astrobiologists!

Read more at Discovery News

Shape-Shifting Jesus Described in Ancient Egyptian Text

A newly deciphered Egyptian text, dating back almost 1,200 years, tells part of the crucifixion story of Jesus with apocryphal plot twists, some of which have never been seen before.

Written in the Coptic language, the ancient text tells of Pontius Pilate, the judge who authorized Jesus' crucifixion, having dinner with Jesus before his crucifixion and offering to sacrifice his own son in the place of Jesus. It also explains why Judas used a kiss, specifically, to betray Jesus — because Jesus had the ability to change shape, according to the text  — and it puts the day of the arrest of Jesus on Tuesday evening rather than Thursday evening, something that contravenes the Easter timeline.

The discovery of the text doesn't mean these events happened, but rather that some people living at the time appear to have believed in them, said Roelof van den Broek, of Utrecht University in the Netherlands, who published the translation in the book "Pseudo-Cyril of Jerusalem on the Life and the Passion of Christ"(Brill, 2013).

Copies of the text are found in two manuscripts, one in the Morgan Library and Museum in New York City and the other at the Museum of the University of Pennsylvania. Most of the translation comes from the New York text, because the relevant text in the Pennsylvania manuscript is mostly illegible.

Pontius Pilate has dinner with Jesus

While apocryphal stories about Pilate are known from ancient times, van den Broek wrote in an email to LiveScience that he has never seen this one before, with Pilate offering to sacrifice his own son in the place of Jesus.

"Without further ado, Pilate prepared a table and he ate with Jesus on the fifth day of the week. And Jesus blessed Pilate and his whole house," reads part of the text in translation. Pilate later tells Jesus, "well then, behold, the night has come, rise and withdraw, and when the morning comes and they accuse me because of you, I shall give them the only son I have so that they can kill him in your place."

In the text, Jesus comforts him, saying, "Oh Pilate, you have been deemed worthy of a great grace because you have shown a good disposition to me." Jesus also showed Pilate that he can escape if he chose to. "Pilate, then, looked at Jesus and, behold, he became incorporeal: He did not see him for a long time ..." the text read.

Pilate and his wife both have visions that night that show an eagle (representing Jesus) being killed.

In the Coptic and Ethiopian churches, Pilate is regarded as a saint, which explains the sympathetic portrayal in the text, van den Broek writes.

The reason for Judas using a kiss

In the canonical bible the apostle Judas betrays Jesus in exchange for money by using a kiss to identify him leading to Jesus' arrest. This apocryphal tale explains that the reason Judas used a kiss, specifically, is because Jesus had the ability to change shape.

"Then the Jews said to Judas: How shall we arrest him (Jesus), for he does not have a single shape but his appearance changes. Sometimes he is ruddy, sometimes he is white, sometimes he is red, sometimes he is wheat coloured, sometimes he is pallid like ascetics, sometimes he is a youth, sometimes an old man ..." This leads Judas to suggest using a kiss as a means to identify him. If Judas had given the arresters a description of Jesus he could have changed shape. By kissing Jesus Judas tells the people exactly who he is.

This understanding of Judas' kiss goes way back. "This explanation of Judas' kiss is first found in Origen (a theologian who lived A.D. 185-254)," van den Broek writes. In his work, Contra Celsum the ancient writerOrigen, stated that "to those who saw him he did not appear alike to all."

St. Cyril impersonation

The text is written in the name of St. Cyril of Jerusalem who lived during the fourth century. In the story Cyril tells the Easter story as part of a homily (a type of sermon).  A number of texts in ancient times claim to be homilies by St. Cyril and they were probably not given by the saint in real life, van den Broek explained in his book.

Near the beginning of the text, Cyril, or the person writing in his name, claims that a book has been found in Jerusalem showing the writings of the apostles on the life and crucifixion of Jesus. "Listen to me, oh my honored children, and let me tell you something of what we found written in the house of Mary ..." reads part of the text.

Again, it's unlikely that such a book was found in real life. Van den Broek said that a claim like this would have been used by the writer "to enhance the credibility of the peculiar views and uncanonical facts he is about to present by ascribing them to an apostolic source," adding that examples of this plot device can be found "frequently" in Coptic literature.

Arrest on Tuesday

Van den Broek says that he is surprised that the writer of the text moved the date of Jesus' Last Supper, with the apostles, and arrest to Tuesday. In fact, in this text, Jesus' actual Last Supper appears to be with Pontius Pilate. In between his arrest and supper with Pilate, he is brought before Caiaphas and Herod.

In the canonical texts, the last supper and arrest of Jesus happens on Thursday evening and present-day Christians mark this event with Maundy Thursday services. It "remains remarkable that Pseudo-Cyril relates the story of Jesus' arrest on Tuesday evening as if the canonical story about his arrest on Thursday evening (which was commemorated each year in the services of Holy Week) did not exist!" writes van den Broek in the email.

A gift to a monastery ... and then to New York

About 1,200 years ago the New York text was in the library of the Monastery of St. Michael in the Egyptian desert near present-day al-Hamuli in the western part of the Faiyum. The text says, in translation, that it was a gift from "archpriest Father Paul," who, "has provided for this book by his own labors."

The monastery appears to have ceased operations around the early 10th century, and the text was rediscovered in the spring of 1910. In December 1911, it was purchased, along with other texts, by American financier J.P. Morgan. His collections would later be given to the public and are part of the present-day Morgan Library and Museum in New York City. The manuscript is currently displayed as part of the museum's exhibition "Treasures from the Vault" running through May 5.

Read more at Discovery News

Neanderthals Lacked Social Skills

For ages, anthropologists have puzzled over Neanderthal and human brains, since they were the same size. If each species had comparable brainpower, why did humans dominate?

A comparison of Neanderthal and human brains has revealed it was a matter of allocation: Neanderthal brains focused more on vision and movement, leaving less room for cognition related to social networking.

According to the study, published in the journal Proceedings of the Royal Society B, bigger eyed and larger bodied Neanderthals required more brain space devoted to the visual system and basic body functions, leaving less area for what co-author Robin Dunbar called "the smart part."

He explained to Discovery News that this is "the part that is doing the creative thinking."

Dunbar, a professor of evolutionary psychology at the University of Oxford, and colleagues Eiluned Pearce and Chris Stringer compared the skulls of 32 anatomically modern humans and 13 Neanderthals. The skulls date to 27,000 to 75,000 years ago. The researchers noticed that Neanderthals had significantly larger eye sockets.

The researchers next used the known relationship between the height of the eye socket and the size of visual brain areas in living primates to estimate how much of each brain was dedicated to visual processing. Once differences in body and visual system size were taken into account, the researchers could then compare how much of the brain was left over for other types of cognition.

It's clear that environmental differences affected the evolution of each species. The common ancestor of Neanderthals and Homo sapiens was Homo heidelbergensis. It had a bulkier body, as for Neanderthals, but did not possess enlarged eyes.

"The large eyes (of Neanderthals) are purely an adaptation to low light levels, and long dark nights at higher latitudes outside the tropics," Dunbar said.

Neanderthals also tended to be shorter than humans, which again was an adaptation to colder climates since this reduces heat loss through the extremities. Modern Eskimos exhibit some of this adaptation.

Neanderthals in Europe also "developed a very confrontational and dangerous style of hunting, and were very dependent on a heavy meat diet," Dunbar shared. "Modern humans (in Africa) developed the bow and arrow, as well as spear throwers, which allowed hunting at arms’ length and often focused on smaller prey."

As for what happened to the Neanderthals, some researchers believe that they were simply absorbed into the modern human population. There is evidence that, as numerous humans migrated north into Europe, they interbred with Neanderthals.

Another theory, supported by this new study, is that Neanderthals went extinct because they were less capable of forming larger social networks. Pearce theorized that "smaller social groups might have made Neanderthals less able to cope with the difficulties of their harsh Eurasian environments because they would have had fewer friends to help them out in times of need."

She continued, "Overall, differences in brain organization and social cognition may go a long way towards explaining why Neanderthals went extinct whereas modern humans survived."

Dunbar further thinks that new diseases brought in by humans could have hurt Neanderthals. He said, "It was clear that, by the end, they were struggling to maintain a foothold in Ice Age Europe, having been squeezed down into the southern appendages of Europe (in places like Spain and Italy)."

Clive Gamble, an expert on the archaeology of human origins and a professor at Southampton University praised the new work, saying, "This paper cracks a big problem in human evolution. Neanderthals had brains as big as ours, yet did not regularly produce the sorts of cultural stuff- art, ornamentation and complicated tools -- that we take for granted…Brains got bigger, but in different ways."

Read more at Discovery News

What Is Life, Anyway?

NASA officials announced March 12 that ancient Mars could have supported primitive life. But this begs the question: What exactly constitutes life?

Merriam-Webster.com defines life as "an organismic state characterized by capacity for metabolism, growth, reaction to stimuli and reproduction." But there's no single satisfactory definition of life.

"I think it is a mistake to try to define life, because we have only one example of life, familiar life on Earth, and we have reason to believe that this example may be unrepresentative of life in general," Carol Cleland, a philosopher of science at the University of Colorado, Boulder, told LiveScience in an email.

Defining life

Aristotle made the first attempt at a definition, describing life as something that grows, maintains itself and reproduces. But this definition would exclude mules, which are sterile, while including things like fire.

Calling life something that has a metabolism, the ability to take in energy to grow or move and excrete waste, is no good either; cars do this, for example.

In 1944, the physicist Erwin Schrödinger gave life a definition based on the second law of thermodynamics, which states that the entropy, or disorder, of a closed system increases over time. Schrödinger defined life as something that decreases or maintains its entropy. Yet this definition fails because it includes crystals, which resist entropy by forming highly structured lattices.

Trying to define life by its qualities is the wrong approach, Cleland said. As an example, she cites scientists' early attempts to define water in terms of properties like being wet, transparent and a good solvent. "We didn't 'define' water as H2O, but rather discovered, in the context of molecular theory, that it is a chemical substance composed mostly of H2O molecules," Cleland said.

Life on Earth is typically divided into two main groups: the cellular life forms, which include archaea, bacteria and eukarya (all the plants and animals), and non-cellular life forms, like viruses. Whether viruses, which can replicate only inside the cells of a host organism, count as "life" is debated.

Life in the universe

Finding an airtight definition for life may not be so important, astrobiologist Chris McKay of NASA's Ames Research Center in California wrote in an email to LiveScience. It's "much better to have an idea of what life is built of," McKay said. "Life is built of complex, organic molecules."

Characterizing life is vital for identifying it elsewhere in the universe, a possibility now beyond the realm of science fiction. McKay said that if life exists somewhere else, it would be a material system evolving through reproduction, mutation and natural selection.

Read more at Discovery News

Monster Starbursts Seen by New Radio Telescope

With new instruments coming online, the most distant (and youngest) regions of our universe are finally being explored in depth.

This week, the Atacama Large Millimeter/Submillimeter Array, or ALMA, is being dedicated, and they’re celebrating with an amazing new study of some of the most distant prolifically star-forming galaxies.

The millimeter and submillimeter wave bands can be thought of as very short wavelength radio astronomy, or very long wavelength infrared. For decades, it’s been a hard region of the electromagnetic spectrum to probe since water vapor in our atmosphere causes a lot of absorption and distortion, and the challenges that go into the technology are non-trivial.

But after 30 years of plotting and planning, an international collaboration has succeeded in creating a sensitive instrument at a high dry mountain site that can fully open up this part of the universe.

It turns out, thanks to a lucky coincidence of physics, that the millimeter band is a great place to study distant, star-forming galaxies. You can see galaxies over a wide range of redshifts, or distances, in this band with little bias. That is, you just don’t see the brightest sources from further away; you get the whole history of galaxy formation in one go. Well, theoretically, at least. Previously existing millimeter wave telescopes were not very sensitive, and so only could see a small part of the population.

Now ALMA is coming online, and a study led by Joaquin Vieira using just 16 of the array’s planned 66 antennas have already doubled the number of star-forming galaxies seen at redshifts greater than 4, or from the first 1.5 billion years of the universe’s history. Also, each observation took only 2 minutes to create images that would have taken older telescopes hours to produce, if they even could.

So, technologically, this is pretty mind-blowing and demonstrates the capability of ALMA, even in its earliest stages. Scientifically, this is a boon for astronomers wanting to understand galaxy formation in the early universe, as this is one of the most important research questions of the day.

These galaxies are all gravitationally lensed by some foreground object, such as an elliptical galaxy, and that helps us to see the furthest objects.

In total, 47 galaxies were imaged, and spectra were collected from 26 of these. A spectrum is taken when the light from the object is separated by wavelength, not unlike a prism making a rainbow out of visible light.

ALMA’s scientific prowess stems in part from very fine spectral resolution, allowing for detailed studies of emission lines from molecular clouds. The other part of its strength, the incredible sensitivity, allows astronomers to see much fainter lines than ever before.

The spectra collected from these galaxies highlight an important analysis, the exact determination of redshift, or distance, to distant galaxies.

The most accurate way to determine redshift is to measure several spectra lines and how much they have been shifted to longer wavelengths by the expansion of the universe over great distances. However, astronomers often rely on more indirect techniques for very distant objects when no lines can be seen. Also, optical and infrared telescopes cannot easily survey these star-forming distant galaxies because they are obscured by their own dust. The millimeter and submillimeter regime is the way to go to collect precise redshifts of this population.

Read more at Discovery News

New Hope for Reversing the Effects of Spinal Cord Injury

Walking is the obvious goal for individuals who have a chronic spinal cord injury, but it is not the only one. Regaining sensation and continence control also are important goals that can positively impact an individual's quality of life. New hope for reversing the effects of spinal cord injury may be found in a combination of stem cell therapy and physical therapy as reported in Cell Transplantation by scientists at the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School.

"Our phase one/two clinical trial had one goal: to give patients who have no other treatment options some hope," said Hatem E. Sabaawy, MD, PhD, an assistant professor of medicine in the molecular and regenerative medicine program at Robert Wood Johnson Medical School. "Early findings have concluded that we have met our goal and can improve the quality of life for individuals with spinal cord injuries by providing a safe treatment that restores some neurological function."

Dr. Sabaawy led a clinical trial that included 70 patients who had cervical or thoracic spinal cord injuries and were previously treated for at least six months without response. The patients were randomized into two groups, both of which were given physical therapy treatment. One of the groups also received stem cells derived from their own bone marrow injected near the injury site. Using the American Spinal Injury Association Impairment (AIS) Scale, patients received neurological and physical evaluations monthly for 18 months to determine if sensory and motor functions improved.

"Of primary importance, there was a notable absence of side effects in patients treated with stem cells during the course of our investigation," added Dr. Sabaawy, who also is a resident member of The Cancer Institute of New Jersey at Robert Wood Johnson Medical School.

None of the patients in the control group who received only physical therapy showed any improvement in sensory or motor function during the same time frame. Although the scale of injuries differed, all patients who were treated with a combination of bone-marrow derived stem cells and physical therapy responded to tactile and sensory stimuli as early as 4 weeks into the study. After 12 weeks, they experienced improvements in sensation and muscle strength, which was associated with enhanced potency and improved bladder and bowel control that eventually allowed patients to live catheter-free. Patients who showed improvement based on the AIS scale also were able to sit up and turn in their beds.

"Since the emergence of stem cells as a potential therapy for spinal cord injury, scientists have diligently sought the best application for using their regenerating properties to improve a patient's mobility," said Joseph R. Bertino, MD, University Professor of medicine and pharmacology, interim director, Stem Cell Institute of New Jersey and chief scientific officer at The Cancer Institute of New Jersey. "Dr. Sabaawy's discovery that treatment is more successful when stem cell therapy is combined with physical therapy could provide a remarkable, and hopefully sustainable, improvement in the overall quality of life for patients with spinal cord injury."

At the end of 18 months, 23 of the 50 patients who received both physical therapy and stem cell therapy showed a significant improvement of at least 10 points on the AIS scale. Several were able to walk with assistance. In addition, more gains were made in motor skill control by patients with thoracic spinal cord injuries, suggesting that patients with thoracic spinal cord injuries may respond better to the combined treatment.

Dr. Sabaawy however cautioned that more studies are needed with a larger number of patients to test different cell dose levels and intervals at which stem cell therapy should be delivered.

Read more at Science Daily

Earth-Sized Planets in Habitable Zones Are More Common Than Previously Thought

The number of potentially habitable planets is greater than previously thought, according to a new analysis by a Penn State researcher, and some of those planets are likely lurking around nearby stars.

"We now estimate that if we were to look at 10 of the nearest small stars we would find about four potentially habitable planets, give or take," said Ravi Kopparapu, a post-doctoral researcher in geosciences. "That is a conservative estimate," he added. "There could be more."

Kopparapu detailed his findings in a paper accepted for publication in Astrophysical Journal Letters. In it, he recalculated the commonness of Earth-sized planets in the habitable zones of low-mass stars, also known as cool stars or M-dwarfs.

Scientists focus on M-dwarfs for several reasons, he explained. The orbit of planets around M-dwarfs is very short, which allows scientists to gather data on a greater number of orbits in a shorter period of time than can be gathered on Sun-like stars, which have larger habitable zones. M-dwarfs are also more common than stars like Earth's Sun, which means more of them can be observed.

According to his findings, "The average distance to the nearest potentially habitable planet is about seven light years. That is about half the distance of previous estimates," Kopparapu said. "There are about eight cool stars within 10 light-years, so conservatively, we should expect to find about three Earth-size planets in the habitable zones."

The work follows up on a recent study by researchers at the Harvard-Smithsonian Center for Astrophysics which analyzed 3,987 M-dwarf stars to calculate the number of Earth-sized planet candidates in cool stars' habitable zones -- a region around a star where rocky planets are capable of sustaining liquid water and therefore life. That study used habitable zone limits calculated in 1993 by Jim Kasting, now an Evan Pugh Professor in Penn State's Department of Geosciences. Kopparapu noticed that its findings, based on data from NASA's Kepler satellite, didn't reflect the most recent estimates for determining whether planets fall within a habitable zone.

These newer estimates are based on an updated model developed by Kopparapu and collaborators, using information on water and carbon dioxide absorption that was not available in 1993. Kopparapu applied those findings to the Harvard team's study, using the same calculation method, and found that there are additional planets in the newly determined habitable zones.

Read more at Science Daily