If someone told you they’d created a material that looks and feels like bone on an ink-jet printer, you’d probably laugh.
But researchers at Washington State University have done just that. The researchers used a 3D printer to create a bone-like material and structure that they say can be used in applications such as orthopedic procedures, dental work, and as a way to deliver medicine for treating osteoporosis. When paired with actual bone, this newly produced material acts as a scaffold for new bone to grow on and, ultimately, dissolves with no apparent ill effects.
Reporting in the journal Dental Materials, the researchers say they’ve been successful with in-vitro tests (inside a test tube) and that they’re already seeing promising results with in-vivo (inside a living body) tests on rats and rabbits.
They think it’s possible doctors will be able to custom order replacement bone tissue in a few years.
The printer that produces this bone-like material works by having an ink-jet spray a plastic binder over a bed of powder in layers. Each layer is about half the width of a human hair. Following a computer’s directions, it creates a channeled cylinder the size of a pencil eraser.
And, after just a week in a medium with immature human bone cells, the scaffold produced by the manufactured material supported a network of new bone cells.
A raven (Corvus corax) (Photo: Accipiter (R. Altenkamp, Berlin))
Along with our voices, humans also communicate with each other via non-vocal signals such as gestures. When we want to attract someone’s attention to something, it’s not uncommon for us to point or hold up an object we’d like someone to look at.
The only other creatures, scientists say, that have been observed using these visual signals, called deictic gestures, are our closest genetic relatives, the great apes.
Now, two researchers say they have evidence that ravens also use various attention-grabbing gestures to test the interest of a potential partner or to strengthen an already existing relationship.
The researchers, Simone Pika und Thomas Bugnyar, noticed ravens use their beaks as we humans would use our hands to show and offer objects such as moss, stones and twigs. They found the ravens predominantly aimed these gestures at their partners of the opposite sex, which resulted in frequent recognition between the signaler and recipient.
After this exchange of gestures, the ravens interacted with each other, for example, by example billing or joint manipulation of the object.
Eradicating polio might prove more challenging than thought
Young girl in Conakry, Guinea getting her polio vaccine. (Photo: Julien Harneis on Flickr)
While world health officials have largely reached their goal of eliminating polio worldwide, actually declaring the disease completely eradicated may be far more difficult, according to a report in the Journal of General Virology.
Scientists say strong evidence is needed to show that the actual virus that causes polio has disappeared completely. Further research into the complex virus – such as host interactions and how the vaccine is used in the final stages of the eradication program – will be needed.
Outbreaks of polio or poliomyelitis, also known as infantile paralysis, caused waves of fear around the world throughout the 1950s. However, by the mid 1970s, thanks to strident vaccination programs, the viral disease was under control, and had been eradicated from the developed world.
At the beginning of the 21st century, countries in the Indian subcontinent and central Africa were the only nations where polio was still endemic. And for the first time, India reported no cases of polio this year.
The team discovered two streams of stars, in the Milky Way’s southern galactic hemisphere, that were torn off the Sagittarius dwarf galaxy.
They found that these new star streams connect with two previously-known streams in the northern galactic hemisphere. The research team came to their conclusions from analyzing data from the latest Sloan Digital Sky Survey (SDSS-III).
“We have long known that when small dwarf galaxies fall into bigger galaxies, elongated streams, or tails, of stars are pulled out of the dwarf by the enormous tidal field,” research team co-leader Sergey Koposov said.
Astronomers say that, at one time, the Sagittarius dwarf galaxy was one of the brightest of those surrounding the Milky Way. Its disrupted remnant now lies on the other side of our galaxy, breaking up as it is crushed and stretched by huge tidal forces. In fact, the Sagittarius dwarf galaxy is so small that it has lost half of its stars and all of its gas over the last billion years.
They wanted to address the shortcomings of a therapeutic technique called Functional Electrical Stimulation (FES), which was developed to help patients with injuries to the spinal cord, upper or lower extremities and other nerve damage related injuries.
The devices stimulate neuronal activity in nerve-damaged patients, but the electrical currents needed to make the treatment work can send errant signals to surrounding nerves, resulting in painful side effects.
The BIDMC and MIT teams developed a new method of nerve stimulation that reduces the stimulation device’s electrical threshold by 40 percent as compared with traditional FES therapy.
According to the research, the supercooled liquid water becomes ice at -55 F not just because of the extreme cold, but because at that temperature, the actual molecular structure of water changes physically to form tetrahedron shapes, with each water molecule loosely bonded to four others.
The researchers say that their findings, published in Nature, suggest that a structural change from liquid to something they call “intermediate ice” explains the mystery of what determines the temperature at which water is going to freeze.
Soon you might be able to lose weight just by chewing a stick of gum or by taking a pill.
A team of scientists led by Syracuse University chemist Robert Doyle has demonstrated, that a hormone which helps people feel full after eating can be delivered into the bloodstream orally.
Called human PYY, the hormone is part of our chemical system that regulates appetite and energy.
Whenever you eat or exercise, the PYY is released into your bloodstream. The amount of this hormone that’s released into your system increases with the number of calories you consume. So, the more calories you take in, the more PYY hormones are produced and released.
Past research shows that people who are obese tend to have lower concentrations of PYY in their bloodstream than their thinner friends, both after eating and even when they’re fasting.
The research team found that an intravenous infusion of PYY, into a volunteer group of both obese and non-obese individuals, increased the serum levels of the hormone while lowering the number of calories both groups consumed, suggesting that when the amount of the PYY hormone is increased, you’ll eat less.
But, there’s a problem that the research team must address before they can continue their work developing this potential weight loss method.
It turns out that when the PYY hormone is taken orally, it gets destroyed in the stomach and that any amount of PYY that isn’t destroyed has difficulty getting into the bloodstream through the intestines.
So, the researchers’ next step is to find ways to get around this problem and deliver the PYY hormone into the system by using items such as chewing gum or an oral tablet to help people to lose weight.
As the list of newly discovered exoplanets continues to grow, some scientists worry the search for extra-terrestrial life will narrow, focusing on just a few of these new worlds, especially those with Earth-like conditions.
That’s because the scientific community’s search for alien life is widely based on the idea that Earth serves as the best model when considering which conditions that are best suited to hold life on other planets.
In other words, many scientists tend to look at a planet that either mimics, or merely has some of the important traits of Earth, before considering a search for extra-terrestrial life.
However, other scientists see that approach as a limiting form of earthling-biased thinking.
The team is proposing to narrow the search for extra-terrestrial life based on two basic questions: whether Earth-like conditions can be found on other worlds – since its’ already known that those conditions can harbor life – and whether conditions exist on exoplanets that suggest the possibility of other forms of life, whether known to us or not.
In a paper to be published in Astrobiology, the team suggests a new system for classifying exoplanets by using two different indices.
One would be an Earth Similarity Index (ESI) for categorizing a planet’s more earth-like features. The second is a Planetary Habitability Index (PHI), which describes a variety of chemical and physical parameters that are theoretically conducive to life in conditions unlike those on Earth.
“Habitability in a wider sense is not necessarily restricted to water as a solvent or to a planet circling a star,” the paper’s authors write. “For example, the hydrocarbon lakes on Titan could host a different form of life. Analog studies in hydrocarbon environments on Earth, in fact, clearly indicate that these environments are habitable in principle. Orphan planets wandering free of any central star could likewise conceivably feature conditions suitable for some form of life.”
The 19-year study involved more than 200 males, between the ages of 12 to 31, who lived in neighborhoods with higher-than-average rates of juvenile delinquency.
Researchers wanted to see how the subjects’ criminal behavior changed as they moved through adolescence into adulthood. The study also assessed how the men’s tobacco, alcohol and marijuana use evolved over that same period.
“These decreases were in addition to the general tendency of boys to engage less in these types of behaviors as they approach and enter adulthood,” says study lead author David Kerr, an assistant professor of psychology at Oregon State University.
Looking at the influences of peer pressure on anti-social behavior and substance abuse, Kerr says men tend to spend less time with their childless peers once they become fathers.
They also devote more time to their immediate and extended families, possibly in church and community service, settings that are somewhat incompatible with behaviors like substance abuse and criminal behavior.
Professor David Kerr, study lead author (Photo: Oregon State University)
However, not all first-time fathers are pushed into making a change. Instead, they want to change or are drawn into taking positive steps to become a better person.
For example, Kerr says many men may be drawn to fatherhood as a demonstration of masculinity, which shows they can protect and provide for their families.
Men who were in their late 20s and early 30s when they became fathers showed greater decreases in crime and alcohol use as compared to those who had their first child much earlier, like in their teens or early 20s.
Kerr says that could be because men who had children later might have been more able or willing to embrace fatherhood and shed negative lifestyle choices.
“This research suggests that fatherhood can be a transformative experience, even for men engaging in high risk behavior,” Kerr says, adding that new fathers might be especially willing and ready to hear a more positive message and make behavioral changes.
David Kerr joins us this weekend on the radio edition of “Science World.” He’ll tell us how fatherhood can help men overcome bad habits. So, either tune into the show (see right column for scheduled times) or check out the interview below.
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A Soyuz TMA-22 spacecraft carrying the three newest members of the ISS crew launched from the Baikonur Cosmodrome in Kazakhstan on Monday, Nov. 14, at 0414 UTC.
The spacecraft, with NASA astronaut Dan Burbank and Russian cosmonauts Anton Shkaplerov and Anatoly Ivanishin aboard, docked to the International Space Station’s Poisk mini-research module.
The trio joins the rest of the current ISS Expedition crew, including Commander Mike Fossum of NASA and flight engineers Satoshi Furukawa of the Japan Aerospace Exploration Agency and Russian cosmonaut Sergei Volkov.
The six station crew members have less than a week together before Fossum, Furukawa and Volkov head home on Monday, Nov. 21 aboard the Soyuz TMA-02M spacecraft, which brought them to the station on June 9. Their departure will mark the end of Mission 29 and the beginning of ISS Expedition 30.
Three more people will soon join the Expedition 30 crew. NASA astronaut Don Pettit, Russian cosmonaut Oleg Kononenko and European Space Agency astronaut Andre Kuipers are scheduled to launch to the station Dec. 21.
David Rand, a post-doctoral fellow at Harvard and lead author of the study, found that dynamic, complex social networks encourage their members to be friendlier and more cooperative.
The possible payoff is an expanded social sphere, while selfish behavior can lead to an individual being shunned from the group and left to fend for themselves.
“Although people sometimes do nasty things to each other, for the most part, we are fantastically cooperative,” Rand says. “We do an amazing job of having thousands, or even millions, of people living in very close quarters in cities all over the world. In a functioning society, things like trade, friendship, even democracy itself, require high levels of cooperation, and when everyone does it, you get good collective outcomes.”
This study is one of the first to examine social interaction as a fluid, ever-changing process. Rand describes this new approach as the closest scientists have been able to describe the way our planet’s six billion inhabitants interact with each other on a daily basis.
Cell phone battery (Photo: Vaky z via Wikimedia Commons
For those who rely on the latest technological gadgets to get through a busy work day, nothing can be more frustrating, or irritating, than a dead or dying battery in your cell phone, laptop or PDA.
Those days might soon be over.
Research engineers from Northwestern University say they’re close to developing a battery that stays charged for more than a week and can be recharged in just 15 minutes.
They’ve created an electrode for lithium-ion batteries – rechargeable batteries found in a number of portable electronic devices – that allows batteries to hold a charge up to 10 times greater than current technology. Batteries with the new electrode also can charge 10 times faster than current batteries.
Along with providing more efficient batteries for devices such as cellphones and MP3 players, the technology behind this potential “super battery” could also pave the way for more efficient, smaller batteries for electric cars.
The researchers predict the technology could hit the marketplace in the next three-to-five years.
The study finds increased air pollution and other particulate matter in the atmosphere can strongly affect cloud development in ways that reduce precipitation in dry regions or seasons, while increasing rain, snowfall and the intensity of severe storms in wet regions or seasons.
The researchers say their study provides the first clear evidence of how aerosols – including soot, dust and other small particles in the atmosphere – can affect weather and climate.
“We have uncovered, for the first time, the long-term, net impact of aerosols on cloud height and thickness, and the resultant changes in precipitation frequency and intensity,” says Zhanqing Li, lead author of the study.
So here’s another post with a good answer to the nagging question; will Earth be destroyed by a killer solar flare? In a word, according to NASA, no.
Yes, we here on terra firma do get banged and zapped from time to time by great bursts of electromagnetic energy and particles from the sun. That can cause disruptions to satellite and other forms of electronic communications, as well as jeopardize segments of our power grid.
In today’s technologically-rich environment, those outbursts from the sun can be a bit more than inconvenient. But, it appears that more and more people seem to be getting worked up over the Earth coming to an abrupt end, courtesy of a catastrophic blast from the sun.
A date inscription for the Mayan Long Count (Photo: Maunus via Creative Commons)
For some, this fear has been heightened by the so-called the “2012 phenomenon.” The Mayan long count calendar finishes its 5,125-year-long cycle on Dec. 21, 2012, and some believe that will result in the destruction of our planet due to any number of terrestrial or extraterrestrial calamities.
Some believe it will be in the form of a gigantic killer solar flare, which would hurl enough of the sun’s energy at us to destroy Earth. Couple the 2012 phenomenon with the fact that solar activity is ramping up in its standard 11-year cycle, and more credence is given to those who believe the sun will be the cause of Earth’s undoing.
But please be assured that this same solar cycle, which peaks with something called the solar maximum, has repeated itself over and over many times throughout the millennia.
If you’re older than 11, you’ve already lived through at least one solar maximum with no harm done. To those worried about its effect on the 2012 phenomenon, the next solar maximum is predicted to occur in late 2013 or early 2014, not 2012.
NASA assures us, most importantly, that there simply isn’t enough energy in the sun to hurl a killer fireball 93 million miles to destroy Earth.
2010 Global Carbon Dioxide Levels Hit Record High
Smoke billows from a coal-fired power plant (AP Photo/Charlie Riedel, file)
Every year around October 28, a part of Tom Boden’s job is to enter new data taken from global and national estimates of carbon emissions due to fossil-fuel combustion and cement manufacturing into a US Government database/dataset that contains information related to yearly carbon output going back to the year 1751. As he fed in this year’s data, Tom and his colleagues noticed that the new numbers seemed to be quite higher than usual, in fact they questioned whether they should believe them or not since the information was so compelling.
Tom Boden is the director of the Carbon Dioxide Information Analysis Center (CDIAC), which is located at the US Department of Energy’s Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The CDIAC is the primary climate-change data and information analysis center of the US Department of Energy (DOE).
On a global scale, some 9,139 teragrams – a teragram is a million metric tons – of oxidized carbon were emitted from fossil-fuel combustion and cement manufacture. This represents an increase of about 512 teragrams, or 5.9%, over the 2009 global estimate. In 2008, 8,749 teragrams were emitted worldwide making the 2010 estimate about 104.5% of that, or 391 teragrams more. When all of this oxidized carbon, along with the mass from oxygen molecules, is converted to carbon dioxide (CO2), we’re looking at amounts of over 33.5 billion metric tons of carbon dioxide being dumped into the atmosphere in 2010.
Tom Boden, Carbon Dioxide Information Analysis Center - US Department of Energy
Among factors scientists considered when determining reasons why levels of carbon rose or fell over this three year period (2008 through 2010) were the global financial and economic crisis that started in 2008. Boden and his colleagues were a bit surprised that the impact of the financial crisis didn’t result in lower global numbers, but instead jumped even higher than previous years.
Much of that 5.9% global increase from 2009 to 2010, according the latest estimates, is due to increased emissions from the world’s largest fossil-fuel emitter, the People’s Republic of China, where emissions rose by 10%. 2010 carbon emissions from the United States were up by almost 4%, of the 2009 estimates. But when comparing this recent data with the numbers from 2007, the record high year for the US, the 2010 carbon output was 6% less. The recent set of estimates also show that other countries had similar experiences. While a number of nations did have decreases in the amount of emitted carbon, Boden says “the big story here is some of the large increases in the developing countries.”
The estimates the CDIAC generates are from underlying statistics that are reported by a number of sources including the United Nations, The International Energy Agency in Paris, related agencies from individual countries, for example the United States information is from the US Department of Energy, among others and data that is produced by private companies such as British Petroleum (BP).
If you want to examine the Carbon Dioxide Information Analysis Center carbon emission estimates and check out similar data from the past you can do so by visiting their web site.
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A lot of folks on Earth breathed a collective sigh of relief when an asteroid, the size of an aircraft carrier, sailed past us without causing any harm.
Yesterday, Nov. 8, 2011 at approximately 2328 UTC, the asteroid 2005 YU55 came within 324,604.685 kilometers of Earth, making it the biggest asteroid in 35 years to have such a close encounter with Earth. The space rock came closer to us than our own moon.
Scientists tracking the asteroid’s trajectory believed all along that it didn’t pose any real danger to us. Also, the gravitational influence of the asteroid shouldn’t have any detectable impact on Earth, including its tides and tectonic plates.
The last time such a huge space rock came that close to Earth was in 1976, and astronomers didn’t even know about it until afterward. The next known approach of an asteroid this large will be in 2028.
The Zenit-2SB rocket with Phobos-Grunt craft blasts off from the Cosmodrome in Baikonur, Kazakhstan, early Wednesday, Nov. 9, 2011. (AP Photo/Oleg Urusov, Pool)
In other space news, the Russian space program suffered another setback Tuesday when its first planned interplanetary mission in almost two decades failed to take its proper course toward Mars. It is now stuck orbiting Earth.
Russian space agency chief Vladimir Popovkin said an engine failed to fire on the 5-billion-ruble ($163 million) Phobos-Grunt probe after it reached Earth’s orbit.
“The engine did not fire, neither the first nor the second burn occurred. This means that the craft was unable to find its bearings by the stars,” the Interfax news agency quoted Popovkin as saying at Russia’s Baikonur launch facility in Kazakhstan.
This leaves Moscow space officials with a limited amount of time to yank the probe out of its current orbit and back onto its path toward Mars before the spacecraft’s batteries are completely drained.
If the problem isn’t fixed, not only will the Russian probe’s mission to the Mars moon Phobos be in danger, but also that of China’s first interplanetary spacecraft. The tiny Yinghuo-1 was launched with Phobos-Grunt and is to work with it in orbit, studying the atmosphere of Mars for a year.
Water… good ole H20, one of the simplest chemical compounds, is providing chemists with an odd twist. When chilled below the freezing point, it can shift into a new type of liquid, according to a report in the Journal of Physical Chemistry B.
Researchers, Pradeep Kumar of New York’s Rockefeller University and H. Eugene Stanley of Boston University, say water is one weird substance, exhibiting more than 80 unusual properties, some of which scientists are struggling to understand.
For example, they say, water can exist in all three states of matter – solid, liquid and gas – at the same time, and that the forces at its surface enable insects to walk on water, and cause water to rise up from the roots into the leaves of trees and other plants.
In another strange turn, the scientists propose that water can go from being one type of liquid into another in a so-called “liquid-liquid” phase transition. However, they also say it is impossible to test this with today’s laboratory equipment because these things happen so fast.
So the researchers here resorted to computer simulations to check it out.
What they learned was when they chilled liquid water in their simulation, its ability to conduct heat decreased. That’s expected for an ordinary liquid. But, when they lowered the temperature to about 54 degrees below zero Fahrenheit, the liquid water started to conduct heat even better in their simulation.
Their research suggests that, below this temperature, liquid water undergoes sharp but continuous structural changes where the local structure of liquid becomes extremely ordered – very much like ice. These structural changes in liquid water lead to an increase of heat conduction at lower temperatures.
The researchers say this surprising result supports the idea that water has a liquid-liquid phase transition.
Drosophila melanogaster aka the common fruit-fly (Photo: André Karwath (Own work) via Wikimedia Commons)
Scientists at UCLA might be on the road to discovering the “fountain of youth.” Life scientists at the California university say they’ve identified a gene which slows the aging process.
Working with fruit flies, the scientists activated a gene called PGC-1, which increases the activity of mitochondria, the tiny power generators in cells that control cell growth and tell cells when to live and die.
“We took this gene and boosted its activity in different cells and tissues of the fly and asked whether this impacts the aging process,” says UCLA’s David Walker, senior author of the study. “We discovered that when we boost PGC-1 within the fly’s digestive tract, the fly lives significantly longer.”
Just activating this one gene in the fruit fly’s intestine caused the aging process of the intestine to slow, producing a positive effect on the entire insect itself, according to Walker.
The biologists say that they were able to extend the lives of their fruit-fly specimen by as much as 50 percent.
A nurse in northern Ethiopia prepares a measles vaccine. (Photo: Pete Lewis/Department for International Development)
The discovery of how measles spreads could lead to promising new approaches in treating cancer, according to a new study published in Nature.
Measles – the leading cause of death among young children, according to the World Health Organization – is commonly spread through coughing or sneezing.
Scientists say this method of transmission explains why the virus spreads so quickly and how it’s remained resistant to worldwide vaccination programs designed to eradicate it.
In order to start and spread an infection throughout an organism, viruses generally use cell receptors, which are molecules that receive signals from other cells. This is no different for the measles virus, which enters and spreads throughout the body by infecting the immune cells in the lungs.
An international team of researchers recently discovered the measles virus leaves its host through a receptor called nectin-4, which is located in the trachea. Scientists say the trachea is a part of the human body that is ideally suited to airborne infection.
Scientists say nectin-4 is a biomarker for certain types of cancer such as breast, ovarian and lung cancers.
Since measles actively targets nectin-4, scientists are working on ways to use a modified version of the measles virus to attack cancer cells.
Those clinical trials are now under way.
The scientists are hopeful measles-based therapy will prove more successful in treating some cancer patients, while being less toxic than chemotherapy or radiation.
$10 Million Prize Offered for Quick, Cheap Genetic Test
Ten million dollars is up for grabs to the first team of scientists which can accurately sequence the genetic code of 100 centenarians within 30 days, and do it for up to $1,000 per person.
The huge monetary prize is offered by the X PRIZE Foundation,which seeks to encourage “radical breakthroughs for the benefit of humanity.”
The foundation made headlines back in 2004, after awarding $10 million to Mojave Aerospace Ventures, a private company which built and launched the first manned private spaceflight.
The results of the latest competition could set a new clinical standard for genomic sequencing, according to foundation officials. They also hope the research findings will help usher in a new era of personalized medicine.
Grant Campany, senior director of the Archon Genomics X PRIZE, says a main reason for the competition is that there is currently no standard way of measuring the quality of whole genome sequences, which has hindered the development of medical and diagnostic applications of whole genomic sequencing.
Although there are a number of companies that provide genomic sequencing, Campany says they often derive different results from the same DNA. As a result, crucial research is limited because doctors and scientists don’t have a high level of confidence in the various results.
The 100 subjects whose genomes will be sequenced in this competition aren’t just anyone. Each of the selected subjects will be at least 100 years old. Called the “Medco 100 Over 100,” the centenarian subjects are being recruited through a worldwide public search. Anyone 100 years of age or older can be nominated to participate in the research effort. The nomination process can be completed online at the Archon X-Prize website.
Campany says the foundation asked the scientific community which group of people would be best for this study. The almost unanimous choice was the oldest of the old. Sequencing the genomes of those 100 and older will give researchers an unprecedented opportunity to identify rare genes which protect against diseases, yielding valuable clues to health and longevity.
Along with the competition itself, prize organizers have created an online community to showcase the centenarian subjects. Called “Life at 100,” it will allow the centenarians and their families to create profiles and display their photos and videos, providing a means for them to share their personal experiences with the public.
Once the competition ends in February 2013, the X-PRIZE Foundation will compile a public database of the DNA sequences and cell lines from the “Medco 100 Over 100” genomes. Researchers and scientists worldwide will be allowed open access to the incredibly rich and unique data. Officials say the knowledge gained by compiling and comparing the results will further the understanding of health and longevity, possibly decoding its secrets, leading to radical medical breakthroughs.
Grant Campany joins us this weekend on the radio edition of “Science World.” Campany will talk about the competition, what they hope to learn from it and how it could someday benefit mankind. So, either tune into the show (see right column for scheduled times) or check out the interview below.
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Other stories we cover on the “Science World” radio program this week include: