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Surgeons implant first brain ‘pacemaker’ for Alzheimer’s disease in US

Surgeons implant first brain ‘pacemaker’ for Alzheimer’s disease in US | Science Communication from mdashf | Scoop.it
Researchers at Johns Hopkins Medicine have surgically implanted a pacemaker-like device into the brain of a patient in the early stages of Alzheimer’s disease, the first such operation in the United States.

The device, which provides deep brain stimulation and has been used in thousands of people with Parkinson’s disease, is seen as a possible means of boosting memory and reversing cognitive decline. Instead of focusing on drug treatments, many of which have failed in recent clinical trials, the research focuses on the use of the low-voltage electrical charges delivered directly to the brain. There is no cure for Alzheimer’s disease yet.

 

The surgery is part of a federally funded, multicenter clinical trial marking a new direction in clinical research designed to slow or halt the ravages of the disease, which slowly robs its mostly elderly victims of a lifetime of memories and the ability to perform the simplest of daily tasks, researchers at Johns Hopkins say. Some 40 patients are expected to receive the deep brain stimulation implant over the next year or so at Johns Hopkins and four other institutions in North America as part of the Advance Study led by Constantine G. Lyketsos, M.D., M.H.S., a professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, and Andres Lozano, M.D., Ph.D., chairman of the neurology department at the University of Toronto. Only patients whose cognitive impairment is mild enough that they can decide on their own to participate will be included in the trial. Other sites performing the operation, supported by the National Institutes of Health’s National Institute on Aging (R01AG042165), are the University of Toronto, the University of Pennsylvania, the University of Florida, and Banner Health System in Phoenix, Ariz. The medical device company, Functional Neuromodulation Ltd., is also supporting the trial.

 

While experimental for Alzheimer’s patients, more than 80,000 people with the neurodegenerative disorder Parkinson’s disease have undergone the procedure over the past 15 years, with many reporting fewer tremors and requiring lower doses of medication afterward, Lyketsos says. Other researchers are testing deep brain stimulation to control depression and obsessive-compulsive disorder resistant to other therapies. The surgery involves drilling holes into the skull to implant wires into the fornix on either side of the brain. The fornix is a brain pathway instrumental in bringing information to the hippocampus, the portion of the brain where learning begins and memories are made, and where the earliest symptoms of Alzheimer’s appear to arise. The wires are attached to a pacemaker-like device, the “stimulator,” which generates tiny electrical impulses into the brain 130 times a second. The patients don’t feel the current, Rosenberg says. “Deep brain stimulation might prove to be a useful mechanism for treating Alzheimer’s disease, or it might help us develop less invasive treatments based on the same mechanism,” Rosenberg says. By 2050, the number of people age 65 and older with Alzheimer’s disease may triple, experts say, from 5.2 million to a projected 11 million to 16 million, unless effective treatments are found.


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Could synthetic fuels eliminate entire US need for crude oil, create ‘new economy’?

Could synthetic fuels eliminate entire US need for crude oil, create ‘new economy’? | Science Communication from mdashf | Scoop.it

The U.S. could eliminate the need for crude oil by using a combination of coal, natural gas, and non-food crops to make synthetic fuel, a team of Princeton researchers has found. Besides economic and national security benefits, the plan has potential environmental advantages. Because plants absorb carbon dioxide to grow, the United States could cut vehicle greenhouse emissions by as much as 50 percent in the next several decades using non-food crops to create liquid fuels, the researchers said.

 

Synthetic fuels would be an easy fit for the transportation system because they could be used directly in automobile engines and are almost identical to fuels refined from crude oil. That sets them apart from currently available biofuels, such as ethanol, which have to be mixed with gas or require special engines.

 

In a series of scholarly articles over the past year, a team led by Christodoulos Floudas, a professor of chemical and biological engineering at Princeton, evaluated scenarios in which the U.S. could power its vehicles with synthetic fuels rather than relying on oil. Floudas’ team also analyzed the impact that synthetic fuel plants were likely to have on local areas and identified locations that would not overtax regional electric grids or water supplies.

 

“The goal is to produce sufficient fuel and also to cut CO2 emissions, or the equivalent, by 50 percent,” said Floudas, the Stephen C. Macaleer ’63 Professor in Engineering and Applied Science. “The question was not only can it be done, but also can it be done in an economically attractive way. The answer is affirmative in both cases.”


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Cassini Solstice Mission: Hexagonal Storm Pattern On Saturn's North Pole

Cassini Solstice Mission: Hexagonal Storm Pattern On Saturn's North Pole | Science Communication from mdashf | Scoop.it

What's happening at the north pole of Saturn? A vortex of strange and complex swirling clouds. The center of this vortex was imaged in unprecedented detail last week by the robotic Cassini spacecraft orbiting Saturn. These clouds lie at the center of the unusual hexagonal cloud system that surrounds the north pole of Saturn. The sun rose on Saturn's north pole just a few years ago, with Cassini taking only infrared images of the shadowed region previously. The above image is raw and unprocessed and is being prepared for release in 2013. Several similar images of the region have recently been condensed into a movie. Planetary scientists are sure to continue to study this most unusual cloud formation for quite some time.


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Researchers discover fastest light-driven process - 10,000 times faster than today's transistors

Researchers discover fastest light-driven process - 10,000 times faster than today's transistors | Science Communication from mdashf | Scoop.it

Professor of Physics Mark Stockman worked with Professor Vadym Apalkov of Georgia State and a group led by Ferenc Krausz at the prestigious Max Planck Institute for Quantum Optics and other well-known German institutions.

 

There are three basic types of solids: metals, semiconductors, used in today's transistors, and insulators – also called dielectrics. Dielectrics do not conduct electricity and get damaged or break down if too high of fields of energy are applied to them. The scientists discovered that when dielectrics were given very short and intense laser pulses, they start conducting electricity while remaining undamaged. The fastest time a dielectric can process signals is on the order of 1 femtosecond – the same time as the light wave oscillates and millions of times faster than the second handle of a watch jumps. Dielectric devices hold promise to allow for much faster computing than possible today with semiconductors. Such a device can work at 1 petahertz, while the processor of today's computer runs slightly faster than at 3 gigahertz.

 

"Now we can fundamentally have a device that works 10 thousand times faster than a transistor that can run at 100 gigahertz," Stockman said. "This is a field effect, the same type that controls a transistor. The material becomes conductive as a very high electrical field of light is applied to it, but dielectrics are 10,000 times faster than semiconductors."


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A Breakthrough Against Leukemia Using Altered T-Cells

A Breakthrough Against Leukemia Using Altered T-Cells | Science Communication from mdashf | Scoop.it

Emma Whitehead, 7, has been in full remission for months after scientists used a disabled form of H.I.V. to reprogram her immune system to kill cancer cells. Emma had been ill with acute lymphoblastic leukemia since 2010, when she was 5, said her parents, Kari and Tom. She is their only child. She is among just a dozen patients with advanced leukemia to have received the experimental treatment, which was developed at the University of Pennsylvania. Similar approaches are also being tried at other centers, including the National Cancer Institute and Memorial Sloan-Kettering Cancer Center in New York.

 

“Our goal is to have a cure, but we can’t say that word,” said Dr. Carl June, who leads the research team at the University of Pennsylvania. He hopes the new treatment will eventually replace bone-marrow transplantation, an even more arduous, risky and expensive procedure that is now the last hope when other treatments fail in leukemia and related diseases.

 

Three adults with chronic leukemia treated at the University of Pennsylvania have also had complete remissions, with no signs of disease; two of them have been well for more than two years, said Dr. David Porter. Four adults improved but did not have full remissions, and one was treated too recently to evaluate. A child improved and then relapsed. In two adults, the treatment did not work at all. The Pennsylvania researchers were presenting their results on Sunday and Monday in Atlanta at a meeting of the American Society of Hematology.

 

Despite the mixed results, cancer experts not involved with the research say it has tremendous promise, because even in this early phase of testing it has worked in seemingly hopeless cases. “I think this is a major breakthrough,” said Dr. Ivan Borrello, a cancer expert and associate professor of medicine at the Johns Hopkins University School of Medicine.

 

The University of Pennsylvania team seems to have hit all the targets at once. Inside the patients, the T-cells modified by the researchers multiplied to 1,000 to 10,000 times the number infused, wiped out the cancer and then gradually diminished, leaving a population of “memory” cells that can quickly proliferate again if needed. The researchers said they were not sure which parts of their strategy made it work — special cell-culturing techniques, the use of HIV1 to carry new genes into the T-cells, or the particular pieces of DNA that they selected to reprogram the T-cells.

 

The concept of doctoring T-cells genetically was first developed in the 1980s by Dr. Zelig Eshhar at the Weizmann Institute of Science in Rehovot, Israel. It involves adding gene sequences from different sources to enable the T-cells to produce what researchers call chimeric antigen receptors, or CARs — protein complexes that transform the cells into “serial killers.”

 

Chronic lymphocytic leukemia is a cancer of B-cells, the part of the immune system that normally produces antibodies to fight infection. All B-cells, whether healthy or leukemic, have on their surfaces a protein called CD19. To treat patients with the disease, the researchers hoped to reprogram their T-cells to find CD19 and attack B-cells carrying it.

 

But which gene sequences should be used to reprogram the T-cells, from which sources? And how do you insert them? Various research groups have used different methods. Viruses are often used as carriers (or vectors) to insert DNA into other cells because that kind of genetic sabotage is exactly what viruses normally specialize in doing. To modify their patients’ T-cells, researchers tried a daring approach: they used a disabled form of HIV1 as the vector in gene therapy for cancer patients (the virus has been used in other diseases). The AIDS virus is a natural for this kind of treatment, because it evolved to invade T-cells. The idea of putting any form of the AIDS virus into people sounds a bit frightening, but the virus used here was considered no longer harmful. Other researchers had altered and disabled the virus by adding DNA from humans, mice and cows, and from a virus that infects woodchucks and another that infects cows.

To administer the treatment, the researchers collected as many of the patients’ T-cells as they could by passing their blood through a machine that removed the cells and returned the other blood components back into the patients’ veins. The T-cells were exposed to the vector, which transformed them genetically, and then were frozen. Meanwhile, the patients were given chemotherapy to deplete any remaining T-cells, because the native T-cells might impede the growth of the altered ones. Finally, the T-cells were infused back into the patients.


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Caltech engineers have created a device that can focus light into a single point just a few nanometers across

Caltech engineers have created a device that can focus light into a single point just a few nanometers across | Science Communication from mdashf | Scoop.it
As technology advances, it tends to shrink. From cell phones to laptops—powered by increasingly faster and tinier processors—everything is getting thinner and sleeker. And now light beams are getting smaller, too.

Engineers at the California Institute of Technology (Caltech) have created a device that can focus light into a point just a few nanometers (billionths of a meter) across—an achievement they say may lead to next-generation applications in computing, communications, and imaging. Because light can carry greater amounts of data more efficiently than electrical signals traveling through copper wires, today's technology is increasingly based on optics. The world is already connected by thousands of miles of optical-fiber cables that deliver email, images, and the latest video gone viral to your laptop. As we all produce and consume more data, computers and communication networks must be able to handle the deluge of information. Focusing light into tinier spaces can squeeze more data through optical fibers and increase bandwidth. Moreover, by being able to control light at such small scales, optical devices can also be made more compact, requiring less energy to power them. But focusing light to such minute scales is inherently difficult. Once you reach sizes smaller than the wavelength of light—a few hundred nanometers in the case of visible light—you reach what's called the diffraction limit, and it's physically impossible to focus the light any further. But now the Caltech researchers, co-led by assistant professor of electrical engineering Hyuck Choo, have built a new kind of waveguide—a tunnellike device that channels light—that gets around this natural limit. The waveguide is made of amorphous silicon dioxide—which is similar to common glass—and is covered in a thin layer of gold. Just under two microns long, the device is a rectangular box that tapers to a point at one end.

Instead of focusing the light alone—which is impossible due to the diffraction limit—the new device focuses these coupled electron oscillations, called surface plasmon polaritons (SPPs). The SPPs travel through the waveguide and are focused as they go through the pointy end. Because the new device is built on a semiconductor chip with standard nanofabrication techniques, says Choo, the co-lead and the co-corresponding author of the paper, it is easy integrate with today's technology Previous on-chip nanofocusing devices were only able to focus light into a narrow line. They also were inefficient, typically focusing only a few percent of the incident photons, with the majority absorbed and scattered as they traveled through the devices. With the new device, light can ultimately be focused in three dimensions, producing a point a few nanometers across, and using half of the light that's sent through, Choo says. (Focusing the light into a slightly bigger spot, 14 by 80 nanometers in size, boosts the efficiency to 70 percent). The key feature behind the device's focusing ability and efficiency, he says, is its unique design and shape.
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Animal Planet Wrong About Dinosaurs: Study Shows They Were Much Skinnier

Animal Planet Wrong About Dinosaurs: Study Shows They Were Much Skinnier | Science Communication from mdashf | Scoop.it
According to researchers, shows about dinosaurs on Animal Planet and movies like that feature dinosaurs have shown these creatures incorrectly. They...

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Soil science adds to evidence for Maya collapse

Soil science adds to evidence for Maya collapse | Science Communication from mdashf | Scoop.it
New research documents in the soils of Mayan cities and settlements how they farmed, fed themselves and treated the land and perhaps even why their society ultimately declined...

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Hubble Space Telescope Directly Observes Exoplanet

Hubblecast: 40 Videos

 

The NASA/ESA Hubble Space Telescope has discovered an extrasolar planet, for the first time using direct visible-light imaging. The strange world is far-flung from its parent star, is surrounded by a colossal belt of gas and dust, and may even have rings more impressive than Saturn's.


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Time's quantum arrow has a preferred direction: BaBar experiment confirms time asymmetry

Time's quantum arrow has a preferred direction: BaBar experiment confirms time asymmetry | Science Communication from mdashf | Scoop.it
Time marches relentlessly forward for you and me; watch a movie in reverse, and you'll quickly see something is amiss. But from the point of view of a single, isolated particle, the passage of time looks the same in either direction. For instance, a movie of two particles scattering off of each other would look just as sensible in reverse – a concept known as time reversal symmetry.

 

Now the BaBar experiment at the Department of Energy's (DOE) SLAC National Accelerator Laboratory has made the first direct observation of a long-theorized exception to this rule. Digging through nearly 10 years of data from billions of particle collisions, researchers found that certain particle types change into one another much more often in one way than they do in the other, a violation of time reversal symmetry and confirmation that some subatomic processes have a preferred direction of time. The results are impressively robust, with a 1 in 10 tredecillion (10E43) or 14-sigma level of certainty – far more than needed to declare a discovery.

 

"It was exciting to design an experimental analysis that enabled us to observe, directly and unambiguously, the asymmetrical nature of time," said BaBar collaborator Fernando Martínez-Vidal, associate professor at the University of Valencia and member of the Instituto de Fisica Corpuscular (IFIC), who led the investigation. "This is a sophisticated analysis, the kind of experimental work that can only be done when an experiment is mature."

 

BaBar, which collected data at SLAC from 1999 to 2008, was designed to tease out subtle differences in the behavior of matter and antimatter that might help account for the preponderance of matter in the universe. It produced almost 500 million pairs of particles called B mesons and their antimatter counterparts B-bar mesons for study. BaBar scientists found that B mesons and B-bar mesons do, indeed, behave differently in ways that violate so-called CP symmetry, which incorporates the symmetries of charge (positive versus negative) and parity (which can be thought of as left-handedness versus right-handedness). This discovery of CP violation contributed to the 2008 Nobel Prize in Physics.


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Patricio Díaz's curator insight, October 20, 2013 6:02 PM

La Teoría Cuántica confirma la asimetría del tiempo

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Time's quantum arrow has a preferred direction: BaBar experiment confirms time asymmetry

Time's quantum arrow has a preferred direction: BaBar experiment confirms time asymmetry | Science Communication from mdashf | Scoop.it
Time marches relentlessly forward for you and me; watch a movie in reverse, and you'll quickly see something is amiss. But from the point of view of a single, isolated particle, the passage of time looks the same in either direction. For instance, a movie of two particles scattering off of each other would look just as sensible in reverse – a concept known as time reversal symmetry.

 

Now the BaBar experiment at the Department of Energy's (DOE) SLAC National Accelerator Laboratory has made the first direct observation of a long-theorized exception to this rule. Digging through nearly 10 years of data from billions of particle collisions, researchers found that certain particle types change into one another much more often in one way than they do in the other, a violation of time reversal symmetry and confirmation that some subatomic processes have a preferred direction of time. The results are impressively robust, with a 1 in 10 tredecillion (10E43) or 14-sigma level of certainty – far more than needed to declare a discovery.

 

"It was exciting to design an experimental analysis that enabled us to observe, directly and unambiguously, the asymmetrical nature of time," said BaBar collaborator Fernando Martínez-Vidal, associate professor at the University of Valencia and member of the Instituto de Fisica Corpuscular (IFIC), who led the investigation. "This is a sophisticated analysis, the kind of experimental work that can only be done when an experiment is mature."

 

BaBar, which collected data at SLAC from 1999 to 2008, was designed to tease out subtle differences in the behavior of matter and antimatter that might help account for the preponderance of matter in the universe. It produced almost 500 million pairs of particles called B mesons and their antimatter counterparts B-bar mesons for study. BaBar scientists found that B mesons and B-bar mesons do, indeed, behave differently in ways that violate so-called CP symmetry, which incorporates the symmetries of charge (positive versus negative) and parity (which can be thought of as left-handedness versus right-handedness). This discovery of CP violation contributed to the 2008 Nobel Prize in Physics.


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Patricio Díaz's curator insight, October 20, 2013 6:02 PM

La Teoría Cuántica confirma la asimetría del tiempo

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STEM Bill- Immigration reform that will give green cards to science, tech, engineering, math grads

STEM Bill- Immigration reform that will give green cards to science, tech, engineering, math grads | Science Communication from mdashf | Scoop.it

A blog dedicated to advancing constructive dialogue on immigration.

We need to fix our economy and unemployment situation before we encourage any other immigration and we must secure our border and enforce current law first.


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Keep European Science Competitive – Don’t Cut the European Research Council (ERC) Budget!

The Young Academy of Sweden has joined forces with the Young Academies of Germany, the Netherlands and Denmark to urge the leaders of the European Union to invest more, not less, in science in their upcoming budget (see go.nature.com/ymjole). Short-term savings would have long-term costs and weaken Europe's future scientific…

 

And by the way ... http://erc.europa.eu/

 


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Super-massive black hole with a mass half the size of its hosting galaxy

Super-massive black hole with a mass half the size of its hosting galaxy | Science Communication from mdashf | Scoop.it

A new survey recently reported in Nature found a supermassive black hole (mass~17 billions of solar masses) at the center of a relatively "light" galaxy. This wouldn't be a surprise if the mass of the black hole wasn't more than half the mass of the buldge of the hosting galaxy. The black line shows the mass–luminosity relation for galaxies with a directly measured black-hole mass.

 

NGC 1277 is a significant positive outlier. Indeed, we already know that most galaxies -- including our own Milky Way -- host supermassive black holes which lurk at the galactic center. Also, the mass of the black hole is believed to be tightly connected with the properties of the hosting galaxy. Several models of galaxy dynamics and mergers predict a black hole mass VS bulge luminosity relation similar to that shown in the Figure above and this has important implications in the understanding of the galaxy evolution and of black hole population models. Typically, the mass of the black hole is about 0.1 per cent of the mass of the stellar bulge of the galaxy and the maximum mass fraction observed so far was about 10%.

 

The discovery of NGC 1277, a compact, lenticular galaxy with a mass of roughly 1.2x10^11 solar masses, is particularly interesting because this galaxy hosts a black hole of mass about 1.7x10^10 solar masses, that is, roughly 59% of the total bulge mass. Indeed, it's evident in the Figure above how NGC 1277 deviates from the expected empirical behavior.

 

This discovery seems confirmed by other observations of galaxies that host oversized black holes and it might suggest a failure (or the need of some improvement) in current models.


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Flexible Silicon Solar-Cell Fabrics Soon? Wear a solar fiber jacket

Flexible Silicon Solar-Cell Fabrics Soon? Wear a solar fiber jacket | Science Communication from mdashf | Scoop.it

The first flexible, fiber-optic solar cell that can be woven into clothes. An international team of engineers, physicists, and chemists have created the first fiber-optic solar cell. These fibers are thinner than human hair, flexible, and yet they produce electricity, just like a normal solar cell. 

 

The research opens the door to the possibility of weaving together solar-cell silicon wires to create flexible, curved or twisted solar fabrics. The findings by an international team of chemists, physicists and engineers, led by John Badding, a professor of chemistry at Penn State, will be posted by the journal Advanced Materials in an early online edition today (Dec. 6) and will be published on a future date in the journal's print edition.

 

The team's new findings build on earlier work addressing the challenge of merging optical fibers with electronic chips -- silicon-based integrated circuits that serve as the building blocks for most semiconductor electronic devices such as solar cells, computers and cellphones. Rather than merge a flat chip with a round optical fiber, the team found a way to build a new kind of optical fiber -- which is thinner than the width of a human hair -- with its own integrated electronic component, thereby bypassing the need to integrate fiber-optics with chips. To do this, they used high-pressure chemistry techniques to deposit semiconducting materials directly, layer by layer, into tiny holes in optical fibers.

 

Now, in their new research, the team members have used the same high-pressure chemistry techniques to make a fiber out of crystalline silicon semiconductor materials that can function as a solar cell -- a photovoltaic device that can generate electrical power by converting solar radiation into direct-current electricity. "Our goal is to extend high-performance electronic and solar-cell function to longer lengths and to more flexible forms. We already have made meters-long fibers but, in principle, our team's new method could be used to create bendable silicon solar-cell fibers of over 10 meters in length," Badding said. "Long, fiber-based solar cells give us the potential to do something we couldn't really do before: We can take the silicon fibers and weave them together into a fabric with a wide range of applications such as power generation, battery charging, chemical sensing and biomedical devices."

 

Badding explained that one of the major limitations of portable electronics such as smartphones and iPads is short battery life. Solar-boosted batteries could help solve this problem. "A solar cell is usually made from a glass or plastic substrate onto which hydrogenated amorphous silicon has been grown," Badding explained. "Such a solar cell is created using an expensive piece of equipment called a PECVD (plasma-enhanced chemical vapor deposition) reactor and the end result is something flat with little flexibility. But woven, fiber-based solar cells would be lightweight, flexible configurations that are portable, foldable and even wearable." This material could then be connected to electronic devices to power them and charge their batteries. "The military especially is interested in designing wearable power sources for soldiers in the field," Badding added.

 

The team members believe that another advantage of flexibility in solar-cell materials is the possibility of collecting light energy at various angles. "A typical solar cell has only one flat surface," Badding said. "But a flexible, curved solar-cell fabric would not be as dependent upon where the light is coming from or where the sun is in the horizon and the time of day." 


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Oxygen nucleus with twice as many neutrons as normal is shown to be surprisingly stable

Oxygen nucleus with twice as many neutrons as normal is shown to be surprisingly stable | Science Communication from mdashf | Scoop.it
The nucleus at the heart of an atom is held together by a subtle balance between the nuclear force that binds protons and neutrons and the electric repulsion that tries to fling the positively charged protons apart. Understanding how the number of nucleons—the collective term for protons and neutrons—affects this balance is crucial for predicting nuclear processes such as radioactive decay. RIKEN researchers, working as part of an international team, have now shown that 'heavy' oxygen nuclei with 16 neutrons form into a solid ball, which makes them unexpectedly stable.

 

Tohru Motobayashi from the RIKEN Nishina Center for Accelerator-Based Science, collaborating with Yoshinori Satou from the Seoul National University, Korea, Takashi Nakamura from the Tokyo Institute of Technology, Japan, and co-workers from France, Hungary and China have now performed the first spectroscopic study of oxygen nuclei with 16 neutrons using a technique known as proton inelastic scattering. They fired a beam of these oxygen-24 atoms at a liquid-hydrogen target, and then extracted the properties of the neutron-rich nuclei by tracking the direction and speed of the particles after the collision.

 

A nucleus has either a spherical or elliptical shape depending on the number of neutrons and protons. "The nucleus is more stable and solid when it is spherical," explains Motobayashi. "In our experiments we can hear the sound associated with this solidity, just as you can when you strike an everyday solid object." An intriguing aspect of this result is that it runs contrary to the now well-established observation that nuclei are usually stable when the number of neutrons and protons corresponds to a so-called magic number: 2, 8, 20, 28, 50, 82 or 126. "We can now confirm that a neutron number of 16 is magic when proton and neutron numbers are largely unbalanced," says Motobayashi. "This supports other recent experiments on different nuclei." This cutting edge experiment is another example of the importance of the steadily growing research collaboration between RIKEN, the Tokyo Institute of Technology and a number of Korean universities. "We next hope to explore more neutron-rich oxygen isotopes with 17, 18 or more neutrons to see if another stable oxygen nucleus exists," says Motobayashi.


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How has the expansion of the Universe changed over time (say the last 10 Billion years)?

How has the expansion of the Universe changed over time (say the last 10 Billion years)? | Science Communication from mdashf | Scoop.it

For the past five-billion years, the expansion of the universe has been powered by a mysterious repulsive force known as "dark energy." Now, thanks to a new technique for measuring the three-dimensional structure of the distant universe, scientists in an international team within the Sloan Digital Sky Survey (SDSS-III), including an astronomer at Penn State University, have made the first measurement of the rate of this cosmic expansion as it was just three-billion years after the Big Bang.

 

"Observations in the past 15 years have revealed that the expansion rate of the universe is accelerating," said Donald Schneider, Distinguished Professor of Astronomy and Astrophysics at Penn State, a coauthor of the study. "Most cosmological models predict that when the universe was young, dark energy had little influence on the expansion; at that time the evolution of the large-scale structure of the universe was dominated by gravitation, which is an attractive force that acted to slow the expansion. The new SDSS-III observations are an important probe of this early era." Schneider is the Sloan Digital Sky Survey's survey coordinator and scientific publications coordinator.

 

The above graph shows how the universe's expansion rate has changed over the last 10-billion years. Until recently, three-dimensional maps by BOSS and other surveys were able to measure the regular distribution of galaxies back to only about five-and-a-half-billion years ago, a time when the expansion of the universe was already accelerating. The numbers along the bottom of the graph show the time in the universe's past, in billions of years. The vertical scale (y-axis) shows the expansion rate of the universe; higher means the universe was expanding faster.These older measurements appear as data points toward the right of the graph. The new SDSS-III measurements, shown as the data point to the far left, have now probed the structure of the early universe at a time when expansion was still slowing down.


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The very first stars may have turned on when the universe was only 750 million years old

The very first stars may have turned on when the universe was only 750 million years old | Science Communication from mdashf | Scoop.it

As far back in time as astronomers have been able to see, the universe has had some trace of heavy elements, such as carbon and oxygen. These elements, originally churned from the explosion of massive stars, formed the building blocks for planetary bodies, and eventually for life on Earth.

 

Now researchers at MIT, the California Institute of Technology, and the University of California at San Diego have peered far back in time, to the era of the first stars and galaxies, and found matter with no discernible trace of heavy elements. To make this measurement, the team analyzed light from the most distant known quasar, a galactic nucleus more than 13 billion light-years from Earth. These quasar observations provide a snapshot of our universe during its infancy, a mere 750 million years after the initial explosion that created the universe. Analysis of the quasar's light spectrum provided no evidence of heavy elements in the surrounding gaseous cloud—a finding that suggests the quasar dates to an era nearing that of the universe's first stars. "The first stars will form in different spots in the universe … it's not like they flashed on at the same time," says Robert Simcoe, an associate professor of physics at MIT. "But this is the time that it starts getting interesting."

 

Based on numerous theoretical models, most scientists agree on a general sequence of events during the universe's early development: Nearly 14 billion years ago, an immense explosion, now known as the Big Bang, threw off massive amounts of matter and energy, creating a rapidly expanding universe. In the minutes following the explosion, protons and neutrons collided in nuclear fusion reactions to form hydrogen and helium. Eventually, the universe cooled to a point where fusion stopped generating these basic elements, leaving hydrogen as the dominant constituent of the universe. Heavier elements, such as carbon and oxygen, would not form until the first stars appeared.


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Automated drug design using synthetic DNA self-assembly

Automated drug design using synthetic DNA self-assembly | Science Communication from mdashf | Scoop.it

Using a simple “drag-and-drop” computer interface and DNA self-assembly techniques, Parabon NanoLabs researchers have developed a new automated method of drug development that could reduce the time required to create and test medications, with the support of an NSF Technology Enhancement for Commercial Partnerships grant.


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Quantum mechanics on a planetary scale - Metallic hydrogen on Jupiter?

Quantum mechanics on a planetary scale - Metallic hydrogen on Jupiter? | Science Communication from mdashf | Scoop.it

HYDROGEN is the simplest and most abundant of elements. Composed of one proton and one electron, it makes up 90% of our universe (by number of atoms). On Earth, hydrogen is commonly found as a diatomic molecular gas. But on Jupiter, where interior pressure is millions of times greater than that at our planet's surface, the hydrogen molecule is theorized to exist as a superhot liquid metal. It’s under so much pressure that its protons and electrons are extremely closely confined, close to the limits imposed by the Pauli exclusion principle. Any closer, and two electrons would be forced into the same quantum state, which is forbidden. In this dense, high-pressure mix, the electrons of hydrogen atoms and their neighbors are so close together that it’s no longer clear which electron belongs to which proton. As well, electrons, having significantly less mass than protons, have higher average velocities. Momentum is the product of mass and velocity, so protons with the same momentum as electrons would move much slower. The electrons thus are free to move independently of their protons, and this hydrogen soup becomes a metal — a conductor of electricity, and a very good one at that! This also helps justify its place at the top of the alkali metal column in the periodic table.


The theory that hydrogen turns metallic under extreme pressure was first advanced in 1935 by Eugene Wigner, who would go on to win a 1963 Nobel Prize in physics for his work in quantum mechanics. Finding experimental evidence of Wigner's hydrogen metallization theory, however, has proven to be extremely difficult for the scientific community. While studies of the universe's lightest material led to discovery of hydrogen's solid and liquid phases, metallic hydrogen remained out of reach--until recently.


At Lawrence Livermore National Laboratory, in a series of shock compression experiments funded by Laboratory Directed Research and Development grants, we successfully ended a 60-year search for hard evidence of metallic hydrogen and the precise pressure at which metallization occurs at a particular temperature. The success in metallizing hydrogen would not have been achieved without the shock-wave technology built up over more than two decades to support Lawrence Livermore's nuclear weapons program. It represents the integration of the Laboratory's broad capabilities and expertise in gas-gun technology, shock physics, target diagnostics, hydrodynamic computational simulations, cryogenics, and hydrogen and condensed-matter physics.

 

 


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Birds may be dinosaurs that never grow up

Birds may be dinosaurs that never grow up | Science Communication from mdashf | Scoop.it

Modern day birds may simply be dinosaurs that never grew up druing development, researchers say.

 

Evolutionary biologist Arkhat Abzhanov of Harvard University noted an apparent resemblance between the skulls of juvenile dinosaurs and adult birds and decided to do a more comprehensive study. With graduate student Bhart-Anjan Bhullar, he used CT scanners to examine dozens of skulls, including modern birds, theropods -- the dinosaurs most closely related to birds -- and earlier dinosaur species. By identifying various landmarks on the skulls, they were able to track how the skull shapes had changed over the years.

 

"We examined skulls form the entire lineage that gave rise to modern birds," Abzhanov said. "We looked back approximately 250 million years, to the Archosaurs, the group which gave rise to crocodiles and alligators as well as modern birds. Our goal was to look at these skulls to see how they changed, and try to understand exactly what happened during the evolution of the bird skull."

 

What they found was surprising. Early dinosaurs underwent vast morphological changes as they aged. Among other things, their snouts grew longer and their heads grew flatter. The skulls of juvenile and adult birds, in contrast, are remarkably similar. They concluded that the evolutionary changes that produced birds were a phenomenon known as paedomorphosis. "We can see that the adults of a species look increasingly like the juveniles of their ancestors," Abzhanov said. In the case of birds, he added, the phenomenon is caused by a process called progenesis, in which the descendants reach sexual maturity earlier. Birds can take as little as 12 weeks to reach maturity, while dinosaurs required months or years. Concluded Abzhanov: "When we look at birds, we are actually looking at juvenile dinosaurs."


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How space-based solar power will solve all our energy needs

How space-based solar power will solve all our energy needs | Science Communication from mdashf | Scoop.it

Humanity's demand for energy is growing at an astonishing rate. Combine this with an ever-dwindling supply of fossil fuels, and it becomes painfully clear that something innovative and powerful is required. There's one high-tech proposal that holds tremendous promise — an idea that has been around since the late 1960s. Here's how space-based solar power will eventually solve all our energy needs.

 

Humans needs more power

 

Assuming that economic progress and globalization continues at its current pace, we'll need to produce twice the amount of energy that's consumed today by the 2030s — what will reach a monumental 220 trillion kiloWatt hours per year. And by the end of the century, we'll need four times the current rate of consumption.

 

Just as importantly, we're also going to have to kick the fossil fuel habit — and not only because it'll eventually run out. Rising CO2 emissions are wreaking havoc on the Earth's atmosphere, what's creating environmentally deleterious side-effects at a rate faster than expected.

Moreover, if greenhouse gases are to be brought under control over the course of the next several decades, we'll need to get upwards of 90% of all our energy from either renewable or nuclear sources.

While there are a number of proposals on the table for how we might be able to meet these challenges, none really appear to be truly viable.

Except for solar powered satellites.

 

Obvious benefits

 

A closer look at a space-based solution yields a lengthy list of advantages.

Solar powered satellites don't produce any greenhouse gases, nor do they take up valuable real estate on Earth. Once the initial costs are met, they would be relatively cheap to maintain; the solar modules used for generating solar energy have a long service life, not to mention the astounding ROI that would come from a virtually unlimited energy source.

Additionally, they're not constrained by night/day cycles, the weather, or the changing seasons. And indeed, they would be much more efficient than any kind of ground-based station. The collection of solar energy in space is seven times greater per unit area than on the surface of the planet. Moreover, the amount of solar energy available up there is staggering — on the order of billions of times greater than what we draw today; the Earth receives only one part in 2.3 billion of the Sun's output. The potential for scalability is enormous, to say the least.

Solar powered satellites won't be prone to terrorist attacks and they'll reduce geopolitical pressure for oil. According to futurist Keith Henson, space-based solar could be used to power vehicles, like electric cars, or by enabling the production of synthetic fuels — which at a penny per kiloWatt hour would result in gasoline that costs one dollar a gallon.

At the same time, space-based solar would provide true energy independence for those nations who choose to implement it. And on top of that, the energy could be exported to virtually anywhere in the world; it would be especially valuable for isolated areas of the globe, including Africa and India.

 

Lastly, space-based solar power would also yield tremendous benefits to human and robotic space exploration, including the powering of off-planet colonies on the Moon, Mars, and space stations. It could also serve as the first seed in the development of a Dyson Sphere — a massive array of solar collectors that would completely envelope the sun at a distance of about 1 AU.


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Krozen's curator insight, January 28, 2013 12:05 PM

A great idea, I'd say. Some kinks may have to be worked out, but it certainly has potential to push humanity ahead.

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Astrophysicists On The Verge Of Spotting Gravitational Waves

Astrophysicists On The Verge Of Spotting Gravitational Waves | Science Communication from mdashf | Scoop.it

Gravitational waves are ripples in the fabric of spacetime caused by cataclysmic events such as neutron stars colliding and black holes merging. The biggest of these events, and the easiest to see, are the collisions between supermassive black holes at the centre of galaxies. So an important question is how often these events occur.

 

Sean McWilliams and a couple of pals at Princeton University say that astrophysicists have severely underestimated the frequency of these upheavals. Their calculations suggest that galaxy mergers are an order of magnitude more frequent than had been thought. Consequently, collisions between supermassive black holes must be more common too. That has important implications for the ability of today's gravitational wave observatories to see them. There is an intense multi-million dollar race to be first to spot gravitational waves but if McWilliams and pals are correct the evidence may already be in the data collected by the first observatories. The evidence that McWilliams and co rely on is various measurements of galaxy size and mass. This data shows that in the last 6 billion years, galaxies have roughly doubled in mass and quintupled in size.

 

Astrophysicists know that there has been very little star formation in that time so the only way for galaxies to grow is by merging, an idea borne out by various computer simulations of the way that galaxies must evolve. These simulations suggest that galaxy mergers must be far more common than astronomers had thought.

 

That raises an interesting prospect--that the supermassive black holes at the centre of these galaxies must be colliding more often too. McWilliams and co calculate that black hole mergers must be between 10 and 30 times more common than expected and that the gravitational wave signals from these events are between 3 and 5 times stronger.

 

That has important implications for astronomers’ ability to see these signals. Astrophysicists are intensely interested in these waves since they offer an entirely new way to study the cosmos.


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Exoplanet Discoveries to Date Are Just a Drop in the Bucket - Systematic Searches Reveal Plenty Of Alien Worlds

Exoplanet Discoveries to Date Are Just a Drop in the Bucket - Systematic Searches Reveal Plenty Of Alien Worlds | Science Communication from mdashf | Scoop.it

Astronomers have in the past 20 years located several hundred planets orbiting distant stars, and they have only scratched the surface. In a small patch of stars—less than 1 percent of the sky—in the Northern Hemisphere, NASA's Kepler mission has already found more than 100 planets, along with strong hints of thousands more. Stars across the sky ought to be similarly laden with planets. A recent study indicated that each star hosts, on average, 1.6 planets. Exoplanets, as these strange worlds are called, are as plentiful as weeds—they crop up wherever they can. Whether any of them harbors life remains to be seen, but the odds of finding such a world are getting better.


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Keep European Science Competitive – Don’t Cut the European Research Council (ERC) Budget!

The Young Academy of Sweden has joined forces with the Young Academies of Germany, the Netherlands and Denmark to urge the leaders of the European Union to invest more, not less, in science in their upcoming budget (see go.nature.com/ymjole). Short-term savings would have long-term costs and weaken Europe's future scientific…

 

And by the way ... http://erc.europa.eu/

 


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