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A noninvasive avenue for Parkinson’s disease gene therapy

A noninvasive avenue for Parkinson’s disease gene therapy | Amazing Science | Scoop.it

Nanoparticles bypass the blood-brain barrier to treat Parkinson's disease. 

Researchers at Northeastern University in Boston have developed a gene therapy approach that may one day stop Parkinson's disease (PD) in it tracks, preventing disease progression and reversing its symptoms. The novelty of the approach lies in the nasal route of administration and nanoparticles containing a gene capable of rescuing dying neurons in the brain. Parkinson's is a devastating neurodegenerative disorder caused by the death of dopamine neurons in a key motor area of the brain, the substantia nigra (SN). Loss of these neurons leads to the characteristic tremor and slowed movements of PD, which get increasingly worse with time. Currently, more than 1% of the population over age 60 has PD and approximately 60,000 Americans are newly diagnosed every year. The available drugs on the market for PD mimic or replace the lost dopamine but do not get to the heart of the problem, which is the progressive loss of the dopamine neurons.

 

The focus of Dr. Barbara Waszczak's lab at Northeastern University in Boston is to find a way to harvest the potential of glial cell line-derived neurotrophic factor (GDNF) as a treatment for PD. GDNF is a protein known to nourish dopamine neurons by activating survival and growth-promoting pathways inside the cells. Not surprisingly, GDNF is able to protect dopamine neurons from injury and restore the function of damaged and dying neurons in many animal models of PD. However, the action of GDNF is limited by its inability to cross the blood-brain barrier (BBB), thus requiring direct surgical injection into the brain. To circumvent this problem, Waszczak's lab is investigating intranasal delivery as a way to bypass the BBB. Their previous work showed that intranasal delivery of GDNF protects dopamine neurons from damage by the neurotoxin, 6-hydroxydopamine (6-OHDA), a standard rat model of PD.

 

Taking this work a step further, Brendan Harmon, working in Waszczak's lab, has adapted the intranasal approach so that cells in the brain can continuously produce GDNF. His work utilized nanoparticles, developed by Copernicus Therapeutics, Inc., which are able to transfect brain cells with an expression plasmid carrying the gene for GDNF (pGDNF). When given intranasally to rats, these pGDNF nanoparticles increase GDNF production throughout the brain for long periods, avoiding the need for frequent re-dosing. Now, in new research presented on April 20 at 12:30 pm during Experimental Biology 2013 in Boston, MA, Harmon reports that intranasal administration of Copernicus' pGDNF nanoparticles results in GDNF expression sufficient to protect SN dopamine neurons in the 6-OHDA model of PD.

 

Waszczak and Harmon believe that intranasal delivery of Copernicus' nanoparticles may provide an effective and non-invasive means of GDNF gene therapy for PD, and an avenue for transporting other gene therapy vectors to the brain. This work, which was funded in part by the Michael J. Fox Foundation for Parkinson's Research and Northeastern University, has the potential to greatly expand treatment options for PD and many other central nervous system disorders.

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Starlight spectra may reveal signature of life

Starlight spectra may reveal signature of life | Amazing Science | Scoop.it

Light spectrum from the atmospheres of two Earth-like planets could provide evidence of life, writes Rowan Philp. Two planets as friendly to life as the Earth have been found. Now, Harvard astronomers have told the Mail & Guardian that confirming the existence of life out there is just a matter of time, using an ingenious trick with starlight.

 

Just Google "solar spectrum", and you will see what "sunshine" really looks like under the proverbial microscope. The pair of dark shadows you will see in the burnt-yellow section of its rainbow, reflecting its strong sodium content, is our Sun's unique calling card.

 

The initial question for Kaltenegger and other astrobiologists was this: What would happen if that same bolt of light also passed through the atmosphere of an alien planet as it passed in front of its star before reaching our telescopes? Answer: More rainbow shadow lines. If she can find spectral lines for oxygen and methane, which a parent star itself does not have, she will have made a discovery on the scale of Hubble or Galileo.

 

Roughly 1000 extrasolar planets have so far been confirmed, but the vast majority are way too big or too hot for life to have a chance.

 

Until recently, the "signatures for life" technique was of little use, as most extrasolar planets were found because of wobbles in the orbits of their parent stars, tugged by the planet's gravity. 

 

Most that were found this way were many times bigger than Jupiter and stiflingly close to their stars. But the Kepler mission finds smaller, Earth-like planets by patiently waiting for one to pass across the face of a star, momentarily reducing its light. 

 

Kepler's alignment of star, planet and Earth puts this approach in pole position to make the find.

 

John Grunsfeld, the associate administrator for Nasa's science missions, said: "The Kepler spacecraft has certainly turned out to be a rock star of science. The discovery of these rocky planets in the habitable zone brings us a bit closer to finding a place like home. 

 

"It is only a matter of time before we know if the galaxy is home to a multitude of planets like Earth, or if we are a rarity."

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A new type of LED-powered streetlamp could radically reduce light pollution

A new type of LED-powered streetlamp could radically reduce light pollution | Amazing Science | Scoop.it

According to the researchers, conventional street lamps - which use high-pressure sodium or mercury vapour - scatter up to 20% of their energy horizontally or vertically because it is difficult to control their beams.

 

It is easier to direct light from LEDs because it is being emitted from a smaller area.

 

So, while manufacturers controlled the direction of the light rays from older lamps using a reflector typically made out of polished aluminium, they can now take advantage of lenses to be more precise.

 

The researchers say the best LED (light-emitting diode) streetlamps on the market direct about 10% of their energy horizontally or vertically.

 

But they claim their own invention could further reduce the amount to just 2%.Their proposed lamp uses three features to ensure the vast majority of its light is limited to a pre-determined rectangular shape covering the road:

• A special "total internal reflection" lens for each LED designed to focus its light's rays so that they travel parallel to each other in a single direction. This is rather than criss-crossing and diverging from each other causing many to spill beyond the target area.• A reflecting cavity into which the lens-covered LEDs are fitted. This helps "recycle" any light rays which fail to travel the desired path.• A diffuser through which the focused light passes to help tackle unwanted glare.

 

The researchers suggest that the set-up would also save on electricity costs since it should require between 10 and 50% less power to illuminate a section of road than current LED streetlamps.

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Nanowires grown on graphene have surprising structure

Nanowires grown on graphene have surprising structure | Amazing Science | Scoop.it

When a team of University of Illinois engineers set out to grow nanowires of a compound semiconductor on top of a sheet of graphene, they did not expect to discover a new paradigm of epitaxy.

The self-assembled wires have a core of one composition and an outer layer of another, a desired trait for many advanced electronics applications. Led by professor Xiuling Li, in collaboration with professors Eric Pop and Joseph Lyding, all professors of electrical and computer engineering.

 

Nanowires, tiny strings of semiconductor material, have great potential for applications in transistors, solar cells, lasers, sensors and more. "Nanowires are really the major building blocks of future nano-devices," said postdoctoral researcher Parsian Mohseni, first author of the study.


"Nanowires are components that can be used, based on what material you grow them out of, for any functional electronics application."


Li's group uses a method called van der Waals epitaxy to grow nanowires from the bottom up on a flat substrate of semiconductor materials, such as silicon. The nanowires are made of a class of materials called III-V (three-five), compound semiconductors that hold particular promise for applications involving light, such as solar cells or lasers.

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Male bowerbirds create forced perspective illusions that only females see

Male bowerbirds create forced perspective illusions that only females see | Amazing Science | Scoop.it

Right from its entrance, Disneyland is designed to cast an illusion upon its visitors. The first area – Main Street – seems to stretch for miles towards the towering castle in the distance. All of this relies on visual trickery. The castle’s upper bricks and the upper levels of Main Street’s buildings are much smaller than their ground-level counterparts, making everything seem taller. The buildings are also angled towards the castle, which makes Main Street seem longer, building the anticipation of guests.

 

These techniques are examples of forced perspective, a trick of the eye that makes objects seem bigger or smaller, further or closer than they actually are. These illusions were used by classical architects to make their buildings seem grander, by filmmakers to make humans look like hobbits, and byphotographers to create amusing shots. But humans aren’t the only animals to use forced perspective. In the forests of Australia, the male great bowerbird uses the same illusions to woo his mate.

 

Bowerbirds are relatives of crows and jays that live in Australian and New Guinea. To attract mates, males from each of the 20 or so species build an intricate structure called a bower, which he decorates with specially chosen objects. Some species favour blue trinkets; others collect a mishmash of flowers, fruits, insect shells and more. Surrounded by these knick-knacks, the artistic male performs an elaborate display; the female judges him on his skill as a performer, builder and decorator.

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Cause of LED Efficiency Droop Finally Revealed

Cause of LED Efficiency Droop Finally Revealed | Amazing Science | Scoop.it

Researchers at University of California, Santa Barbara, in collaboration with colleagues at the École Polytechnique in France, have conclusively identified Auger recombination as the mechanism that causes light emitting diodes (LEDs) to be less efficient at high drive currents. 

Until now, scientists had only theorized the cause behind the phenomenon known as LED “droop”—a mysterious drop in the light produced when a higher current is applied. The cost per lumen of LEDs has held the technology back as a viable replacement for incandescent bulbs for all-purpose commercial and residential lighting.

This could all change now that the cause of LED efficiency droop has been explained, according to researchers James Speck and Claude Weisbuch of the Center for Energy Efficient Materials at UCSB, an Energy Frontier Research Center sponsored by the U.S. Department of Energy. 

Knowledge gained from this study is expected to result in new ways to design LEDs that will have significantly higher light emission efficiencies. LEDs have enormous potential for providing long-lived high quality efficient sources of lighting for residential and commercial applications. The U.S. Department of Energy recently estimated that the widespread replacement of incandescent and fluorescent lights by LEDs in the U.S. could save electricity equal to the total output of fifty 1GW power plants. 

“Rising to this potential has been contingent upon solving the puzzle of LED efficiency droop,” commented Speck, professor of Materials and the Seoul Optodevice Chair in Solid State Lighting at UCSB. “These findings will enable us to design LEDs that minimize the non-radiative recombination and produce higher light output.”

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Rare galaxy found furiously turning gas into stars with almost 100% efficiency

Rare galaxy found furiously turning gas into stars with almost 100% efficiency | Amazing Science | Scoop.it

Astronomers have found a galaxy turning gas into stars with almost 100 percent efficiency, a rare phase of galaxy evolution that is the most extreme yet observed. The findings come from the IRAM Plateau de Bure interferometer in the French Alps, NASA's Wide-field Infrared Survey Explorer and NASA's Hubble Space Telescope.

"Galaxies burn gas like a car engine burns fuel. Most galaxies have fairly inefficient engines, meaning they form stars from their stellar fuel tanks far below the maximum theoretical rate," said Jim Geach of McGill University.

 

"This galaxy is like a highly tuned sports car, converting gas to stars at the most efficient rate thought to be possible," he said.

 

The galaxy, called SDSSJ1506+54, jumped out at the researchers when they looked at it using data from WISE's all-sky infrared survey. Infrared light is pouring out of the galaxy, equivalent to more than a thousand billion times the energy of our sun.

 

Hubble's visible-light observations revealed that the galaxy is extremely compact, with most of its light emanating from a region just a few hundred light-years across.

 

"This galaxy is forming stars at a rate hundreds of times faster than our Milky Way galaxy, but the sharp vision of Hubble revealed that the majority of the galaxy's starlight is being emitted by a region just a few percent of the diameter of the Milky Way. This is star formation at its most extreme," said Geach.

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Space collisions expected to rise dramatically during the next 200 years

Space collisions expected to rise dramatically during the next 200 years | Amazing Science | Scoop.it
Unless space debris is actively tackled, some satellite orbits will become extremely hazardous over the next 200 years, a new study suggests.

 

There are some 20,000 man-made objects in orbit that are currently being monitored regularly. About two-thirds of this population is in Low-Earth orbit.

 

These are just the big, easy-to-see items, however. Moving around unseen are an estimated 500,000 particles ranging in size between 1-10cm across, and perhaps tens of millions of other particles smaller than 1cm.

 

All of this material is travelling at several kilometres per second - sufficient velocity for even the smallest fragment to become a damaging projectile if it strikes an operational space mission.

 

Two key events have added significantly to the debris problem in recent years. The first was the destructive anti-satellite test conducted by the Chinese in 2007 on one of their own retired weather spacecraft. The other, in 2009, was the collision between the Cosmos 2251 and Iridium 33 satellites.

 

Taken together, these two events essentially negated all the mitigation gains that had been made over the previous 20 years to reduce junk production from spent rocket explosions.

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Igun Kuntaryo's comment, April 23, 2013 10:37 AM
the best
Jack Fox's comment, April 23, 2013 11:10 AM
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Whiteboxsynths's curator insight, April 24, 2013 1:30 PM

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Radioactively coated Listeria bacteria attack deadly pancreatic cancer

Radioactively coated Listeria bacteria attack deadly pancreatic cancer | Amazing Science | Scoop.it

Two dangerous things together might make a medicine for one of the hardest cancers to treat. In a mouse model of pancreatic cancer, researchers have shown that bacteria can deliver deadly radiation to tumours — exploiting the immune suppression that normally makes the disease so intractable. Fewer than one in 25 people diagnosed with pancreatic cancer are alive five years later. Chemotherapy, surgery and radiotherapy are generally ineffective, mainly because the disease has often spread to other organs even before it is detected.

 

The work, which is described in the Proceedings of the National Academy of Sciences, began when Ekaterina Dadachova of the Albert Einstein College of Medicine in New York thought of combining two ways to fight cancer. She studies how radioactive isotopes can be used as anti-cancer weapons, and her colleague Claudia Gravekamp has been looking at whether weakened bacteria can be used to carry compounds that provoke a patient’s white blood cells into attacking the cancer. “I thought maybe we could combine the power of radiation with the power of live bacteria,” Dadachova says.

 

Sometimes found in food, the bacterium Listeria monocytogenescan cause severe infection, but is usually wiped out by the immune system. Exploiting the fact that cancer cells tend to suppress the immune reaction to avoid being destroyed, the two researchers and their collaborators decided to coat Listeria with radioactive antibodies and injected the bacterium into mice with pancreatic cancer that had spread to multiple sites. After several doses, the mice that had received the radioactive bacteria had 90% fewer metastases compared with mice that had received saline or radiation alone. “That was the first time we'd seen such a big effect,” says Gravekamp.

 

Estimating dose levels between animals and humans is not always straightforward, but Dadachova counters that, according to her calculations, the radiation levels are below what is considered the safety threshold for humans, and that patients with pancreatic cancer tend to be less prone to radiation sickness because they have not usually received chemotherapy beforehand.

 

Joseph Herman, a radiation oncologist at Johns Hopkins, says that he would have liked to have seen results for other tumour types. And although the study found no signs of tissue damage one week after high-dose treatment of radioactive Listeria, Herman thinks that the effects of radiation might take longer to show up.

 

Still, Herman says, the approach might present an option where few exist. “The benefit is that it's a way of killing cancer cells in a cancer where therapy has not been very effective,” he says. “It's exciting, but it needs to be further validated.”

 

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Researchers Map the 3D Structure of the Telomerase Enzyme

Researchers Map the 3D Structure of the Telomerase Enzyme | Amazing Science | Scoop.it
Researchers from UCLA and UC Berkeley have, for the first time ever, solved the puzzle of how the various components of an entire telomerase enzyme complex fit together and function in a three-dimensional structure.

 

The telomerase enzyme, which is known to play a significant role in aging and most cancers, represents a breakthrough that could open up a host of new approaches to fighting disease.

 

The creation of the first complete visual map of thetelomerase enzyme, which is known to play a significant role in aging and most cancers, represents a breakthrough that could open up a host of new approaches to fighting disease, the researchers said.

"Everyone in the field wants to know what telomerase looks like, and there it was. I was so excited, I could hardly breathe," said Juli Feigon, a UCLA professor of chemistry and biochemistry and a senior author of the study. "We were the first to see it."

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WIRED: Bioengineers Build Open Source Language for Programming Cells

WIRED: Bioengineers Build Open Source Language for Programming Cells | Amazing Science | Scoop.it

Drew Endy wants to build a programming language for the body.

Endy is the co-director of the International Open Facility Advancing Biotechnology — BIOFAB, for short — where he’s part of a team that’s developing a language that will use genetic data to actually program biological cells. That may seem like the stuff of science fiction, but the project is already underway, and the team intends to open source the language, so that other scientists can use it and modify it and perfect it.

 

The effort is part of a sweeping movement to grab hold of our genetic data and directly improve the way our bodies behave — a process known as bioengineering. With the Supreme Court exploring whether genes can be patented, the bioengineering world is at crossroads, but scientists like Endy continue to push this technology forward.

 

Genes contain information that defines the way our cells function, and some parts of the genome express themselves in much the same way across different types of cells and organisms. This would allow Endy and his team to build a language scientists could use to carefully engineer gene expression – what they call “the layer between the genome and all the dynamic processes of life.”

 

The BIOFAB project is still in the early stages. Endy and the team are creating the most basic of building blocks — the “grammar” for the language. Their latest achievement, recently reported in the journalScience, has been to create a way of controlling and amplifying the signals sent from the genome to the cell. Endy compares this process to an old fashioned telegraph.

 

“If you want to send a telegraph from San Francisco to Los Angeles, the signals would get degraded along the wire,” he says. “At some point, you have to have a relay system that would detect the signals before they completely went to noise and then amplify them back up to keep sending them along their way.”

 

And, yes, the idea is to build a system that works across different types of cells. In the 90s, the computing world sought to create a common programming platform for building applications across disparate systems — a platform called the Java virtual machine. Endy hopes to duplicate the Java VM in the biological world.

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Last 30 years were the warmest in the last 1,400 years

Last 30 years were the warmest in the last 1,400 years | Amazing Science | Scoop.it

From 1971 to 2000, the world's land areas were the warmest they have been in at least 1,400 years, according to a new study inNature Geoscience. The massive new study, involving 80 researchers from around the world with the Past Global Changes (PAGES) group, is the first to look at continental temperature changes over two thousand years, providing insights into regional climatic changes from the Roman Empire to the modern day. According to the data, Earth's land masses were generally cooling until anthropogenic climate change reversed the long-term pattern in the late-19th Century.

"Even just a few years ago we would have aimed for a single worldwide temperature series," says co-author Ulf Büntgen with the Swiss Federal Research Institute (WSL) and PAGES. "Nowadays, we know how important it is to have a better understanding of regional differences."

Scientists were able to reconstruct continental temperatures across every continent except Africa, where data is still lacking. They found that continents could still show important idiosyncrasies even in the midst of global trends.

"Distinctive periods, such as the Medieval Warm Period or the Little Ice Age stand out, but do not show a globally uniform pattern," explains co-author Heinz Wanner with the University of Bern and a member of PAGES.

The researchers found that such temperature changes occurred during different times on continents. For example, the Medieval Warm Period occurred from around 830 to 1100 AD in the northern hemisphere, but a similar warm-up period doesn't show up in the southern hemisphere until 1160 to 1370 AD, a lag time of 300 years. Meanwhile, the Little Ice Age began decades earlier in the northern hemisphere than in the southern. The oddest continent proved to be Antarctica, which bucked trends elsewhere during several periods.

Looking at the temperature data over 30 years intervals allowed scientists to note that the most recent period (1971-2000) held the title for the warmest on record. Still, zooming into a continental view showed a slightly more diverse picture: for example, temperatures in Europe from 21-80 AD may rival those of 1971-2000. But globally the picture remains the same: over a thousand years of cooling, replaced suddenly by warming beginning in the late 19th Century. According to climatologists, temperatures have risen about 0.8 degrees Celsius (1.4 degrees Fahrenheit) in the last hundred years over land and sea due to burning fossil fuels, deforestation and other land-use changes, and industrial agriculture. The most recent decade was the hottest yet.

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3 newly discovered exoplanets could host life

3 newly discovered exoplanets could host life | Amazing Science | Scoop.it
Scientists discovered 3 planets in the "habitable zone" of their host stars. Kepler-69c seems less clearly in the habitable zone than the other two planets. They are all more than 1,000 light-years away. The Kepler satellite is looking at more than 150,000 stars for possible planets orbiting them.

Two of the planets -- Kepler-62e and Kepler-62f -- are described in a study released Thursday in the journal Science. They are part of a five-planet system in which the candidates for life are the farthest from the host star.

 

Their host star -- which corresponds to Earth's sun, but is smaller and cooler -- takes the name Kepler-62. The star's planets are designated by letters after the star's name. A third planet that's potentially habitable, but not included in the Science study, is called Kepler-69c.

 

These are the smallest planets ever found in the "habitable zone," the area near a star in which a planet can theoretically hold liquid water. Kepler-69c seems less clearly in the habitable zone than the other two planets, but scientists haven't ruled it out.

 

"With all of these discoveries we're finding, Earth is looking less and less like a special place and more like there's Earth-like things everywhere," said Thomas Barclay, Kepler scientist at the Bay Area Environmental Research Institute in Sonoma, California.

 

You won't be swimming on the planets anytime soon, though. The Kepler-62 star is 1,200 light-years away; Kepler-69 is 2,700 light-years away. A light-year, the distance that light travels in a vacuum in one year, is nearly 6 trillion miles.

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Breath analyzer brings roadside drug testing one step closer to reality

Breath analyzer brings roadside drug testing one step closer to reality | Amazing Science | Scoop.it
A group of researchers from Sweden have provided further evidence that illegal drugs can be detected in the breath, opening up the possibility of a roadside breathalyzer test to detect substances such as cocaine, amphetamines and cannabis.

 

Blood, urine and saliva are the most popular methods for detecting illegal drugs and are already used by law enforcement in a number of countries; however, exhaled breath is seen as a promising alternative as it's easier to collect, non-invasive, less prone to adulteration and advantageous when location becomes an obstacle, such as at the roadside.

 

Exhaled breath contains very small particles that carry non-volatile substances from the airway lining fluid. Any compound that has been inhaled, or is present in the blood, may contaminate this fluid and pass into the breath when the airways open. The compounds will then be exhaled and can subsequently be detected.

 

In this study, researchers from the Karolinska Institute in Stockholm collected breath, blood plasma and urine samples from 47 patients (38 males, 9 females) who had taken drugs in the previous 24 hours and were recovering at a drug addiction emergency clinic.

 

Interviews were also undertaken with each patient to assess their history of drug use. The breath samples were taken using a commercially available sampling device -- SensAbues -- and then analysed using liquid chromatography and mass spectrometry.

 

The portable sampling device consists of a mouth piece and a micro-particle filter. When a patient breathes into the mouth piece, saliva and larger particles are separated from the micro-particles that need to be measured.

 

The micro-particles are able to pass through and deposit onto a filter, which can then be sealed and stored ready for analysis. Breath samples were analysed for twelve substances.

 

Alprazolam and benzoylecgonine were detected in exhaled breath for the first time, whereas for methadone, amphetamine, methamphetamine, cocaine, morphine, 6-acetylmorphine, tetrahydrocannabinol, buprenorphine, diazepam and oxazepam, the results confirmed previous observations.

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Bizarre binary star system pushes study of relativity to new limits

Bizarre binary star system pushes study of relativity to new limits | Amazing Science | Scoop.it

A strange stellar pair nearly 7,000 light-years from Earth has provided physicists with a unique cosmic laboratory for studying the nature of gravity. The extremely strong gravity of a massive neutron star in orbit with a companion white dwarf star puts competing theories of gravity to a test more stringent than any available before.

 

Once again, Albert Einstein's General Theory of Relativity, published in 1915, comes out on top. At some point, however, scientists expect Einstein's model to be invalid under extreme conditions. General Relativity, for example, is incompatible with quantum theory. Physicists hope to find an alternate description of gravity that would eliminate that incompatibility.

 

A newly-discovered pulsar—a spinning neutron star with twice the mass of the Sun—and its white-dwarf companion, orbiting each other once every two and a half hours, has put gravitational theories to the most extreme test yet. Observations of the system, dubbed PSR J0348+0432, produced results consistent with the predictions of General Relativity.

 

The tightly-orbiting pair was discovered with the National Science Foundation's Green Bank Telescope (GBT), and subsequently studied in visible light with the Apache Point telescope in New Mexico, the Very Large Telescope in Chile, and the William Herschel Telescope in the Canary Islands. Extensive radio observations with the Arecibo telescope in Puerto Rico and the Effelsberg telescope in Germany yielded vital data on subtle changes in the pair's orbit.


In such a system, the orbits decay and gravitational waves are emitted, carrying energy from the system. By very precisely measuring the time of arrival of the pulsar's radio pulses over a long period of time, astronomers can determine the rate of decay and the amount of gravitational radiation emitted. The large mass of the neutron star in PSR J0348+0432, the closeness of its orbit with its companion, and the fact that the companion white dwarf is compact but not another neutron star, all make the system an unprecedented opportunity for testing alternative theories of gravity.

Under the extreme conditions of this system, some scientists thought that the equations of General Relativity might not accurately predict the amount of gravitational radiation emitted, and thus change the rate of orbital decay. Competing gravitational theories, they thought, might prove more accurate in this system.

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Earth's core far hotter than thought - 6,000 ˚C, as hot as sun surface

Earth's core far hotter than thought - 6,000 ˚C, as hot as sun surface | Amazing Science | Scoop.it

The solid iron core is actually crystalline, surrounded by liquid.

But the temperature at which that crystal can form had been a subject of long-running debate.

 

Experiments outlined in Science used X-rays to probe tiny samples of iron at extraordinary pressures to examine how the iron crystals form and melt.

Seismic waves captured after earthquakes around the globe can give a great deal of information as to the thickness and density of layers in the Earth, but they give no indication of temperature.

 

That has to be worked out either in computer models that simulate the Earth's insides, or in the laboratory. Measurements in the early 1990s of iron's "melting curves" - from which the core's temperature can be deduced - suggested a core temperature of about 5,000˚C.

 

"It was just the beginning of these kinds of measurements so they made a first estimate... to constrain the temperature inside the Earth," said Agnes Dewaele of the French research agency CEA and a co-author of the new research. 

 

"Other people made other measurements and calculations with computers and nothing was in agreement. It was not good for our field that we didn't agree with each other."

 

The core temperature is crucial to a number of disciplines that study regions of our planet's interior that will never be accessed directly - guiding our understanding of everything from earthquakes to the Earth's magnetic field.

 

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Biosciencia's curator insight, April 28, 2013 7:11 AM

New measurements suggest the Earth's inner core is far hotter than prior experiments suggested, putting it at 6,000C - as hot as the Sun's surface.

Florencia Araya's curator insight, October 28, 2013 8:02 AM

Image of how is the Earth Structure

Michelle Winemiller's curator insight, January 22, 2015 12:12 PM

great article since we just spoke about the fact due to the intense pressure that the core of Earth is as hot as the sun's surface--great reinforcement of material being covered

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Want to Have an Exoplanet Named After You?

Want to Have an Exoplanet Named After You? | Amazing Science | Scoop.it

Or perhaps you would like to name it “Tatooine” or “Wrigley’s Pleasure Planet”? If so, you are in luck–all you need to pay a small fee and keep voting. A startup company called Uwingu is holding a “people’s choice contest” to pick a name for the nearest planet outside our solar system. It orbits Alpha Centauri B, an orange star located just 4.3 light years from Earth, and currently has the ungainly name Alpha Centauri Bb. For $4.99 you can propose a name of your own, and for $0.99 you can vote on the winner. The contest runs until April 22; there is also a broader, ongoing campaign for other alien worlds.

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Jupiter's atmosphere still contains water supplied by the Shoemaker-Levy 9 impact

Jupiter's atmosphere still contains water supplied by the Shoemaker-Levy 9 impact | Amazing Science | Scoop.it

SL9 was discovered orbiting Jupiter by astronomers David Levy and Carolyn and Eugene M. Shoemaker on March 24, 1993. It was the first comet observed orbiting a planet rather than the Sun. SL9 was found to be composed of 21 fragments. Soon after that, orbital studies showed that the comet had passed within Jupiter's Roche limit in July 1992. Inside this limit, the planet's tidal forces are strong enough to disintegrate a body held together by its own gravity, thus explaining SL9's fragmentation. Even more interestingly, the studies showed that SL9's orbit would pass within Jupiter in July 1994 and that the comet would then collide with the planet, with impacts in the southern hemisphere near 44°S latitude.

 

The SL9 impact and its subsequent scars on Jupiter were observed for weeks, but its chemical impact on Jupiter's atmosphere lasted even longer. Emission from water vapor was observed during the fireball phase of the SL9 impacts, but from that observation, it was difficult to assess how this would modify Jupiter's composition on the long term. In 1997, the ESA Infrared Space Observatory (ISO) detected water vapor in the stratosphere of Jupiter. At that time, astronomers suspected that it might be a consequence of the SL9 impact because comets are known to be water-rich bodies. However, there were other possible sources of water: interplanetary dust particles produced by cometary activity and asteroid collisions, icy rings, or one of the 60 Jovian satellites.

 

Nearly twenty years after this major impact, astronomers are still observing its consequences on Jupiter. T. Cavalié and his colleagues observed Jupiter with the ESA Herschel Space Observatory, which is sensitive enough to map the abundance of water vs. latitude and altitude in the Jovian stratosphere.

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At least 1,000 Aboriginal founders first arrived from Asia some 50,000 years ago

At least 1,000 Aboriginal founders first arrived from Asia some 50,000 years ago | Amazing Science | Scoop.it

Indirect estimates based on carbon dating point to intentional settlement by a large population. At least 1,000 Aboriginal founders first arrived in Australia some 50,000 years ago, a reconstruction indicates — numbers that could be evidence of an intentional migration rather than the accidental stranding of a few individuals at a time. The study also finds that the population was devastated during the latest Ice Age, but later rebounded.


The prehistoric settlement of Australia has long been considered a simple story: a founding group of 150 people or fewer made it to the Australian mainland 50 millennia ago and grew to no more than 1.2 million by the time European settlers arrived in 1788. Debate focused on whether the founding population grew immediately after colonization or boomed later, in the past 5,000 years.

 

To tease out a demographic signal from the past, Alan Williams, an archaeologist at the Australian National University in Canberra, amassed the most comprehensive radiocarbon data set ever put together for the continent, from both published and unpublished sources. He analysed the dates of 4,575 artefacts from 1,750 archaeological sites.

 

Applying methods that others had developed to analyse a similar dataset from North American artifacts, Williams graphed the number of data points for each 200-year period, and made the assumption that for each given area, changes in the number of data points from one period to the next were a good indication of changes in population size — while correcting for the fact that some types of archaeological site can be lost over time owing to processes such as erosion. Assuming that the population would be between 750,000 and 1.2 million by the eighteenth century, he fit a smooth population curve to the data.

 

According to Williams' curve, 1,000–2,000 founders would be necessary to reach the population that was in place when the Europeans arrived. After the founders arrived, the population would have stabilized at low levels, but crashed during the most recent Ice Age, around 20,000 years ago. “To quantify the impacts of the last glacial maximum — and see a 60% reduction in population — is quite horrendous,” says Williams. After the Ice Age, population growth rates began to increase in pulses, starting 12,000 years ago.

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Lachlan Wilks's curator insight, November 10, 2013 5:36 PM

Helps with some research. Should read if doing the First Fleet or Contact history.

 

Taine Barker's curator insight, November 10, 2013 5:38 PM

This will be really good for history studies I would suggest you to read over.

James Miles's curator insight, November 10, 2013 6:09 PM

The origin of the Aboriginal people in Australia.

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3D Fractals in Motion: Meet the Animated Mandelbulb

3D Fractals in Motion: Meet the Animated Mandelbulb | Amazing Science | Scoop.it

In the world of fractals, the Mandelbrot Set is a stunning geometrical shape that results when you take a particular equation and apply it to a number, and then to the result, and then to each subsequent result after, ad infinitum. But what happens when you go from two dimensions to three? You get a “Mandelbulb.” And if you want to see how such a shape evolves over time, check out this stunning computer animation of a Mandelbulb modeling the movement of 250,000,000 particles.

Video of the Week #87, April 10th, 2013:

From: Meet the Mandelbulb by Jennifer Ouellette at Cocktail Party Physics.

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oliviersc's comment, April 23, 2013 12:48 PM
Trop long à charger ; Viméo rame...
jaber repon's curator insight, April 23, 2013 1:35 PM

tanku for<a hrfef=" http://monshaschoolandcollege.blogspot.com/"world </a>

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Grains of sand from ancient supernova found in meteorites

Grains of sand from ancient supernova found in meteorites | Amazing Science | Scoop.it

By looking at specks of dust carried to earth in meteorites, scientists are able to study stars that winked out of existence long before our solar system formed.

 

This technique for studying the stars – sometimes called astronomy in the lab — gives scientists information that cannot be obtained by the traditional techniques of astronomy, such as telescope observations or computer modeling.

 

Now scientists working at Washington University in St. Louis with support from the McDonnell Center for the Space Sciences, have discovered two tiny grains of silica (SiO2; the most common constituent of sand) in primitive meteorites. This discovery is surprising because silica is not one of the minerals expected to condense in stellar atmospheres — in fact, it has been called ‘a mythical condensate.’

 

Five silica grains were found earlier, but, because of their isotopic compositions, they are thought to originate from AGB stars, red giants that puff up to enormous sizes at the end of their lives and are stripped of most of their mass by powerful stellar winds.

 

These two grains are thought to have come instead from a core-collapse supernova, a massive star that exploded at the end of its life.

 

Because the grains, which were found in meteorites from two different bodies of origin, have spookily similar isotopic compositions, the scientists speculate in the May 1 issue of Astrophysical Journal Letters, that they may have come from a single supernova, perhaps even the one whose explosion is thought to have triggered the formation of the solar system.

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Escherichia coli bacteria produce diesel on demand

Escherichia coli bacteria produce diesel on demand | Amazing Science | Scoop.it

A team from the University of Exeter, with support from Shell, has developed a method to make bacteria produce diesel on demand. While the technology still faces many significant commercialisation challenges, the diesel, produced by special strains of E. coli bacteria, is almost identical to conventional diesel fuel and so does not need to be blended with petroleum products as is often required by biodiesels derived from plant oils. This also means that the diesel can be used with current supplies in existing infrastructure because engines, pipelines and tankers do not need to be modified. Biofuels with these characteristics are being termed 'drop-ins'.

Professor John Love from Biosciences at the University of Exeter said: "Producing a commercial biofuel that can be used without needing to modify vehicles has been the goal of this project from the outset. Replacing conventional diesel with a carbon neutral biofuel in commercial volumes would be a tremendous step towards meeting our target of an 80% reduction in greenhouse gas emissions by 2050. Global demand for energy is rising and a fuel that is independent of both global oil price fluctuations and political instability is an increasingly attractive prospect."

 

E. coli bacteria naturally turn sugars into fat to build their cell membranes. Synthetic fuel oil molecules can be created by harnessing this natural oil production process. Large scale manufacturing using E. coli as the catalyst is already commonplace in the pharmaceutical industry and, although the biodiesel is currently produced in tiny quantities in the laboratory, work will continue to see if this may be a viable commercial pathway to 'drop in' fuels.


Rob Lee from Shell Projects & Technology said: "We are proud of the work being done by Exeter in using advanced biotechnologies to create the specific hydrocarbon molecules that we know will continue to be in high demand in the future. While the technology still faces several hurdles to commercialisation, by exploring this new method of creating biofuel, along with other intelligent technologies, we hope they could help us to meet the challenges of limiting the rise in carbon dioxide emissions while responding to the growing global requirement for transport fuel."

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Antares rocket launch heats up private space race

Antares rocket launch heats up private space race | Amazing Science | Scoop.it

Watch out, SpaceX, there's a new commercial rocket in town. After a few delays due to weather and a technical glitch, the Antares launch vehicle lifted off on its maiden flight on 21 April, 2013. The launch sets the stage for a second company to begin resupply missions to the International Space Station.

 

Since the space shuttles retired in 2011, NASA has been contracting with private firms to deliver cargo – and soon hopefully astronauts – to the space station. California-based SpaceX became the first private firm to officially resupply the ISS last October. Its Falcon 9 rocket lifted off from Cape Canaveral in Florida carrying a Dragon capsule filled with cargo and science experiments.

 

Antares, built by spaceflight company Orbital Sciences of Dulles, Virginia, lifted off from the Mid-Atlantic Regional Spaceport on Wallops Island, Virginia, at 22.00 GMT.

 

Antares was designed to deliver the company's Cygnus cargo craft to the ISS. For the test flight, the rocket climbed high into a clear blue sky carrying a mock cargo ship with the same mass and dimensions as Cygnus, to avoid putting the real thing at risk.

 

About 10 minutes into the mission, the Cygnus dummy successfully separated from the rocket and went into a temporary orbit. It will fall back to Earth in about two weeks and disintegrate upon re-entering the atmosphere. The dummy contains instruments that will collect data about the launch, to be transmitted back to mission managers before re-entry.

 

When the real Cygnus flies, it will carry about 2 tonnes of cargo per trip. The Dragon capsule can deliver a payload of 3 tonnes. The two craft have comparable capabilities, claims Mark Pieczynski of Orbital Sciences. But while Dragon can return from its missions loaded with cargo, no Cygnus craft will ever make it back to Earth. These craft will leave the ISS filled with trash and will burn up in Earth's atmosphere.

 

Orbital's agreement with NASA includes this trial launch and a full demonstration mission in which the rocket will bring a real, loaded Cygnus craft to dock with the ISS, perhaps as early as June. If all goes well, the company is contracted to make a total of eight cargo missions to the station over the next three or four years.

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Fukushima Radiation Significantly Lower Than Expected, Study Says

Fukushima Radiation Significantly Lower Than Expected, Study Says | Amazing Science | Scoop.it

A new study on the radiation levels in Japanese locals after the Fukushima Daiichi nuclear power plant incident states that Cesium levels in the population are much lower than expected.

 

Based on studies from the Chernobyl incident in Russia in 1986, researchers anticipated that the levels of Cesium in those exposed to radiation after the meltdown at the Fukushima Daiichi campus to be equivalent with the deposition density, or the activity of a radioactive molecules in an area of ground, which is in Fukushima is reported measured at 2 millisieverts (mSv).

 

"Findings suggest that the level of internal radiation exposure brought about by pollution from the soil within the Fukushima Prefecture is much less than originally believed. The amount is so negligible that it is difficult to imagine there being any risk to the health," said Ryugo Hayano, a professor at Tokyo University's Science Research Department.

 

Fear of radiation exposure was rampant in many parts of Japan in the days and weeks after the Fukushima incident, which occurred March 11, 2011 after the largest earthquake in Japan's recorded history unleashed a tsunami that ravaged northeastern Japan's coastal communities and overcame the Daiichi reactors, causing the worst nuclear accident since Chernobyl.

 

Because more than two years have passed since the Fukushima incident, now the greatest risk from ongoing exposure to radioactive Cesium is through eating food grown in contaminated soil.

 

But of more than 100,000 people screened with whole-body scanners, the study showed 99.9 percent of them with a committed effective dose (CED) of less than 1 mSv. The safety standard and recommended maximum for artificial radiation exposure is 1 mSv.

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DARPA Looks To New Form Of Computation That Mimics The Human Brain

DARPA Looks To New Form Of Computation That Mimics The Human Brain | Amazing Science | Scoop.it

DARPA's Physical Intelligence program represents a potential major advance in artificial intelligence research, as the “physical intelligence” device would not require computer programming or the use of human controllers to provide directions, as with traditional robots. Instead, the device operates via nano-scale interconnected wires that send signals through synthetic synapses, just like the human brain. Such a system is capable of remembering information, meaning that robots might be able to act like humans in the foreseeable future.


Compared to traditional artificial intelligence systems that rely on conventional computer programming, this one “looks and ‘thinks’ like a human brain,” said James K. Gimzewski, professor of chemistry at the University of California, Los Angeles.

Gimsewski is a member of the team that has been working under sponsorship of the Defense Advanced Research Projects Agency (DARPA) on a program called Physical Intelligence.

The stated objective of the program is: "The analysis domain is to develop analytical tools to support the development of human-engineered physically intelligent systems and to understand physical intelligence in the natural world".

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Nacho Vega's curator insight, April 22, 2013 2:52 AM

DARPA has changed our world with Internet and now... Quantum computer

Helena Capela's curator insight, April 22, 2013 9:55 AM

We are closer to create artificial intelligence.Are we? A litle bit scary, no?

Marco Bertolini's curator insight, April 23, 2013 3:41 AM

Le Département américain de la défense étudie de nouveaux modes de calcul, basés sur le fonctionnement du cerveau.