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AI can detect Alzheimer's years before symptoms show


The Week
Mon, 18 Sep 2017 00:01 UTC
AI brain scans to detect Alzheimer’s
© Dan Kitwood/Getty ImagesThe AI system uses brain scans to detect Alzheimer’s
The programme could help patients receive medication early to manage the disease.

Researchers have created an artificial intelligence (AI) programme that can detect signs of Alzheimer's disease up to ten years before symptoms appear.

Developed by a team at the University of Bari, in Italy, the computer system scans the brain for "tiny structural changes" that indicate the early stages of the disease, reports Engadget.

The AI was fed 38 MRI scans from Alzheimer's patients, and 29 from healthy patients, the website says, to help it learn common patterns in neurological activity and the symptoms of the disease.

Comment: See also: Researchers identify Alzheimer's tipping point: Excess glycation (i.e. too much sugar)



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Info

Doubt cast on what causes the northern lights


University of Alberta
Tue, 19 Sep 2017 06:45 UTC
Northern Lights
© David Phan, CC by 2.0UAlberta physicists have shown that the mechanism thought to be the cause of the northern lights fly in the face of what is has been commonly accepted in the world of space science.
What scientists thought caused certain classes of northern lights is not what causes certain classes of northern lights.

In a landmark study that has toppled what scientists know about the night sky, UAlberta physicists Robert Rankin and Dmytro Sydorenko found that the ionospheric feedback instability (IFI)-the mechanism thought to be the cause of certain types of northern lights-not only doesn't cause northern lights, it may not even exist at all.

"These findings fly in the face of what is now commonly accepted in the world of space science," said Rankin. "Our research shows that conditions necessary for the ionospheric feedback instability to occur are very unlikely, meaning it cannot be the cause of something as regular as the Aurora Borealis."
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Saturn

After 20 years, Cassini burns up in the skies over Saturn

Lisa Grossman
Science News
Fri, 15 Sep 2017 21:17 UTC
Cassini burning up above Saturn
© JPL Cal-Tech/NASACassini burned up like a comet above Saturn’s cloud tops just before 5 a.m. PDT on September 15. This artist’s illustration shows what it may have looked like.
After 20 years, nearly 300 orbits and pioneering discoveries, the spacecraft plunges to its death in Saturn's atmosphere

Cassini went down fighting.

After 20 years in space and 13 years orbiting Saturn, the veteran spacecraft spent its last 90 seconds or so firing its thrusters as hard as it could to keep sending Saturnian secrets back to Earth for as long as possible.

The spacecraft entered Saturn's atmosphere at about 3:31 a.m. PDT on September 15 and immediately began running through all of its stabilizing procedures to try to keep itself upright. The signal that Cassini had reached its destination arrived at Earth at 4:54 a.m., and cut out about a minute later as the spacecraft lost its battle with Saturn's atmosphere.

Comment: Rest in peace, Cassini.

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Sun

Solar paradox: New theory may explain why sun's biggest flares occur as a solar cycle ebbs

Lisa Grossman
Science News
Mon, 11 Sep 2017 20:30 UTC
sunspots 9.10.17
© SDO/GSFC/NASASPOT OF BOTHER The same complicated sunspot spat out seven flares from September 4 to 10. This image shows in ultraviolet light the second-largest flare (bright flash at right), which was emitted on September 10.
A series of rapid-fire solar flares is providing the first chance to test a new theory of why the sun releases its biggest outbursts when its activity is ramping down. Migrating bands of magnetism that meet at the sun's equator may cause the biggest flares, even as the sun is going to sleep.

A single complex sunspot called Active Region 2673 emitted seven bright flares - powerful bursts of radiation triggered by magnetic activity - from September 4 to September 10. Four were X-class solar flares, the most intense kind. The strongest, released at 8:02 a.m. EDT on September 6, was an X9.3. The most powerful flare since 2006 (and the eighth largest since monitoring started in June 1996), it disrupted shortwave radio communication over Africa for up to an hour. It also flung a blob of energetic plasma, called a coronal mass ejection, speeding toward Earth, which sparked auroras the night of September 7 that were visible as far south as Arkansas.

All that activity is counterintuitive, as the sun is near the end of an unusually weak solar cycle, which began in 2008 (SN: 11/2/13, p. 22). The sun's magnetic activity waxes and wanes roughly every 11 years, generating more dark sunspots at the peak of the cycle and fewer at the trough.
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Microscope 1

Researchers say miniscule DNA robots could soon end need for major surgeries


RT
Tue, 19 Sep 2017 12:39 UTC
two DNA robots sorting fluorescent molecules
© Demin Liu / California Institute of TechnologyA conceptual illustration of two DNA robots sorting fluorescent molecules
Robots made out of single strands of DNA could soon be used to precisely target and treat some of the world's deadliest diseases.

Developed by researchers from the California Institute of Technology, the microscopic machines have feet, arms and hands included in their design so they can maneuver and pick up molecules. They then recognize specific drop-off points and respond to signals telling them when to drop their cargo.
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Telescope

Darker than asphalt: Hubble telescope captures images of pitch-black exoplanet


Phys.org
Thu, 14 Sep 2017 00:00 UTC
Exoplanet WASO-12b
© NASA, ESA, and G. Bacon (STScI)This artist’s impression shows the exoplanet WASP-12b — an alien world as black as fresh asphalt, orbiting a star like our Sun. Scientists were able to measure its albedo: the amount of light the planet reflects. The results showed that the planet is extremely dark at optical wavelengths.
Astronomers have discovered that the well-studied exoplanet WASP-12b reflects almost no light, making it appear essentially pitch black. This discovery sheds new light on the atmospheric composition of the planet and also refutes previous hypotheses about WASP-12b's atmosphere. The results are also in stark contrast to observations of another similarly sized exoplanet.

Using the Space Telescope Imaging Spectrograph (STIS) on the NASA/ESA Hubble Space Telescope, an international team led by astronomers at McGill University, Canada, and the University of Exeter, UK, have measured how much light the exoplanet WASP-12b reflects-its albedo-in order to learn more about the composition of its atmosphere.

The results were surprising, explains lead author Taylor Bell, a Master's student in astronomy at McGill University who is affiliated with the Institute for Research on Exoplanets: "The measured albedo of WASP-12b is 0.064 at most. This is an extremely low value, making the planet darker than fresh asphalt!" This makes WASP-12b two times less reflective than our Moon which has an albedo of 0.12. Bell adds: "The low albedo shows we still have a lot to learn about WASP-12b and other similar exoplanets."
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Info

Humans lost ancient viral defense mechanism

Tine Danschutter, translated by Katrien Bollen
Katholieke Universiteit Leuven, Belgium
Fri, 15 Sep 2017 23:40 UTC
Sea anemone
© KU Leuven
Insects and plants have an important ancient defence mechanism that helps them to fight viruses. This is encoded in their DNA. Scientists have long assumed that vertebrates - including humans - also had this same mechanism. But researchers at KU Leuven have found that vertebrates lost this particular asset in the course of their evolution.

The possibilities encoded in our DNA are expressed via RNA. Conversely, RNA interference (RNAi) can also suppress the expression of a specific gene. Insects and plants use this RNAi mechanism to defend themselves against viruses, among other things. With a little help, insects and plants can even be made resistant to certain diseases through this RNAi mechanism. Examples include so-called genetically modified crops.

It seems only logical to assume, then, that humans can be protected against specific diseases in a similar way. However, past experiments to this effect have proven to be a challenge. Researchers from the Animal Physiology and Neurobiology unit at KU Leuven have now shown why this is the case.
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Info

Electric eels leap to deliver painful, taser-like shock

Kenneth Catania
Scienmag
Mon, 18 Sep 2017 19:50 UTC
Electric eels
The electric eel has always been noted for its impressive ability to shock and subdue its prey. It's recently become clear that electric eels also use a clever trick to deliver an intense, Taser-like jolt to potential predators: they leap from the water to target threatening animals, humans included, above water. Now, a researcher reporting in Current Biology on September 14 has measured (and experienced) just how strong that jolt can be.

Those stunning leaps make for a more painful experience because they prevent the eels' electrical discharges from weakening as they dissipate through the water.

"We've known these animals give off a huge amount of electricity, and everybody thought that was really amazing," says Kenneth Catania of Vanderbilt University. "But they aren't just simple animals that go around shocking stuff. They've evolved to produce stronger and stronger electrical discharges, and in concert they've evolved these behaviors to more efficiently use them."
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Seismograph

Superfast lightwaves can be slowed to store data on a computer chip - study


RT
Mon, 18 Sep 2017 17:14 UTC
Lightwaves
© Mehau Kulyk / Getty Images
Scientists have converted light-based information into sound waves on a computer chip in a world first - paving the way for the development of more efficient computers.

Researchers at the University of Sydney have published details of their groundbreaking study in Nature.

"It is like the difference between thunder and lightning," said Dr Birgit Stiller, supervisor of the project at the ARC Centre of Excellence for Ultrahigh bandwidth Devices for Optical Systems (CUDOS).

"The information in our chip in acoustic form travels at a velocity five orders of magnitude slower than in the optical domain," according to Stiller.

The delay allows for the data to be briefly stored and managed inside the chip for processing, retrieval and further transmission as light waves.
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Moon

Rare Moon 'occultation' is about to occur as it blocks view of three planets

Signe Dean
Science Alert
Mon, 18 Sep 2017 00:00 UTC
full moon
© Voraorn Ratanakorn/Shutterstock.com
On September 18, the Moon will pass in front of three planets and one of the brightest stars in our night sky, all in less than 24 hours, marking a special lunar occultation.

An occultation might sound like some creepy ritual, but it's actually just the term astronomers use to denote that one celestial body is blocking out another one in the sky. And as far as lunar occultations go, this one's a rare sight.

The Moon will be passing in front of Venus, then the first-magnitude star Regulus, then Mars, and finally Mercury. As the Moon orbits our planet, it regularly travels in front of other objects in the sky, but it's rare to get a planetary alignment quite like this one.

The last time we had a lunar occultation of three planets within a 24-hour window was on 5 March 2008 (Mercury, Venus, and Neptune), and it won't be until 2036 when we get another one with three planets.
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