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Galaxy

Scientists: Dark matter half what we thought

© Credit: ESO/L. Calçada
Artist’s impression of the Milky Way and its dark matter halo (shown in blue, but in reality invisible).
A new measurement of dark matter in the Milky Way has revealed there is half as much of the mysterious substance as previously thought.

Australian astronomers used a method developed almost 100 years ago to discover that the weight of dark matter in our own galaxy is 800 000 000 000 (or 8 x 1011) times the mass of the Sun.

They probed the edge of the Milky Way, looking closely, for the first time, at the fringes of the galaxy about 5 million billion kilometres from Earth.

Astrophysicist Dr Prajwal Kafle, from The University of Western Australia node of the International Centre for Radio Astronomy Research, said we have known for a while that most of the Universe is hidden.

"Stars, dust, you and me, all the things that we see, only make up about 4 per cent of the entire Universe," he said.

"About 25 per cent is dark matter and the rest is dark energy."
Comet

New fragmentation event in C/2011 J2 (LINEAR)

Starting from 2014, Sept 26.9 we are constantly monitoring comet C/2011 J2 (LINEAR) and his fragment B through a 2.0-m f/10.0 Ritchey-Chretien + CCD (La Palma-Liverpool Telescope). The video below shows an animation we made using our recent obs of this comet. Time span is 9 days (from 1 Oct. to 9 Oct). The projected velocity of the fragment is of about 0.3 arcsec/day.


While performing follow-up of component B of comet C/2011 J2 on 2014, Oct 09.9 we detected a possible new diffuse fragment located in the very near proximity of main component A.
Comet

'Duck and hide' - Comet's near-hit of Mars may crash NASA spacecraft orbiting planet

© Reuters/NASA
Comet Siding Spring is expected to travel exceptionally close to Mars at 126,000 mph (202,000 kph) on October 19, according to NASA, which says it will strategically maneuver its craft orbiting the Red Planet away from the comet's impacts.

Siding Spring will come within 87,000 miles (139,500 km) of Mars, which is "less than half the distance between Earth and our moon and less than one-tenth the distance of any known comet flyby of Earth,"NASA said.

NASA holdings that are orbiting and roving around Mars will collect data on the comet and its effects on the planet's atmosphere.
R2-D2

Man receives first prosthetic arm connected to bone, nerves & muscle that manages complicated tasks with the mind

© Youtube screenshot
The world's first amputee to receive a prosthetic arm directly connected to his bone, nerves and muscles has managed to perform highly complicated tasks, all with the power of his mind, a recent study has revealed.

The 42-year-old patient, identified only as Magnus, lost his right arm over a decade back. He was originally fitted with a prosthesis that was controlled via electrodes placed over the skin.

In 2013, an osseointegrated (bone-anchored) prosthetic arm was fitted onto Magnus by researchers at Chalmers University of Technology in Gothenburg. Results of the revolutionary surgery were recently outlined in the journal Science Translational Medicine.

"We have used osseointegration to create a long-term stable fusion between man and machine, where we have integrated them at different levels," said lead study author Max Ortiz Catalan, research scientist at Chalmers University of Technology, Sweden.

"The artificial arm is directly attached to the skeleton, thus providing mechanical stability. Then the human's biological control system, that is nerves and muscles, is also interfaced to the machine's control system via neuromuscular electrodes. This creates an intimate union between the body and the machine; between biology and mechatronics."
Bulb

Electrically charged graphene gives DNA a stage to perform molecular gymnastics

© Photo courtesy Alek Aksimentiev
DNA interacts with charged graphene and contorts into sequence-specific shapes when the charge is changed.
When Illinois researchers set out to investigate a method to control how DNA moves through a tiny sequencing device, they did not know they were about to witness a display of molecular gymnastics.

Fast, accurate and affordable DNA sequencing is the first step toward personalized medicine. Threading a DNA molecule through a tiny hole, called a nanopore, in a sheet of graphene allows researchers to read the DNA sequence; however, they have limited control over how fast the DNA moves through the pore. In a new study published in the journal Nature Communications, University of Illinois physics professor Aleksei Aksimentiev and graduate student Manish Shankla applied an electric charge to the graphene sheet, hoping that the DNA would react to the charge in a way that would let them control its movement down to each individual link, or nucleotide, in the DNA chain.

"Ideally, you would want to step the DNA through the nanopore one nucleotide at a time," said Aksimentiev. "Take a measurement and then have another nucleotide in the sensing hole. That's the goal, and it hasn't been realized yet. We show that, to some degree, we can control the process by charging the graphene."
Chalkboard

Quantum phase transitions occur near absolute zero temperature

theoreticale
© B.-J. Yang et al.
Figure 1: The critical point (red circle) between an insulator and the Weyl semimetal (SM) near absolute zero could provide a playground for unusual physics never seen before in conventional materials.
Naoto Nagaosa and Bohm-Jung Yang from the RIKEN Center for Emergent Matter Science and co-workers have discovered a previously unknown state of matter that can occur when matter switches from one exotic quantum state to another at temperatures near absolute zero.

Matter is conventionally classified as solid, liquid, gas or plasma depending on the interaction and organization of its atoms. Recently, however, scientists have identified novel 'quantum phases' of matter that occur at extremely low temperatures near absolute zero as a result of specific types of interactions among electrons that only occur at these low temperatures. Just as early physicists were intrigued by classical changes from one state to another with increasing temperature, such as a solid melting to a liquid or a liquid evaporating into a gas, today's researchers are now fascinated by changes between these exotic quantum phases brought about by quantum-level fluctuations known as quantum phase transitions.

Topological insulators are an example of an exotic quantum state in which the two-dimensional surface displays a protected conducting state that cannot be broken regardless of the nature of the surface, while the bulk of the material is insulating. However, it has been realized recently that topological phases can also occur in metallic systems.
R2-D2

'Bionic eye' gives blind man sight after 33 years

© Image from dukemedicine.org
A previously blind man from North Carolina has been granted the ability to digitally see once again through a new "bionic eye" which can transform light into images.

Larry Hester, 66, was blind for 33 years before scientists at Duke University, in North Carolina, switched on the device.

As the "eye" was switched on, Hester jumped from the shock initially, before his face broke into a persistent smile and his wife, Jerry, rushed over to him to share his joy. "Can you really see?" she said, adding: "Can I give him a kiss?"

Hester became only the seventh person in the US to have the eye - and he expressed his good fortune to his doctors.

"I just wonder how I have been so lucky," he said. "Why me? But if I can use what I learn from this to help others with RP, it will not just be for my benefit."

Both Larry and Jerry Hester had lost hope of any improvements in Larry's eyesight until Jerry found an article in a magazine last year.
Sherlock

Snowden says, 'Get rid of DropBox' and avoid Facebook

© Christopher Lane/AP Images for The New Yorker
Edward Snowden talks with Jane Mayer via satellite at the 15th Annual New Yorker Festival on Saturday, Oct. 11, 2014 in New York.
Edward Snowden has hit out at Dropbox and other services he says are "hostile to privacy," urging web users to abandon unencrypted communication and adjust privacy settings to prevent governments from spying on them in increasingly intrusive ways.

"We are no longer citizens, we no longer have leaders. We're subjects, and we have rulers," Snowden told The New Yorker magazine in a comprehensive hour-long interview.

There isn't enough investment into security research, into understanding how metadata could better be protected and why that is more necessary today than yesterday, he said.

The whistleblower believes one fallacy in how authorities view individual rights has to do with making the individual forsake those rights by default. Snowden's point is that the moment you are compelled to reveal that you have nothing to hide is when the right to privacy stops being a right - because you are effectively waiving that right.

"When you say, 'I have nothing to hide,' you're saying, 'I don't care about this right.' You're saying, 'I don't have this right, because I've got to the point where I have to justify it.' The way rights work is, the government has to justify its intrusion into your rights - you don't have to justify why you need freedom of speech."

In that situation, it becomes OK to live in a world where one is no longer interested in privacy as such - a world where Facebook, Google and Dropbox have become ubiquitous, and where there are virtually no safeguards against the wrongful use of the information one puts there.

Magic Wand

Scientists identify the signature of aging in the brain


Immunofluorescence microscope image of the choroid plexus. Epithelial cells are in green and chemokine proteins (CXCL10) are in red
How the brain ages is still largely an open question - in part because this organ is mostly insulated from direct contact with other systems in the body, including the blood and immune systems. In research that was recently published in Science, Weizmann Institute researchers Prof. Michal Schwartz of the Neurobiology Department and Dr. Ido Amit of Immunology Department found evidence of a unique "signature" that may be the "missing link" between cognitive decline and aging. The scientists believe that this discovery may lead, in the future, to treatments that can slow or reverse cognitive decline in older people.

Until a decade ago, scientific dogma held that the blood-brain barrier prevents the blood-borne immune cells from attacking and destroying brain tissue. Yet in a long series of studies, Schwartz's group had shown that the immune system actually plays an important role both in healing the brain after injury and in maintaining the brain's normal functioning. They have found that this brain-immune interaction occurs across a barrier that is actually a unique interface within the brain's territory.
Health

Ultraviolet light robot kills Ebola in two minutes on surfaces

While vaccine makers and drug companies are rushing to bring medical interventions to the market that might address the Ebola pandemic, there's already a technology available right now that can kill Ebola in just two minutes in hospitals, quarantine centers, commercial offices and even public schools.

It's called the Xenex Germ-Zapping Robot, and it was invented by a team of Texas doctors whose company is based on San Antonio. (And no, I didn't get paid to write this. I'm covering this because this technology appears to be a viable lifesaving invention.)

The Xenex Germ-Zapping Robot uses pulsed xenon-generated UV light to achieve what the company calls "the advanced environmental cleaning of healthcare facilities." Because ultraviolet light destroys the integrity of the RNA that viruses are made of, it renders viruses "dead." (Viruses aren't really alive in the first place, technically speaking, so the correct term is "nonviable.")

Ebola, just like most other viruses, are quickly destroyed by UV light. That's why Ebola likes to spread in dark places where sunlight doesn't reach. (Think of Ebola as a "vampire" virus that feeds off human blood but shuns sunlight...) The Xenex robot destroys Ebola on surfaces in just two minutes, zapping them with a specific wavelength of UV light at concentrations that are 25,000 times higher than natural sunlight.
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