Tag Archives: Technology

Closest Star System Found in a Century

WISE J104915.57-531906 is at the center of the larger image, which was taken by the NASA's Wide-field Infrared Survey Explorer (WISE). Image credit: NASA/JPL/Gemini Observatory/AURA/NSF

NASA’s Wide-field Infrared Survey Explorer (WISE) has discovered a pair of stars that has taken over the title for the third-closest star system to the sun. The duo is the closest star system discovered since 1916.

Both stars in the new binary system are “brown dwarfs,” which are stars that are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result, they are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the sun.

“The distance to this brown dwarf pair is 6.5 light-years — so close that Earth’s television transmissions from 2006 are now arriving there,” said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State University, University Park, Pa., and a researcher in Penn State’s Center for Exoplanets and Habitable Worlds.

 

“It will be an excellent hunting ground for planets because the system is very close to Earth, which makes it a lot easier to see any planets orbiting either of the brown dwarfs.”

The results will be published in the Astrophysical Journal Letters.

The star system is named “WISE J104915.57-531906″ because it was discovered in an infrared map of the entire sky obtained by WISE. It is only slightly farther away than the second-closest star, Barnard’s star, which was discovered 6 light-years from the sun in 1916. The closest star system consists of: Alpha Centauri, found to be a neighbor of the sun in 1839 at 4.4 light-years away, and the fainter Proxima Centauri, discovered in 1917 at 4.2 light-years.

Edward (Ned) Wright, the principal investigator for the WISE satellite at UCLA, said, “One major goal when proposing WISE was to find the closest stars to the sun. WISE J1049-5319 is by far the closest star found to date using the WISE data, and the close-up views of this binary system we can get with big telescopes like Gemini and the future James Webb Space Telescope will tell us a lot about the low-mass stars known as brown dwarfs.”

The Gemini South telescope in Chile was also used in this study for follow-up observations.

WISE completed its all-sky survey in 2011, after surveying the entire sky twice at infrared wavelengths. The maps have been released to the public, but an ongoing project called “AllWISE” will combine data from both sky scans. AllWISE will provide a systematic search across the sky for the nearby moving stars such as WISE J104915.57-531906, and also uncover fainter objects from the distant universe. Those data will be publicly available in late 2013.

The search for the truth behind Apple’s Lightning digital AV adapter

The search for the truth behind Apple’s Lightning digital AV adapter

Sending video from your phone or tablet to your TV is a very useful ability, and many options exist for doing so wirelessly – though most existing solutions are highly compressed and quite laggy. Obviously, a wired connection is what’s needed, right?

If you want a crisp 1080p signal from your iPhone or iPad, the best bet is to plug it in directly using Apple’s own £39 Lightning digital AV adapter. Unfortunately, it seems that this latest iteration of the device – designed to work with the new Lightning connector – isn’t putting out full 1080p.

Even worse, it seems that it is introducing noticeable compression artifacts (pictured below). Now comes the search for the truth amongst all of the Internet rage this is kicking up among Apple enthusiasts.

Cabel Sasser, a well-known software developer at Panic Inc., brought this issue to light at the end of last week. Through his own testing, he discovered that using the old Dock Connector AV adapter will output a full 1920 x 1080 video mirroring signal, but the newer Lightning AV adapter tops out at 1600 x 900.

After taking a hacksaw to the tiny adapter, it’s apparent that this isn’t just a simple cable. In fact, it has a minuscule ARM SoC and it is sporting upwards of 256MB of RAM. Cabel theorises that it is employing the same compression used in AirPlay to stream out the video, and that would explain the lag and artifacts being introduced to the signal. But why bother with this middleman at all? Well, we don’t have an official answer from Apple, but we have the next best thing: Wild conjecture and anonymous comments.

The Internet exploded with countless rage-posts about how Apple is screwing consumers. As cathartic as that may be, it didn’t provide much insight. Luckily, a comment on the original post provides interesting background to the ordeal. The anonymous commenter gives plenty of detail, and hints heavily that he or she is an Apple engineer. The commenter confirms that the SoC boots into Apple’s XNU kernel, but that’s as close as it gets to being iOS-like. Lightning isn’t capable of outputting an HDMI signal, so instead of adding complexity to each device, HDMI functionality was moved into the adapter.

According to this explanation, the iPhone uses the same hardware H.264 encoding that it would use to send video wirelessly over AirPlay. It then sends that compressed data out of the Lightning serial bus, and directly to the adapter. The SoC decodes the video, and handles the rest of the trip out to the end of the HDMI plug.

This accounts for all of the problems that Cabel ran into, and it seemingly has an understandable reason for existing in the first place. By having the iPhone spit a vanilla H.264 signal out of the Lightning connector, countless adapters can be made to work with existing phones instead of relying on the phone itself to support different specs (like HDMI itself). All of the heavy lifting is done by the adapter.

The quality is a problem, but updates are certainly a possibility if this commenter is to be believed. He or she even goes as far as to claim that iOS updates on the phone or tablet will be able to improve the quality of the output. At least it won’t require you to shell out for a whole new phone or £39 adapter. This isn’t a good excuse for the low quality output, but at least improvement seems inevitable and free of additional cost. Now we just have to wait for Apple to get round to making this better.

Computer Model May Help Athletes and Soldiers Avoid Brain Damage and Concussions

Concussions can occur in sports and in combat, but health experts do not know precisely which jolts, collisions and awkward head movements during these activities pose the greatest risks to the brain. To find out, Johns Hopkins engineers have developed a powerful new computer-based process that helps identify the dangerous conditions that lead to concussion-related brain injuries. This approach could lead to new medical treatment options and some sports rule changes to reduce brain trauma among players.

 

The research comes at a time when greater attention is being paid to assessing and preventing the head injuries sustained by both soldiers and athletes. Some kinds of head injuries are difficult to see with standard diagnostic imaging but can have serious long-term consequences. Concussions, once dismissed as a short-term nuisance, have more recently been linked to serious brain disorders.

“Concussion-related injuries can develop even when nothing has physically touched the head, and no damage is apparent on the skin,” said K. T. Ramesh, the Alonzo G. Decker Jr. Professor of Science and Engineering who led the research at Johns Hopkins. “Think about a soldier who is knocked down by the blast wave of an explosion, or a football player reeling after a major collision. The person may show some loss of cognitive function, but you may not immediately see anything in a CT-scan or MRI that tells you exactly where and how much damage has been done to the brain. You don’t know what happened to the brain, so how do you figure out how to treat the patient?”

To help doctors answer this question, Ramesh led a team that used a powerful technique called diffusion tensor imaging, together with a computer model of the head, to identify injured axons, which are tiny but important fibers that carry information from one brain cell to another. These axons are concentrated in a kind of brain tissue known as “white matter,” and they appear to be injured during the so-called mild traumatic brain injury associated with concussions. Ramesh’s team has shown that the axons are injured most easily by strong rotations of the head, and the researchers’ process can calculate which parts of the brain are most likely to be injured during a specific event.

The team described its new technique in the Jan. 8 edition of theJournal of Neurotrauma. The lead author, Rika M. Wright, played a major role in the research while completing her doctoral studies in Johns Hopkins’ Whiting School of Engineering, supervised by Ramesh. Wright is now a postdoctoral research fellow at Carnegie Mellon University. Ramesh is continuing to conduct research using the technique at Johns Hopkins with support from the National Institutes of Health.

Beyond its use in evaluating combat and sports-related injuries, the work could have wider applications, such as detecting axonal damage among patients who have received head injuries in vehicle accidents or serious falls. “This is the kind of injury that may take weeks to manifest,” Ramesh said. “By the time you assess the symptoms, it may be too late for some kinds of treatment to be helpful. But if you can tell right away what happened to the brain and where the injury is likely to have occurred, you may be able to get a crucial head-start on the treatment.”

Armed with this knowledge, Ramesh and his colleagues want to use their new technology to examine athletes, particularly football and hockey players, who are tackled or struck during games in ways that inflict that violent side-to-side motion on the head. In the recent journal article, the authors point out that many professional sports games are recorded in high-definition video from multiple angles. This, they write, could allow researchers to reconstruct the motions involved in sport collisions that lead to the most serious head injuries.

The authors also noted that some sports teams equip their players’ helmets or mouth guards with instruments that can measure the acceleration of the head during an impact. Such data, entered into the researchers’ computer model, could help determine the likely location of brain damage. These results, combined with neuropsychological tests, could be used to guide the athlete’s treatment and rehabilitation, the authors said, and to help a sports team decide when an athlete should be allowed to resume playing. This strategy also may help reduce the risk to athletes arising from a degenerative disease linked to repeated concussions.

More research, testing and validation must be conducted before the computer model can become useful in a clinical setting. This will include animal experiments and the correlation of data from event reconstruction to make sure the model accurately identifies brain injuries.

Ideally, Ramesh would like to collect digital brain images from soldiers and athletes before they enter combat or join highly physical sports activities. “We would then be able to track a high-risk population and keep records detailing what types of head injuries they experience,” he said. “Then, we could look at how their brains may have changed since the original images were collected. This will also help guide the physicians and health professionals who provide treatment after critical events.”

Scientists make mouse model of human cancer, demonstrate cure

Scientists report the first successful blocking of tumor development in a genetic mouse model of an incurable human cancer.

“To my knowledge, this is the first time that a mouse model of a genetically defined malignant human cancer has been generated in which the formation of the tumor from beginning to end can be monitored and in which blocking the pathway cures the mouse of the tumor,” said Dr. Luis Parada, chair of the department of developmental biology at UT Southwestern and senior author of the study published in Cell and online. The study’s first author is Dr. Wei Mo, a postdoctoral researcher in the department.

 

“We showed that blocking the activity of a receptor molecule named CXCR4 in these tumors – through genetic manipulation or by chemical blockade – inhibited tumor development. Together, these data reveal a potential target for therapy of these uncommon but currently untreatable malignant peripheral nerve sheath tumors (MPNSTs),” Dr. Parada added.

The study is a collaboration between Dr. Parada’s laboratory and that of Dr. Lu Q. Le, co-senior author of the study and assistant professor of dermatology. Dr. Le also is co-director of the adult Comprehensive Neurofibromatosis Clinic at UT Southwestern, the first such clinic in North Texas, which is part of the Simmons Comprehensive Cancer Center. The researchers noted that co-authors at The University of Texas MD Anderson Cancer Center and Baylor College of Medicine, Houston, greatly accelerated the research effort.

MPNSTs are rare but highly aggressive tumors that are resistant to therapy and are typically fatal. The malignancies can occur sporadically or in a subset of patients with a condition called neurofibromatosis 1 (NF1) – one of the most commonly inherited disorders of the nervous system, which affects an estimated 1 in 3,500 people.

The severity of NF1 can vary widely, even among family members, from mild dermatological symptoms to benign tumors that wrap around nerves and can be disfiguring, debilitating, and even life-threatening, depending on where they form, Dr. Le said. In addition, individuals with an improperly-functioning NF1 gene have an increased risk of developing cancerous tumors such as MPNSTs, he said.

The researchers generated a mouse model that spontaneously develops MPNSTs and compared gene expression activity in cancerous tumors and in the precursor cells that give rise to the tumors, which are the kind of cells in which MPNSTs develop.

They found that a protein (CXCR4), which is essential for tumor growth, is more abundant in cancerous cells than in precursor cells. In addition, they found that a molecule produced by the cancer cells themselves (CXCL12) works with CXCR4 to further the growth of cancer by stimulating the expression of the cyclin D1 protein, which promotes cell division via a signaling pathway outlined in the study.

When they examined human MPNSTs, the scientists found increased expression of CXCR4 accompanied by activity in the same pathway as the one identified in the mice, the researchers said.

Next, they blocked the activity of CXCR4 in the MPNST mice using either genetic manipulation or an FDA-approved antagonist drug for CXCR4 called AMD3100. Both strategies inhibited cancer development in mice whose tumors expressed increased levels of CXCR4, and were less effective in tumors without increased CXCR4 expression. They identified the same situation in the human cancer cells, the researchers report.

“We are very encouraged by these findings because they provide us with new directions and therapeutic windows to combat this deadly cancer, where none exist today,” said Dr. Le, who added that the researchers are currently planning human trials.

Building a better battery

A new battery technology provides double the energy storage at lower cost than the batteries that are used in handheld electronics, electric vehicles, aerospace and defence.

The batteries used in these applications are typically based on lithium and a metal oxide, such as cobalt, manganese or nickel. Researchers from the University of Cambridge have developed a composite of sulphur and nanostructured carbon, for use as a battery cathode with much higher energy storage at much lower cost than conventional materials.

 

The cathode, or positive electrode, is one of three functional components of a battery, along with the anode (negative electrode) and electrolyte. The raw cathode materials are the single largest material cost in battery production, representing between 35 and 40 per cent of total costs.

The global lithium-ion battery market is expected to expand to $54 billion by 2020, up from $11.8 billion in 2010, driven primarily by demand from the consumer electronics and electric vehicle sectors.

“Using sulphur instead of the materials currently used in lithium-ion batteries could substantially reduce production costs, as sulphur is a fraction of the cost of other materials,” says Dr Can Zhang of the Department of Engineering, one of the developers of the material. “Additionally, compared with conventional lithium-ion batteries, the carbon-sulphur electrodes achieve double the energy density per unit of weight.”

The carbon-sulphur electrodes are produced by growing a “forest” of high-quality carbon nanotubes (CNTs) on a layer of metal foam. The CNT forest provides excellent electrical conductivity, and acts as a three-dimensional scaffold into which the sulphur is injected in order to form the cathode.

The sulphur is trapped within the scaffold in the form of small particles which store electrons. The pore structure of the metal foam, combined with the dense vertical packing of CNTs, provides a labyrinth with a large surface area for the retention of electrode material.

Despite their higher density and lower costs, the commercial development of lithium-sulphur batteries has been largely plagued by short cycle life, typically below 80 charge-discharge cycles. In comparison, a conventional lithium-ion battery will usually achieve 500 charge-discharge cycles. The CNT-sulphur composite significantly enhances the cycle performance of lithium-sulphur batteries, retaining 80% capacity after over 250 full charge-discharge cycles.

The work is the result of a collaboration between the groups of Professor John Robertson of the Department of Engineering and Dr Vasant Kumar of the Department of Materials Science and Metallurgy.

Dr Zhang, a postdoctoral researcher in Professor Robertson’s group, has formed CamBattery to commercialise the technology, along with PhD students Bingan Chen, Kai Xi and Wentao He. The company won Technology Start-up of the Year at the 2012 Cambridge University Entrepreneurs competition.

Over the next two years, the team intends to build the first roll-to-roll machine to continuously produce the cathode material, and sell the product to major battery manufacturers. While the number of charge-discharge cycles achieved by lithium-sulphur batteries is not yet high enough for CamBattery to enter the consumer electronics market, applications in aerospace and defence are strong possibilities. “For aerospace and defence applications, energy storage takes precedence over life cycle,” says Dr Zhang. “However, we will continue working at getting the number of life cycles high enough for consumer electronics and electric vehicles.”

The Cambridge University Entrepreneurs (CUE) Business Creation Competition is the UK’s biggest student business plan competition. Since its creation in 2000, the competition has had more than 1,000 entries and awarded £500,000 in prize money to students and staff. Companies from the competition have gone on to raise close to £70 million in further funding.

Animated visualization maps a week’s worth of tweets sent between Twitter employees

Twitter interactions

The amount of publicly-available data available on Twitter, and a new data-visualization tool really hammers that home — developer Santiago Ortiz has mapped out the relationships between every Twitter employee based on their tweets to each other. Ortiz used Twitter’s API to pull all the tweets authored by Twitter employees for a one-week period, and then filtered those tweets by only those made between employees. The visualization Ortiz created is almost overwhelming in its depth of detail: hovering over a user’s avatar shows all the tweet-connections made by that person during the week, and clicking the avatar zooms in on that person and his or her contacts. Even more dramatically, you can click a “play” button to see a fast-forwarded view of every connection as it happened throughout the entire week — you can see small one-on-one coversations quickly branch to include more and more people. You can even click one user and drag to another to see a stream of any conversations the two individuals had.

While it feels slighly invasive and creepy, the simple fact is that none of these tweets are private — Ortiz only collected and collated this information into a more digestible form. As he told Fast Company DesignOrtiz took this challenge on simply to see if he could map a corporate hierarchy just using tweets, and figured that analyzing Twitter itself would be a good starting place. “The question is if this network matches the company structure…I believe yes, at least to some extent,” Ortiz said. Even after spending just a minute with Ortiz’ visualization, one thing is immediately obvious — Twitter employees certainly do like to use Twitter.

NASA Mission Helps Craft 3-D Image Of Buried Mars Flood Channels

This illustration schematically shows where the Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter detected flood channels that had been buried by lava flows in the Elysium Planitia region of Mars. Marte Vallis consists of multiple perched channels formed around streamlined islands. These channels feed a deeper and wider main channel. In this illustration, the surface has been elevated, and scaled by a factor of one to 100 for clarity. The color scale represents the elevation of the buried channels relative to a Martian datum, or reference elevation. The reason the values are negative is because the elevation of the surface of Mars in this region is also a negative -- below average global elevation.  Credit: NASA/JPL-Caltech/Sapienza University of Rome/Smithsonian Institution/USGS

SIllustration  shows where the Shallow Radar instrument detected flood channels that had been buried by lava flows in the Elysium Planitia region of Mars.

NASA’s Mars Reconnaissance Orbiter (MRO) has provided images allowing scientists for the first time to create a 3-D reconstruction of ancient water channels below the Martian surface.

The spacecraft took numerous images during the past few years that showed channels attributed to catastrophic flooding in the last 500 million years. Mars during this period had been considered cold and dry. These channels are essential to understanding the extent to which recent hydrologic activity prevailed during such arid conditions. They also help scientists determine whether the floods could have induced episodes of climate change.  The estimated size of the flooding appears to be comparable to the ancient mega flood that created the Channeled Scablands in the Pacific Northwest region of the United States in eastern Washington.


The findings are reported in the March 7 issue of Science Express by a team of scientists from NASA, the Smithsonian Institution, and the Southwest Research Institute in Houston.

“Our findings show the scale of erosion that created the channels previously was underestimated and the channel depth was at least twice that of previous approximations,” said Gareth Morgan, a geologist at the National Air and Space Museum’s Center for Earth and Planetary Studies in Washington and lead author on the paper. “This work demonstrates the importance of orbital sounding radar in understanding how water has shaped the surface of Mars.”

The channels lie in Elysium Planitia, an expanse of plains along the Martian equator and the youngest volcanic region on the planet. Extensive volcanism throughout the last several hundred million years covered most of the surface of Elysium Planitia, and this buried evidence of Mars’ older geologic history, including the source and most of the length of the 620-mile-long (1000-kilometer-long) Marte Vallis channel system. To probe the length, width and depth of these underground channels, the researchers used MRO’s Shallow Radar (SHARAD).

Marte Vallis’ morphology is similar to more ancient channel systems on Mars, especially those of the Chryse basin. Many scientists think the Chryse channels likely were formed by the catastrophic release of ground water, although others suggest lava can produce many of the same features. In comparison, little is known about Marte Vallis.

With the SHARAD radar, the team was able to map the buried channels in three dimensions with enough detail to see evidence suggesting two different phases of channel formation. One phase etched a series of smaller branching, or “anastomosing,” channels that are now on a raised “bench” next to the main channel. These smaller channels flowed around four streamlined islands. A second phase carved the deep, wide channels.

“In this region, the radar picked up multiple ‘reflectors,’ which are surfaces or boundaries that reflect radio waves, so it was possible to see multiple layers, ” said Lynn Carter, the paper’s co-author from NASA’s Goddard Space Flight Center in Greenbelt, Md. “We have rarely seen that in SHARAD data outside of the polar ice regions of Mars.”

The mapping also provided sufficient information to establish the floods that carved the channels originated from a now-buried portion of the Cerberus Fossae fracture system. The water could have accumulated in an underground reservoir and been released by tectonic or volcanic activity.

“While the radar was probing thick layers of dry, solid rock, it provided us with unique information about the recent history of water in a key region of Mars,” said co-author Jeffrey Plaut of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif.

The Italian Space Agency provided the SHARAD instrument on MRO and Sapienza University of Rome leads its operations. JPL manages MRO for NASA’s Science Mission Directorate in Washington. Lockheed Martin Space Systems of Denver built the orbiter and supports its operations.