The new method creates truly random numbers with less computational effort than other methods, which could facilitate significantly higher levels of security for everything from consumer credit card transactions to military communications.

Computer science professor David Zuckerman and graduate student Eshan Chattopadhyay will present research about their method in June at the annual Symposium on Theory of Computing (STOC), the Association for Computing Machinery's premier theoretical computer science conference. An invitation to present at the conference is based on a rigorous peer review process to evaluate the work's correctness and significance. Their paper will be one of three receiving the STOC Best Paper Award.

Chattopadhyay and Zuckerman publicly released a draft paper describing their method for making random numbers in an online forum last year (http://eccc.hpi-web.de/report/2015/119/). In a field more accustomed to small, incremental improvements, the computer science community hailed the method, suggesting that, compared with earlier methods, this one is light years ahead. Oded Goldreich, a professor of computer science at the Weizmann Institute of Science in Israel, commented that even if it had only been a moderate improvement over existing methods, it would have justified a "night-long party."

The new method takes two weakly random sequences of numbers and turns them into one sequence of truly random numbers. Weakly random sequences, such as air temperatures and stock market prices sampled over time, harbor predictable patterns. Truly random sequences have nothing predictable about them, like a coin toss.

The new research seems to defy that old adage in computer programming, "Garbage in, garbage out." In fact, it's the latest, most powerful addition to a class of methods that Zuckerman pioneered in the 1990s called randomness extractors.

Previous versions of randomness extractors were less practical because they either required that one of the two source sequences be truly random (which presents a chicken or the egg problem) or that both source sequences be close to truly random. This new method sidesteps both of those restrictions and allows the use of two sequences that are only weakly random.

An important application for random numbers is in generating keys for data encryption that are hard for hackers to crack. Data encryption is critical for making secure credit card purchases and bank transactions, keeping personal medical data private and shielding military communications from enemies, among many practical applications.

Zuckerman says that although there are already methods for producing high-quality random numbers, they are very computationally demanding. His method produces higher quality randomness with less effort.

Their paper shows how to generate only one truly random number -- akin to one coin toss -- but Zuckerman's former student Xin Li has already demonstrated how to expand it to create sequences of many more random numbers.

The website where Zuckerman and Chattopadhyay posted their draft last summer, called the Electronic Colloquium on Computational Complexity, allows researchers to share their work and receive feedback before publishing final versions in journals or at conferences. Computer scientists and mathematicians have been carefully reviewing the article, providing suggestions and even extending the method to make it more powerful.

A research group at Aalto University, Finland, propose a new theory of computer input explaining for example why serious gamers avoid touchscreens and why playing a piano on a touchscreen is so awkward.

"The common view before this work was that the lack of physical buttons is critical, but you also have tactile feedback from the surface of a touchscreen. Another false belief was that touchscreens are slower, but that is not the case anymore," Dr. Byungjoo Lee explains.

The group conducted experiments where participants were asked to tap a display when a target would appear. The data showed large differences between physical keys and touchscreens in how reliably users could time their presses.

"We found a systematic pattern in timing performance that we could capture mathematically," Dr. Lee tells.

The researchers proposed a new theory explaining that there are three sources of error that make timing very hard with touchscreens.

First, people are not able to keep the finger at a constant distance above the surface. The finger is always moving, and even the slightest movement hampers our ability to time precisely. By contrast, when using physical keys, the finger rests on the key, eliminating this source of error.

Second, when the finger touches the surface, it is hard for the neural system to predict when the input event has been registered. Typically software detects the touch when the finger first touches the display. But users cannot sense this event so it is not predictable for them.

Third, when the event has been registered on the touchscreen, it still needs to be processed in the application, and in some cases the time that it takes is longer than in other ones, creating another source of latency.

The new theory implies that users' performance can be improved by making touch events more predictable. The researchers showed that by registering the touch event when the finger's contact area on the surface is the maximum, timing performance can be improved significantly.

"Unfortunately, the theory also suggests that touchscreens may never be able to beat physical keys in gaming. The reason is that the finger travel distance varies and creates a source of unpredictability," reveals Professor Antti Oulasvirta.

In the final study, the researchers looked at Flappy Bird, a popular game requiring accurate timing.

"We can finally explain why games that require accurate timing are annoyingly hard on touchscreens. Our model can predict how many points a gamer is able to score in that game," Professor Oulasvirta concludes.

The paper will be presented at the CHI¹16 conference in San Jose in May 2016.

In a research researchers have found, "repeatedly playing violent video games reduces emotional responses like guilt."

Researchers from University at Buffalo, Michigan State University and University of California Santa Barbara in the US carried out a research in which they found that the moral response produced by the initial exposure to a video game decreases as experience with the game develops.

Rapidly advancing technology has created more realistic video games. These games are so real that gamers feel guilty committing unjustified acts of violence within the game. Reason of this is still unknown as said by Matthew Grizzard, from University at Buffalo.

It is often claimed by gamers their actions in a video game are meaningless to the real world. Researchers wanted to find the realibility of  this claim, whether virtual actions are actually responsible for desensitisation processes.

Although the findings suggest that desensitisation occurs, mechanisms underlying these findings are not entirely clear.

There are two arguments for the desensitisation effect, Grizzard said.

"One is that people are deadened because they've played these games over and over again. This makes the gamers less sensitive to all guilt-inducing stimuli," he said.

The second argument is a matter of tunnel vision.

"Gamers see video games differently than non-gamers, and this differential perception develops with repeated play," he said.

"Non-gamers look at a particular game and process all that's happening. For the non-gamer, the intensity of the scene trumps the strategies required to succeed," he said. "But gamers ignore much of the visual information in a scene as this information can be meaningless to their success in a game", according to Grizzard.

"This second argument says the desensitisation we're observing is not due to being numb to violence because of repeated play, but rather because the gamers' perception has adapted and started to see the game's violence differently," he said.

  

"Through repeated play, gamers may come to understand the artificiality of the environment and disregard the apparent reality provided by the game's graphics," Grizzard said.

The study was published in the journal Media Psychology.

The Indian space agency ISRO and US space agency NASA will join hands for the first time to launch a satellite that will help study earthquake and its patterns.

The satellite will be named NASA-ISRO Synthetic Aperture Radar, or NISAR. It is designed to observe and take measurements of some of the earth's most complex processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes and landslides.

NASA Administrator Charles Frank Bolden told they are planning to launch the satellite by 2020-21, but ISRO AS Kiran Kumar said they are looking to prepone the launch.

The project will not only help in understanding the seismic activity but also give inputs for monitoring agricultural activities in India, says ISRO AS Kiran Kumar.

"The US is providing L-Band. It will help us look at crustal deformation. We are looking for hints at earthquake detection. We cannot predict earthquake but we can advise people where it has occurred. We are hoping to launch it by 2020-21," Bolden told reporter.

"The activity involves building a payload with L- and S- bands synthetic aperture radar. It's a new technology instrument. While NASA provides the L-Band component of the electronics plus the antenna, which is a huge one. ISRO will provide the S-Band and the payload will be integrated at NASA and then the payload comes back at Bangalore. It gets integrated on the satellite, which is being built and will be launched by ISRO.

"So, currently the activities are going on in full swing. Both the governments have cleared the basic mission. We are looking at a possible launch with 2021. We are trying to advance the launch and we are working towards it. As far as we are concerned the usage of this got many significant usage for our programme," Kumar said.

"You can measure accurately the variations in surface topography, accuracy of millimeters. So, it's not earthquake prediction that is possible and making measurements of locations where large deformation are consistent, observation of changes in surface measures which will lead to stress levels being built up at certain locations which could help in understanding the behaviour of understanding earthquake and its phenomena. The objective is to make systematic study in timely manner," Kumar said.

"We are very much excited about it because for the first time two of our agencies are working together on such a big scale," the ISRO chief said, adding that both the space agencies have formed a working group and they would meet periodically.

"In future, we are also looking at what we could so with NASA in our future MARS missions. We are also looking at opportunities for some of our payloads which can be carried on their (NASA's) programmes. This is a continuous dialouge on how we can take forward our current engagements on Mars programme," Kumar said. 

They found that salts used in the liquid in the batteries make a big difference. When a salt called LiTFSI is packed in the liquid, a test battery can hold most of its charge for more than 200 uses. The LiTFSI helps bind up lithium atoms and sulfur on the electrode but quickly releases them. In contrast, a similar liquid ties up the lithium and sulfur but doesn't release it. The result is an electrode that quickly degrades; the battery fades after a few dozen uses.

One of the concerns with electric cars is long, lonely stretches of highway. Drivers don't want to be stranded between charging stations, and this concern can factor into their decision to buy lower emission vehicles. The results of this study add another important page into the design guide for high-energy lithium-sulfur batteries.

To determine the influence of electrolytes in lithium-sulfur batteries, the team did experiments with both LiTFSI and a similar electrolyte, called LiFSI, which has less carbon and fluoride. After continually measuring the amount of energy that the battery held and released, the team did a post-mortem analysis to study the electrodes. They did this work using instruments at DOE's EMSL, an Office of Science scientific user facility.

They discovered that with the LiTFSI, the electrode's lithium atoms became bound up with sulfur. The result is lithium sulfide (LiSx) forming on the electrode's surface. With LiFSI, lithium sulfate (LiSOx) formed. By calculating the strength with which the compounds clung to the lithium, they found that the lithium sulfide easily broke apart to release the lithium. However, the lithium sulfate was hard to separate. The oxygen in the lithium sulfate was the culprit.

"By conducting a macroscopic compositional analysis combined with simulations, we can see which bonds are easily broken and what will happen from there," said Dr. Ji-Guang (Jason) Zhang, who led the study at the national laboratory. "This process lets us identify the electrolytes behavior, guides us to design a better electrolyte, and improve the cycle life of lithium-sulfur batteries."

For the researchers, the next step is developing an electrolyte additive that forms a protective layer on the lithium anode's surface, protecting it from the electrolyte.

Tufts University biologists using a frog model have demonstrated for the first time that it is possible to prevent tumors from forming and normalize tumors after they have formed by using light to control electrical signaling among cells. The work, which appears online in Oncotarget on March 16, 2016 is the first reported use of optogenetics to specifically manipulate bioelectrical signals to both prevent and cause regression of tumors induced by oncogenes.

Frogs are a good model for basic science research into cancer because tumors in frogs and mammals share many of the same characteristics. These include rapid cell division, tissue disorganization, increased vascular growth, invasiveness and cells that have an abnormally positive internal electric voltage.

 

Virtually all healthy cells maintain a more negative voltage in the cell interior compared with the cell exterior; the opening and closing of ion channels in the cell membrane can cause the voltage to become more positive (depolarizing the cell) or more negative (polarizing the cell). Tumors can be detected by their abnormal bioelectrical signature before they are otherwise apparent.

"These electrical properties are not merely byproducts of oncogenic processes. They actively regulate the deviations of cells from their normal anatomical roles towards tumor growth and metastatic spread," said senior and corresponding author Michael Levin, Ph.D., who holds the Vannevar Bush chair in biology and directs the Center for Regenerative and Developmental Biology at Tufts School of Arts and Sciences. "Discovering new ways to specifically control this bioelectrical signaling could be an important path towards new biomedical approaches to cancer."

Lead author Brook Chernet, Ph.D., former post-doctoral associate in the Levin laboratory, injected cells in Xenopus laevis embryos with RNA encoding a mutant RAS oncogene known to cause cancer-like growths. The researchers also expressed and activated either a blue light-activated, positively charged ion channel, ChR2D156A, or a green light-activated proton pump, Archaerhodopsin (Arch), both of which hyperpolarize frog embryonic cells, thereby inducing an electric current that caused the cells to go from a cancer-like depolarized state to a normal, more negative polarized state. Activation of both agents significantly lowered the incidence of tumor formation and also increased the frequency with which tumors regressed into normal tissue.

The use of light to control ion channels has been a ground-breaking tool in research on the nervous system and brain, but optogenetics had not yet been applied to cancer.

"This provides proof of principle for a novel class of therapies which use light to override the action of oncogenic mutations," said Levin. "Using light to specifically target tumors would avoid subjecting the whole body to toxic chemotherapy or similar reagents."

Machine learning systems are everywhere. They predict the weather, forecast earthquakes, provide recommendations based on the books and movies we like, and even apply the brakes on our cars when we're not paying attention.

To do this, software programs in these systems calculate predictive relationships from massive amounts of data. The systems identify these predictive relationships using advanced algorithms -- a set of rules for solving math problems -- and "training data." This data is then used to construct the models and features that enable a system to determine the latest best-seller you wish to read or to predict the likelihood of rain next week.

This intricate process means that a piece of raw data often goes through a series of computations in a system. The computations and information derived by the system from that data together form a complex propagation network called the data's "lineage." The term was coined by Yinzhi Cao, an assistant professor of computer science and engineering, and his colleague, Junfeng Yang of Columbia University, who are pioneering a novel approach to make learning systems forget.

Considering how important this concept is to increasing security and protecting privacy, Cao and Yang believe that easy adoption of forgetting systems will be increasingly in demand. The two researchers have developed a way to do it faster and more effectively than can be done using current methods.

Their concept, called "machine unlearning," is so promising that Cao and Yang have been awarded a four-year, $1.2 million National Science Foundation grant to develop the approach.

"Effective forgetting systems must be able to let users specify the data to forget with different levels of granularity," said Cao, a principal investigator on the project. "These systems must remove the data and undo its effects so that all future operations run as if the data never existed."

Increasing security and privacy protection
There are a number of reasons why an individual user or service provider might want a system to forget data and its complete lineage. Privacy is one.

After Facebook changed its privacy policy, many users deleted their accounts and the associated data. The iCloud photo hacking incident in 2014 -- in which hundreds of celebrities' private photos were accessed via Apple's cloud services suite -- led to online articles teaching users how to completely delete iOS photos including the backups. New research has revealed that machine learning models for personalized medicine dosing leak patients' genetic markers. Only a small set of statistics on genetics and diseases are enough for hackers to identify specific individuals, despite cloaking mechanisms.

Naturally, users unhappy with these newfound risks want their data, and its influence on the models and statistics, to be completely forgotten.

Security is another reason. Consider anomaly-based intrusion detection systems used to detect malicious software. In order to positively identify an attack, the system must be taught to recognize normal system activity. Therefore the security of these systems hinges on the model of normal behaviors extracted from the training data. By polluting the training data, attackers pollute the model and compromise security. Once the polluted data is identified, the system must completely forget the data and its lineage in order to regain security.

Widely used learning systems such as Google Search are, for the most part, only able to forget a user's raw data -- and not the data's lineage -- upon request. This is problematic for users who wish to ensure that any trace of unwanted data is removed completely, and it is also a challenge for service providers who have strong incentives to fulfill data removal requests and retain customer trust.

Service providers will increasingly need to be able to remove data and its lineage completely to comply with laws governing user data privacy, such as the "right to be forgotten" ruling issued in 2014 by the European Union's top court. In October 2014, Google removed more than 170,000 links to comply with the ruling, which affirmed users' right to control what appears when their names are searched. In July 2015, Google said it had received more than a quarter-million such requests.

Breaking down dependencies

Building on work that was presented at a 2015 IEEE Symposium and then published, Cao and Yang's "machine unlearning" method is based on the fact that most learning systems can be converted into a form that can be updated incrementally without costly retraining from scratch.

Their approach introduces a layer of a small number of summations between the learning algorithm and the training data to eliminate dependency on each other. So, the learning algorithms depend only on the summations and not on individual data. Using this method, unlearning a piece of data and its lineage no longer requires rebuilding the models and features that predict relationships between pieces of data. Simply recomputing a small number of summations would remove the data and its lineage completely -- and much faster than through retraining the system from scratch.

Cao believes he and Yang are the first to establish the connection between unlearning and the summation form.

And, it works. Cao and Yang tested their unlearning approach on four diverse, real-world systems: LensKit, an open-source recommendation system; Zozzle, a closed-source JavaScript malware detector; an open-source OSN spam filter; and PJScan, an open-source PDF malware detector.

The success of these initial evaluations has set the stage for the next phases of the project, which include adapting the technique to other systems and creating verifiable machine unlearning to statistically test whether unlearning has indeed repaired a system or completely wiped out unwanted data.

In their paper's introduction, Cao and Yang say that "machine unlearning" could play a key role in enhancing security and privacy and in our economic future:

"We foresee easy adoption of forgetting systems because they benefit both users and service providers. With the flexibility to request that systems forget data, users have more control over their data, so they are more willing to share data with the systems. More data also benefit the service providers, because they have more profit opportunities and fewer legal risks.

"We envision forgetting systems playing a crucial role in emerging data markets where users trade data for money, services, or other data because the mechanism of forgetting enables a user to cleanly cancel a data transaction or rent out the use rights of her data without giving up the ownership." 

Nobody wants a laptop computer that stops working when a cloud passes by. Storing sunlight as fuel that can be later used to drive fuel cells requires new materials. Scientists demonstrated such a material. They combined two oxides on the atomic scale. The interface between the oxide materials, one containing strontium and titanium and one containing lanthanum and chromium, absorbs visible light, producing electrons and holes that might be useful for catalyzing reactions, such as producing hydrogen fuel. 

 

However, if there is nothing to pull those electrons and holes apart, they will quickly annihilate one another without doing anything useful. By carefully synthesizing this material as a series of alternating layers, the international team created a built-in electric field that could help separate the excited electrons and holes and improve the material's performance as a catalyst.

This material opens up new scientific frontiers to solve a persistent energy challenge: storing solar energy for later use. Fuel cells capable of running on hydrogen fuel created by solar energy could allow people to heat their homes and run their computers on solar energy even in the dark of night.

By depositing thin layers of SrTiO3 and LaCrO3 on a crystalline substrate, the investigators at the Pacific Northwest National Laboratory, Argonne National Laboratory, SuperSTEM, and the University of Oxford controlled how the ions at the interfaces bond to each other. This allowed them to engineer an electric field in the material that can be used to separate electrons and holes. Using X-ray spectroscopy techniques, they confirmed that the electric field was present and that the ions in the material shift positions as a result. Ultra-high resolution measurements using an electron microscope helped confirm this ionic shift.

All of these experimental results were backed up by computational modeling of the materials, which predicted behavior in excellent agreement with what was observed.

The electric field in these materials is present because the researchers were able to precisely control the growth process so that each interface has either a positive or negative charge. Alternating positively and negatively charged interfaces in the material produce nanoscale electric fields that can interact with the electrons and holes that are excited by solar energy. 

Electrons may then be driven to the surface, where they could interact with water molecules to break their bonds and produce hydrogen fuel.

Researchers are continuing to explore the properties of these superlattices using cutting-edge X-ray measurements at synchrotrons around the world and using other advanced microscopy techniques to look at the chemical makeup of the interfaces.

Facebook said it has paid Rs 4.84 crore to security researchers in India as part of its bug bounty programme, the most paid till date by the world's largest social networking platform. 

India, which has over 142 million Facebook users, also holds top rank among 127 countries in terms of researchers contributing to its bug bounty programme, it said in a blog.

"India is home to the largest population of security researchers (205) participating in the Facebook bug bounty programme since its inception in 2011. The country also holds the top spot for most bounties paid (Rs 48.4 million)," Adam Ruddermann, a technical program manager on the Facebook Bug Bounty team, wrote.

Facebook's bug bounty programme has received over 2,400 valid submissions and has awarded more than $4.3 million to 800-plus researchers globally.

Under the programme, researchers get rewarded for reporting security bugs, identifying vulnerabilities in Facebook's services or infrastructure that can create security or privacy risks.

In 2015, Facebook's team classified 102 bug bounty submissions as high impact, an increase of 38 per cent over the previous year.

It received 13,233 total submissions from 5,543 researchers in 127 countries and paid $936,000 to 210 researchers, who submitted a total of 526 valid reports.

The average payout was $1,780. India, Egypt, and Trinidad and Tobago received the highest number of payouts.

"Facebook receives more and more high-impact bugs (related reports) from India each year, reflecting the growing sophistication and technical capabilities of the country's engineering schools and cybersecurity programmes," he said.

Explaining how Facebook calculated the risk and bounties paid to researchers, Ruddermann said the company looks at the potential impact of a bug, what could possibly go wrong, and who would be affected.

"The primary goal of our programme is to protect the people who use Facebook, so bugs that impact end users are the most important to us. We also consider the difficulty of exploiting the vulnerability and what kind of resources or technical skills a successful attack would require," he added.

The amount paid in bounties is generally consistent but can change as the risk landscape evolves, he said.

"We also reserve the option to award researchers more than the base amount if the report itself exhibits a high level of clarity, sophistication, and detail," Ruddermann said.

A recent episode of "Top Chef" challenged contestants to create picture-perfect dishes using junk food. Unlike their typical challenges, these creations were judged not on the basis of taste or innovation, but solely by presentation -- on Instagram.


The winner was determined by the highest number of "likes."

While the contest may seem odd, photography has become a large part of the dining experience. Food-related hashtags on social media have millions of posts and most Americans don't flinch at the sight of fellow diners snapping photos of their meals.

Intrigued by this new social norm and its impact, Sean Coary, Ph.D., assistant professor of food marketing at Saint Joseph's University in Philadelphia, teamed up with Morgan Poor, Ph.D., assistant professor of marketing at the University of San Diego, to research the impact of consumer-generated images of food on satisfaction.

"When we take a photo of something before eating, we create a momentary but intentional delay in consumption, allowing all of the senses to be engaged and building the anticipation of enjoyment," says Coary.

Coary and Poor's research, published in the Journal of Consumer Marketingthis past January, included three studies with over 120 participants in each study. Results suggest that taking a picture before consumption leads to more favorable evaluations of the food -- but only when the dish is indulgent in nature. However, according to Coary and Poor, the positive effects of photographing food can be activated when consumers are aware of the healthy eating habits of others.

"Diners want to remember the visual aesthetic of their food, especially when it's something indulgent," says Coary. On the other hand, "when eating healthy, there's a desire to signal to others that we are part of the 'fit' club." In either scenario, Coary says it's a way to participate in a widely accepted communal practice.

 In addition to sparking ideas for future research, these studies have implications for food brands and restaurants, according to Poor. Of this amateur food-photographer phenomenon, she predicts "this is only the beginning."

Poor and Coary encourage more restaurants and food brands to embrace it -- and capitalize on their customer's eagerness to take and share images.

"If your food is beautiful and aesthetically pleasing, your customers will want to take a photograph and potentially share it," adds Coary. "Training staff who understand the importance of aesthetics and finding creative ways to take advantage of this free advertising are crucial for both brands and restaurants"

Deepika Raj and Jung E Ha-Brookshire of the University of Missouri interviewed people employed in the WT industry -- with its unique collaboration between apparel and technology specialists -- to find out how creating the devices changed the way they worked. They also wanted to find out what the designers themselves thought of the items they were creating.

As Raj and Ha-Brookshire explain: "Despite the significance and popularity of WT in today's market environment, little research has been done to understand what WT employees think about WT when developing new products. We also know little about the knowledge-creation processes that WT employees may go through to develop innovative WT products and specific work environments that are ideal for WT innovation.

Perhaps unsurprisingly, the respondents were very positive about the benefits of WT. Replies like 'it makes you do more with less', 'creates fun and meaningful solutions to everyday problems' and 'solves multiple problems' were common.

The notion of WT giving people superpowers also cropped up repeatedly. "For the less-able bodied, [one of the respondents] believed WT could help them hear, see, or speak better. For able-bodied people … WT could help them do things they could not do before," the authors note. "In both cases, WT gave a sort of superpower to human beings."

The workers were also clear on what made good WT: it had to be easy to use, 'fit the curve of the body', improve connectivity with the outside world and, ideally, solve problems for the user.

Perhaps fittingly, working on WT also changed the way the WT specialists themselves worked. As good WT needs to draw on different knowledge bases, the workers found themselves collaborating more and understanding better both the terms and working practices of other disciplines. "New knowledge was created within WT firms through the process of socialisation by personal communications, internalisation and by trial and error," the authors observe. And just as WT can empower its users, 'innovation in WT firms seems to be possible by empowering the work force and giving them a productive atmosphere to foster creativity and collaborations.'

Certainly for the WT workers themselves, it would appear that WT can change lives in more ways than one.

A recent observational campaign involving more than two dozen optical telescopes and NASA's space based SWIFT X-ray telescope allowed a team of astronomers to measure very accurately the rotational rate of one of the most massive black holes in the universe. The rotational rate of this massive black hole is one third of the maximum spin rate allowed in General Relativity. This 18 billion solar mass heavy black hole powers a quasar called OJ287 which lies about 3.5 billion light years away from Earth. Quasi-stellar radio sources or `quasars' for short, are the very bright centers of distant galaxies which emit huge amounts of electro-mag

netic radiation due to the infall of matter into their massive black holes.

This quasar lies very close to the apparent path of the Sun's motion on the celestial sphere as seen from Earth, where most searches for asteroids and comets are conducted. Therefore, its optical photometric measurements already cover more than 100 years. A careful analysis of these observations show that OJ 287 has produced quasi-periodic optical outbursts at intervals of approximately 12 years dating back to around 1891. Additionally, a close inspection of newer data sets reveals the presence of double-peaks in these outbursts.

These deductions prompted Prof. Mauri Valtonen of University of Turku, Finland and his collaborators to develop a model that requires the quasar OJ287 to harbour two unequal mass black holes. Their model involves a massive black hole with an accretion disk (a disk of interstellar material formed by matter falling into objects like black holes) while the comparatively smaller black hole revolves around it. The quasar OJ287 is visible due to the slow accretion of matter, present in the accretion disk, onto the largest black hole. Additionally, the small black hole passes through the accretion disk during its orbit which causes the disk material to heat up to very high temperatures. This heated material flows out from both sides of the accretion disk and radiates strongly for weeks. This causes peaks in the brightness, and the double peaks arise due to the ellipticity of the orbit, as shown in the figure.

The binary black hole model for OJ287 implies that the smaller black hole's orbit should rotate, and this changes where and when the smaller hole impacts the accretion disk. This effect arises from Einstein's General Theory of Relativity and its precessional rate depends mainly on the two black hole masses and the rotation rate of the more massive black hole. In 2010, Valtonen and collaborators used eight well timed bright outbursts of OJ287 to accurately measure the precession rate of the smaller hole's orbit. This analysis revealed for the first time the rotation rate of the massive black hole along with accurate estimates for the masses of the two black holes. This was possible since the smaller black hole's orbit precess at an incredible 39 degrees per individual orbit. The General Relativistic model for OJ287 also predicted that the next outburst could occur around the time of GR Centenary, 25 November 2015, which marks the 100th anniversary of Einstein's General Theory of Relativity.

An observational campaign was therefore launched to catch this predicted outburst. The predicted optical flare began around November 18, 2015 and reached its maximum brightness on December 4, 2015. It is the timing of this bright outburst that allowed Valtonen and his co-workers to directly measure the rotation rate of the more massive black hole to be one third of the maximum spin rate allowed in General Relativity. In other words, its Kerr parameter is accurately measured to be 0.31 and its maximum allowed value in General Relativity is one. In comparison, the Kerr parameter of the final black hole associated with the first ever direct detection of gravitational waves is only estimated to be below 0.7.

The observations leading to accurate spin measurement have been made due to the collaboration of a number of optical telescopes in Japan, South Korea, India, Turkey, Greece, Finland, Poland, Germany, UK, Spain, USA and Mexico. The effort, led by Staszek Zola of Poland, involved close to 100 astronomers from these countries. Interestingly, a number of key participants were amateur astronomers who operate their own telescopes. Valtonen's team that developed and contributed to the spinning binary black hole model include theoretical astrophysicist A. Gopakumar from TIFR, India, and Italian X-Ray astronomer Stefano Ciprini who obtained and analyzed the X-ray data.

The occurrence of the predicted optical outburst of OJ287 also allowed the team to confirm the loss of orbital energy to gravitational waves within two percent of General Relativity's prediction. This provides the first indirect evidence for the existence of a massive spinning black hole binary emitting gravitational waves. This is encouraging news for the Pulsar Timing Array efforts that will directly detect gravitational waves from such systems in the near future. Therefore, the present optical outburst of OJ287 makes a fitting contribution to the centenary celebrations of General Relativity and adds to the excitement of the first direct observation of a transient gravitational wave signal by LIGO.

The foldable object that was created by researchers

Imagine a house that could fit in a backpack or a wall that could become a window with the flick of a switch.

Harvard researchers have designed a new type of foldable material that is versatile, tunable and self actuated. It can change size, volume and shape; it can fold flat to withstand the weight of an elephant without breaking, and pop right back up to prepare for the next task.


The research was lead by Katia Bertoldi, the John L. Loeb Associate Professor of the Natural Sciences at the John A. Paulson School of Engineering and Applied Sciences (SEAS), James Weaver, Senior Research Scientist at the Wyss Institute for Biologically Inspired Engineering at Harvard University and Chuck Hoberman, of the Graduate School of Design. It is described in Nature Communications.


"We've designed a three-dimensional, thin-walled structure that can be used to make foldable and reprogrammable objects of arbitrary architecture, whose shape, volume and stiffness can be dramatically altered and continuously tuned and controlled," said Johannes T. B. Overvelde, graduate student in Bertoldi's lab and first author of the paper.


The structure is inspired by an origami technique called snapology, and is made from extruded cubes with 24 faces and 36 edges. Like origami, the cube can be folded along its edges to change shape. The team demonstrated, both theoretically and experimentally, that the cube can be deformed into many different shapes by folding certain edges, which act like hinges. The team embedded pneumatic actuators into the structure, which can be programmed to deform specific hinges, changing the cube's shape and size, and removing the need for external input.


The team connected 64 of these individual cells to create a 4x4x4 cube that can grow, and shrink, change its shape globally, change the orientation of its microstructure and fold completely flat. As the structure changes shape, it also changes stiffness -- meaning one could make a material that's very pliable or very stiff using the same design. These actuated changes in material properties adds a fourth dimension to the material.


"We not only understand how the material deforms, but also have an actuation approach that harnesses this understanding," said Bertoldi. "We know exactly what we need to actuate in order to get the shape we want."


The material can be embedded with any kind of actuator, including thermal, dielectric or even water.


"The opportunities to move all of the control systems onboard combined with new actuation systems already being developed for similar origami-like structures really opens up the design space for these easily deployable transformable structures," said Weaver.


"This structural system has fascinating implications for dynamic architecture including portable shelters, adaptive building facades and retractable roofs," said Hoberman. "Whereas current approaches to these applications rely on standard mechanics, this technology offers unique advantages such as how it integrates surface and structure, its inherent simplicity of manufacture, and its ability to fold flat."


"This research demonstrates a new class of foldable materials that is also completely scalable," Overvelde said, " It works from the nanoscale to the meter-scale and could be used to make anything from surgical stents to portable pop-up domes for disaster relief."

The "birth" of neurons has been witnessed in a live brain for the first time.

Neurons provide the crucial mechanism that allows the brain to operate; 'born' in the hippocampus, they are responsible for processing memories and keeping related, but separate, memories distinct from one another.

 What wasn't always clear is how -- or even if -- new neurons can be made in the brain. Though it now seems clear that they are, that process had never been witnessed first hand -- the brain is complex and delicate, and neurons are extremely small and intricate.

To get around those restrictions, a team at Columbia University Medical Center in New York used several techniques to observe the birth of the neurons -- first implanting a miniature microscope into the brains of mice, and then chaning the mice so that their new neurons would glow enough to be picked up by that device. Once prepared, the mice were placed on a treadmill and ran while they experienced slightly different sights and smells, and were given electric shocks to create an association between the stimuli and the unpleasant experience.


When the neurons were then 'turned off', the mice were no longer able to tell between cues that were neutral and cues that were unpleasant. This, the team says, suggests that the new neurons were responsible for telling the difference between similar memories.

This result was replicated when the mice were placed into identical chambers, in which they had received shocks and rewards at different times.

Because the skill responsible for separating memories is reduced in people with anxiety disorders, the team hope that their research will prove useful for further investigations of depression and anxiety. Many antidepressants "stimulate the production of new hippocampus neurons", the team says, so their new discovery may provide new insight into the link between the neurons and mental illness.

The gaming community has always said that playing video games has more positive sides to it than the negativity portrayed by the non-gaming community, it is a debate many psychologists have also taken up. This time around, we have something to support the latter.

A research has been published in the Social Psychiatry and Psychiatric Epidemiology Journal where they have worked on any connection (direct or indirect) between the time spent playing games and the intellectual functioning/ school competency.

A group of researchers from Paris Descartes University and Columbia Mailman School of Public Health formed a team together and completed the study that reveals rather astonishing (for the non-gaming community because well, we have known it for a good long time already) results.

So the answer to their question “is time spent playing video games associated with mental health, cognitive and social skills in young children,” reveals that not only do the two things have a connection, games have a positive impact on a student’s level of intellect and competency.

One of the fellow researchers, Katherine M. Keyes, who is a PhD and an assistant professor of Epidemiology at the Mailman School of Public Health, says:

If we have put a figure on it, the study reveals that those who play video games have 1.75 times better odds at high intellectual functioning and as much as 1.88 times better odds at high school competency.

Based on this study, gaming has the potential of making you almost twice as intellectual and competent in school as you would be without having been a gamer.