Knowledge Update

​New York, Dec 16 (IANS) A new planetary system has been discovered with a host star similar to the Earth's Sun but its unusual composition indicates that it has 'eaten' some of its planets.

The study that was published in the journal "Astronomy and Astrophysics" suggest that this new discovery can provide clues to researchers about how planetary systems evolve over time.

"It does not mean that the Sun will 'eat' the Earth any time soon," said Jacob Bean, Assistant Professor University of Chicago.

However, "our discovery provides an indication that violent histories may be common for planetary systems, including our own" Bean said.

In 1995, astronomers discovered the first planet orbiting a star other than the sun. 

Two thousand exoplanets were identified since then including some rare planets that orbit a star similar to Earth's Sun.

Researchers at University of Chicago studied star HIP68468, which is 300 light years away, as part of a multi-year project to discover planets that orbit solar twins. 

"It is tricky to draw conclusions from a single system to study more stars like this to see whether this is a common outcome of the planet formation process," cautioned Megan Bedell, co-author of the study.

The researchers said that the study of HIP68468 was a post-mortem of this process happening around another star similar to our sun and that the discovery deepened their understanding of the evolution of planetary systems.

"HIP68468's composition points to a history of ingesting planets. It contains four times more lithium than would be expected for a star that is six billion years old, as well as a surplus of refractory elements -- metals resistant to heat that are abundant in rocky planets," the research found.

Scientists used the 3.6-meter telescope at La Silla Observatory in Chile to discover their first exoplanet in 2015. 

"The more recent discovery needs to be confirmed, but includes two planet candidates -- a super Neptune and a super Earth. Their orbits are surprisingly close to their host star, with one 50 per cent more massive than Neptune and located at a Venus-like distance from its star. 

"The other, the first super Earth around a solar twin, is three times the Earth's mass and so close to its star that its orbit takes just three days," the study noted.

The scientists said that these two planets most likely did not form where they see them today. 

"Instead, they probably migrated inward from the outer parts of the planetary system. Other planets could have been ejected from the system -- or ingested by their host star," the researchers added.

Researchers continue to explore more than 60 solar twins, eyeing for more exoplanets.

​New York, Dec 16 (IANS) Using the internet in classrooms for study purposes, is likely to affect academic performance, even among the most intelligent and motivated of students, researchers warned.

When internet is used in classrooms, students tend to spend most of their time on social media, reading email, shopping for items such as clothes or watching videos, that could lead to poorer scores.

Internet's use was a significant predictor of students' final exam score, even when their intelligence and motivation were taken into account, said lead author Susan Ravizza, Associate Professor Michigan State University in the US. 

"The detrimental relationship associated with non-academic internet use raises questions about the policy of encouraging students to bring their laptops to class when they are unnecessary for class use," Ravizza said.

Previous research has shown that taking notes on a laptop is not as beneficial for learning as writing notes by hand. 

"Once students crack their laptop open, it is probably tempting to do other sorts of internet-based tasks that are not class-relevant," Ravizza added. 

For the study, the team studied internet use on laptop in a one-hour lecture course with 127 students.

The study showed that using the internet for class purposes did not help students' test scores. 

The findings are forthcoming in the journal Psychological Science.

Washington, Dec 15 (IANS) The US Federal Reserve on Wednesday increased its key interest rate by 25 basis points in the first rate hike in 2016 and just the second in a decade.

​London, Dec 15 (IANS) Whim, a mobile app by Finland-based Mobility as Service (MaaS) operator MaaS Global, is set to be launched in the West Midlands metropolitan area in Britain in early 2017 which will become the first region to pilot the service to its residents.

​New York, Dec 15 (IANS) Next time when you send a message intended for your girlfriend mistakenly to someone else on WhatsApp, relax as you may be able to revoke such messages in the near future.

New York, Dec 15 (IANS) Just by observing how users respond to online videos and other social media content, computers may be able to group them into marketing segments in real time, a new research has revealed. "Computers used information from social media accounts to automatically build marketing personae. Marketing research professionals typically create these personae to help editors and marketers better understand the behaviours of specific consumer groups," said James Jansen, Professor at Penn State University. But it is hard to make a decision looking at a bunch of complex numbers that most people do not understand. To understand these complex numbers, researchers took a bunch of market data and condensed it into a fictitious person. From 188,000 subscribers of a news website, the team developed algorithms to analyse data, such as demographic information, topics of interest and customer interactions. The researchers identified unique ways that groups of people were interacting with the information. "News site editors could use this information to better collect and target content to these audiences," said Jansen, adding "Journalists can use that information to reach readers with better titles, content and article framing." The researchers said that the method was transferable to other domains as well and could work at any consumer touch-point. The method is being scaled up to millions of users where researchers could use other types of social media data from sites like Facebook or Twitter. The study was presented at the second international workshop on online social networks technologies held in Agadir, Morocco, recently.

​New York, Dec 15 (IANS) If you are running out of ideas for your New Year's resolution, consider running. Researchers have found that runners show greater functional connectivity in brain regions important for tasks such as planning and decision-making. "These activities (such as running) that people consider repetitive actually involve many complex cognitive functions -- like planning and decision-making -- that may have effects on the brain," said one of the researchers David Raichlen, Associate Professor at University of Arizona, at Tucson in the United States. For the study, the researchers compared brain scans of young adults engaged in cross-country running to young adults who do not engage in regular physical activity. Participants were roughly the same age -- 18 to 25 -- with comparable body mass index and educational levels. The runners, overall, showed greater functional connectivity -- or connections between distinct brain regions -- within several areas of the brain, including the frontal cortex, which is important for cognitive functions such as planning, decision-making and the ability to switch attention between tasks. The findings, published in the journal Frontiers in Human Neuroscience, suggest that running may affect the structure and function of the brain in ways similar to complex tasks like playing a musical instrument. Since functional connectivity often appears to be altered in ageing adults, and particularly in those with Alzheimer's or other neurodegenerative diseases, it is an important measure to consider, Gene Alexander, Professor at University of Arizona, noted.

Mumbai, Dec 15 (IANS) A study by Indian researchers suggests that a population of neutron stars can generate gravitational waves continuously, a finding that could provide an opportunity to study these waves almost permanently.

The study by Professor Sudip Bhattacharyya of the Tata Institute of Fundamental Research (TIFR), Mumbai, and Professor Deepto Chakrabarty of the Massachusetts Institute of Technology (MIT) in the US found that a population of neutron stars should spin around their axes much faster than the highest observed spin rate of any neutron star. 

The observed lower spin rates are possible if these neutron stars emit gravitational waves continuously, and hence spin down, the researchers said.

Gravitational waves emitted by massive objects is a prediction of Albert Einstein's general theory of relativity, which has recently been discovered during transient phenomena of black hole mergers. 

But the detection of continuous gravitational waves, which could provide an opportunity to study these waves almost permanently, is still elusive. 

Neutron stars are the densest observable objects in the universe, with a fistful of stellar material outweighing a mountain on Earth. 

While such stars are not bigger than a city, in size, they have more material than in the Sun crammed inside them. 

A population of these stars can increase their spin rate by the transfer of matter from a normal companion star. 

In fact, some of them have been observed to spin several hundred times in a second around their own axes.

In the 1970s, it was theoretically worked out how fast these neutron stars could spin, and since then this has formed the basis of studies of these stars. 

But the new study -- published in the The Astrophysical Journal -- showed that for episodic mass transfer, which happens for many neutron stars, the stellar spin rate should be much higher, and the star could easily attain a spin rate more than a thousand times per second. 

Since no neutron star has been observed with such a high spin rate, the team pointed out that many of these stars are likely to be slowed down by continuously emitting gravitational waves.

The new study provides a strong indication that many fast spinning neutron stars generate gravitational waves continuously, and careful observations should be made to detect such waves.

​Washington, Dec 15 (IANS) US space agency NASA launched a constellation of eight small satellites on Thursday designed to aid weather forecasters in understanding and predicting hurricane intensity.

The eight observatories comprising the Cyclone Global Navigation Satellite System (CYGNSS) were delivered to a low-Earth orbit by the US aerospace firm Orbital ATK's Pegasus XL rocket at 8.37 a.m. (local time), Xinhua news agency reported.

The rocket and its micro-satellite payload were air-launched from Orbital ATK's modified L-1011 aircraft, nicknamed Stargazer, which first flew to about 39,000 feet over the Atlantic Ocean and then released the rocket.

NASA said the $157 million CYGNSS mission will team up with the Global Positioning System (GPS) constellation to measure ocean surface winds in and near the eye of the storm throughout the life cycle of hurricanes.

"This will be the first time that satellites can peer through heavy tropical rainfall into the middle of hurricanes and predict how intense they are before and during landfall," it added.

​London, Dec 15 (IANS) Researchers have in a breakthrough study found that brains of people genetically inclined towards Alzheimer's are likely to show abnormal immune reactions as early as about seven years before the expected onset of dementia.

These immune responses can be detected by means of a protein known as "TREM2" and found in the cerebrospinal fluid, offering physicians the possibility to trace the progression of the disease, the study said. 

Thus, when the researchers measured the levels of TREM2 -- segregated by certain immune cells of the brain called microglia -- they were able to detect an increasing immune activity of the brain. 

"The activity of the microglia is stimulated by the dying brain cells, not by the deposits of amyloid proteins, called plaques, which also occur in Alzheimer's disease," said Christian Haass, Professor at Ludwig Maximilian University (LMU) in Munich, Germany.

The rise of TREM2 levels years before the expected occurrence of dementia symptoms can be monitored and thus the timing for the onset of dementia can be precisely predicted, the researchers noted.

"TREM2 levels could therefore be a biomarker used to track immune activity while Alzheimer's is progressing, irrespective of whether the disease is genetic or not. TREM2 may also serve as a therapeutic marker to monitor drug response," explained Michael Ewers, Professor at Ludwig Maximilian University (LMU). 

For the study, the team included 127 individuals, with an average age of 40 years, who had a genetic predisposition to Alzheimer's. The vast majority showed no symptoms of dementia or had only minor cognitive impairments. 

The study results are published in the journal Science Translational Medicine.