Knowledge Update

​Singapore, Dec 13 (IANS) Rating agency Moodys Investors Services said on Tuesday that its outlook for banks in the Asia-Pacific region remains negative for 2017 based on the assumption of a difficult operating environment impacting banks' asset quality and profitability.

​New York, Dec 13 (IANS) An intense flare detected last year in a distant galaxy about four billion light years from Earth, considered to be the brightest supernova ever observed, is actually a tidal disruption event (TDE) -- the destruction of a star by a rapidly spinning supermassive black hole, suggests new research.

The findings are based on new astronomical observation data from the Las Cumbres Observatory (LCO), a global robotic telescope network, and the Hubble Space Telescope.

"We observed the source for 10 months following the event and have concluded that the explanation is unlikely to lie with an extraordinarily bright supernova," said lead researcher Giorgos Leloudas from Weizmann Institute of Science in Israel.

"Our results indicate that the event was probably caused by a rapidly spinning supermassive black hole as it destroyed a low-mass star," Leloudas explained.

Using images from the Hubble Space Telescope that were not available when the event, called ASASSN-15lh, was observed, the scientists found that the event occurred at the centre of the galaxy where the supermassive black hole resides. 

The black hole inferred to lie in this galaxy is more than 100 million times the mass of the sun.

For a star to be tidally disrupted by such a massive black hole -- rather than swallowed whole -- the black hole must be spinning very rapidly, said the study published in the journal Nature Astronomy.

This discovery marks the first time that a TDE has been used to probe the spin of a black hole, a property that is very difficult to measure and is used to infer the existence of so-called Kerr black holes.

ASASSN-15lh occurred when the star strayed too close to the supermassive black hole and was torn apart by the tides generated by the extreme gravity. 

The stellar material orbited around the black hole, collided with itself at high velocity and started falling into the black hole. 

This released copious amounts of energy and generated the bright flare astronomers observed as ASASSN-15lh.

"Years ago we just wouldn't have been able to follow an event like this," study co-author Andy Howell, University of California, Santa Barbara, US, noted.

"This study shows that large area surveys, a global robotic telescope network and a NASA satellite can come together to reveal dramatic new discoveries that wouldn't be possible without each piece of that puzzle," Howell said.

​New York, Dec 13 (IANS) Researchers have identified that bone marrow-derived cells are the source of suPAR -- a protein recently identified as both a reliable marker for chronic kidney disease and a pathogen of the often deadly condition.

The place of origin of suPAR in the human body had been a mystery until now. 

"SuPAR is not just a biomarker; it may also be a cause of the disease," said Jochen Reiser, Professor at Rush University in Illinois, US.

Thus the new discovery may aid search for kidney disease treatment and prevent recurrence after transplant, the researchers said. 

The research showed a type of immature myeloid cell, located in the bone marrow, as the source of abnormal levels of suPAR.

"These immature myeloid cells appear as a main source of circulating suPAR," Reiser added.

Myeloid cells are one of three main types of blood cells. It appears that "these cells are producing high amounts of suPAR, which becomes the mediator that communicates between the immune system and the kidney. At high levels, suPAR travels to the kidneys, causes a reaction, and takes the kidney down," Reiser explained.

The researchers identified bone marrow GR-1lo, Sca1+ immature myeloid cells as the specific type of cells giving rise to suPAR.

"The benefit of knowing what we know about suPAR is that it will allow for much better risk stratification," Reiser said. 

While smoking cessation and losing weight can help bring suPAR levels down. SuPAR levels will likely require pharmacological intervention because "suPAR still won't go down to completely normal levels just because of a better lifestyle," Reiser says.

As for treatments, "stem cell transplantation may prove to be a viable approach to treat diseases such as suPAR-associated kidney disease," the study, published in the journal Nature Medicine, stated.

​London, Dec 13 (IANS) Music may influence a man's ability to focus. While classical music can boost the concentration, rock music can distract, a new research has found.

Interestingly, women's ability to focus is not much affected by the background music -- be it Mozart or AC/DC, the study showed.

"One of our areas of research is how we can boost performance in many different settings -- from rowing in the Olympics, to a musical performance or delivering an important speech," said lead author Daisy Fancourt from the Centre for Performance Science, a collaboration between Imperial College London and the Royal College of Music in Britain.

"This study suggests that for men who are operating or playing a board game, rock music may be a bad idea," Fancourt noted.

In the study, the research team asked 352 participants to play the game Operation.

This game involves removing various body parts from a pretend patient -- Cavity Sam -- whose nose flashes and buzzes if your tweezers touch the metal sides of the body.

Researchers gave the volunteers headphones that played one of three tracks -- Andante from Sonata for Two Pianos by Mozart, Thunderstruck by AC/DC, or the sound of an operating theatre.

The team then timed them how long it took the participants to remove three body parts, as well as tracking their mistakes.

The results revealed that men who listened to AC/DC were slower and made more mistakes, compared to men who listened to Mozart or the sound of an operating theatre.

Thunderstruck triggered around 36 mistakes on average, while the Sonata and operating theatre noises caused 28.

It took volunteers around one minute to complete the task.

Women, however, did not seem to be distracted by the rock music, and none of the three tracks made any difference to performance or speed, showed the findings published in the Medical Journal of Australia.

Generally, women took longer to remove the body parts, but made fewer mistakes.

The researchers are unsure why rock music affected men more than women. 

One explanation, they said, could be that rock music causes more auditory stress -- a state triggered by loud or discordant music -- in men.

The scientists also asked people about their musical tastes, and found that Mozart only reduced the number of mistakes people made if they reported high levels of appreciation for the Sonata they listened to.

New York, Dec 13 (IANS) Researchers have found that intermittent fasting inhibits the development and progression of the most common type of childhood leukemia.

This strategy was not effective, however, in another type of blood cancer that commonly strikes adults.

"This study using mouse models indicates that the effects of fasting on blood cancers are type-dependent and provides a platform for identifying new targets for leukemia treatments," said senior author of the study Chengcheng (Alec) Zhang, Associate Professor at University of Texas Southwestern Medical Center in the US.

"We also identified a mechanism responsible for the differing response to the fasting treatment," he added.

Acute lymphoblastic leukemia, the most common type of leukemia found in children, can occur at any age. Acute myeloid leukemia (AML) is more common in adults.

The two types of leukemia arise from different bone marrow-derived blood cells, he explained. 

Acute lymphoblastic leukemia affects B cells and T cells, two types of the immune system's disease-fighting white blood cells. 

AML targets other types of white blood cells such as macrophages and granulocytes, among other cells.

In both ALL and AML, the cancerous cells remain immature yet proliferate uncontrollably.

Those cells fail to work well and displace healthy blood cells, leading to anemia and infection. They may also infiltrate into tissues and thus cause problems.

The researchers created several mouse models of acute leukemia and tried various dietary restriction plans. 

They used green or yellow florescent proteins to mark the cancer cells so they could trace them and determine if their levels rose or fell in response to the fasting treatment, Zhang explained.

"Strikingly, we found that in models of ALL, a regimen consisting of six cycles of one day of fasting followed by one day of feeding completely inhibited cancer development," he said. 

At the end of seven weeks, the fasted mice had virtually no detectible cancerous cells compared to an average of nearly 68 per cent of cells found to be cancerous in the test areas of the non-fasted mice, showed the findings published online in the journal Nature Medicine.

"Mice in the ALL model group that ate normally died within 59 days, while 75 percent of the fasted mice survived more than 120 days without signs of leukemia," Zhang said.

Fasting is known to reduce the level of leptin, a cell signalling molecule created by fat tissue. 

"We found that fasting decreased the levels of leptin circulating in the bloodstream as well as decreased the leptin levels in the bone marrow," he added.

Interestingly, acute myeloid leukemia was associated with higher levels of leptin receptors that were unaffected by fasting, which could help explain why the fasting treatment was ineffective against that form of leukemia.

New York, Dec 13 (IANS) Genes that are known to be essential to life -- the ones that human beings need to survive and thrive in the womb -- also play a critical role in the development of autism spectrum disorder (ASD) and lead to the disruption of normal social behaviour, suggests a new study.

ASD is a serious developmental disorder that impairs the ability to communicate and interact.

The findings suggest that ASD stems from an aggregate effect of many damaged essential genes that "work" together during the early stages of development in the womb, as soon as eight weeks after conception. 

ASD is a polygenic disease where many small gene effects contribute to a disorder, the researchers said.

"We know it's not one gene that's causing autism spectrum disorders; it's a background of mutations," said Maja Bucan, professor at the University of Pennsylvania in the US. 

For the study, the researchers analysed almost 4,000 essential genes and 5,000 non-essential genes in 2,013 males with ASD and 317 females with ASD, as well as their siblings who did not have ASD, for known exonic de novo (began in the child) and inherited mutations. 

They found that those with ASD had statistically significant elevated levels of mutations in essential genes compared to their siblings. 

The essential gene mutations were associated with a higher risk of ASD and disruption in normal social behaviour, the researchers noted.

On average, those with ASD had 44 per cent more early-in-childhood mutations and 1.3 per cent more inherited mutations in essential genes than their non-affected siblings.

In addition, the researchers identified a list of 29 "high-priority" essential genes that are co-expressed in the developing human brain with previously identified ASD-associated genes. 

"Focusing in on this group of genes will help shed more light on the complex genetic architecture of this disorder," explained Xiao Ji, a doctoral student at the University of Pennsylvania. 

The study was published online in the journal PNAS.

​New York, Dec 13 (IANS) Astronomers believe they have found compelling evidence for two newborn planets, each about the size of Saturn, orbiting around a young star known as HD 163296.

These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the star's protoplanetary disk, the researchers said.

In studying HD 163296, the research team used Atacama Large Millimeter/submillimeter Array (ALMA) to trace, for the first time, the distribution of both the dust and the carbon monoxide (CO) gas components of the disk at roughly the same level of detail.

"Our new observations provide intriguing evidence that planets are indeed forming around this one young star," said study lead author Andrea Isella, astronomer at Rice University in Houston, Texas, US.

HD 163296 is roughly five million years old and about twice the mass of the Sun. It is located approximately 400 light-years from Earth in the direction of the constellation Sagittarius.

The researchers found three distinct gaps in the star's dust-filled protoplanetary disk. 

Using ALMA's ability to detect the faint millimeter-wavelength "glow" emitted by gas molecules, Isella and his team discovered that there was also an appreciable dip in the amount of carbon monoxide in the outer two dust gaps.

By seeing the same features in both the gas and the dust components of the disk, the astronomers believe they have found compelling evidence that there are two planets coalescing remarkably far from the central star. 

The width and depth of the two carbon monoxide gaps suggest that each potential planet is roughly the same mass as Saturn, the astronomers said in a study published in the journal Physical Review Letters.

In the gap nearest to the star, the team found little to no difference in the concentration of CO gas compared to the surrounding dusty disk. 

This means that the innermost gap could have been produced by something other than an emerging planet, the study said.

New York, Dec 13 (IANS) After allowing drivers to test retaking control of an autonomous car on a track, researchers found the transition could be risky.

Twenty-two participants drove a 15-second course consisting of a straightaway and a lane change, then took their hands off the wheel and the self-drive car took over, bringing them back to the start.

After going through the process four times, they drove the course 10 additional times with steering conditions that were modified to represent changes in speed or steering, Xinhua news agency reported.

It was noticeable under the researchers' watch that the drivers wobble the wheel to account for over- and understeering, according to a study published last week in the first issue of Science Robotics.

These challenges bring up the possibility that, depending on the particulars of the driver, the driving conditions and the autonomous system being used, the transition back to driver-controlled driving could be an especially risky window of time.

"Many people have been doing research on paying attention and situation awareness. That's very important," said Holly Russell, lead author of the research and former graduate student in the Dynamic Design Lab at Stanford University.

"But, in addition, there is this physical change and we need to acknowledge that people's performance might not be at its peak if they haven't actively been participating in the driving."

New York, Dec 13 (IANS) Breeding rice to require less flooding, altering feed for livestock to lessen intestinal processes that create methane, promoting less meat-intensive diets and deploying more farm bio-digesters can be possible solutions for reducing the polluting gas from food production, a study has shown.

In the journals Earth System Science Data and Environmental Research Letters published on Monday, a group of international researchers reported that emissions of methane have jumped dramatically in recent years and are approaching an internationally recognised worst-case scenario for greenhouse gas emissions, thus speeding sea level rise and more extreme weather.

While most climate change mitigation efforts have focused on carbon dioxide, methane's warming potential is about 28 times greater on a 100-year horizon, and its lifespan in the atmosphere is much shorter, Xinhua news agency reported.

"Methane presents the best opportunity to slow climate change quickly," said Rob Jackson, the papers' co-author and chair of Stanford University's Earth System Science Department. "Carbon dioxide has a longer reach, but methane strikes faster".

Unlike carbon dioxide, the bulk of methane emissions are human-driven. Chief among those, according to the analysis, are agricultural sources such as livestock, which emit methane through bodily functions and manure, and rice fields, which emit methane when flooded.

Natural sources of methane, which account for 40 per cent of all methane emissions, are more uncertain than human-driven ones, which are responsible for 60 per cent of all methane emissions globally. Examples include methane leaking out of natural faults and seeping on the ocean floor, and the potential for increased emissions as permafrost warms.

Besides efforts proposed to curb emissions from agriculture, the researchers said opportunities in other areas include venting and flaring of methane in coal mines, detecting and removing natural gas leaks from oil and gas drilling operations and covering landfills to capture methane emissions.

"We still need to cut carbon dioxide emissions," Jackson said, "but cutting methane provides complementary benefits for climate, economies and human health".

​London, Dec 19 (IANS) Skin plays a significant role in harbouring and transmitting trypanosomes -- the parasite that causes the Human African Trypanosomiasis, more commonly known as African sleeping sickness, which is often fatal if left untreated, a new research has found.

The findings could have a major impact on the way the disease is diagnosed, treated and potentially eradicated.

The disease, which kills thousands in Sub-Saharan Africa every year, is primarily transmitted to humans via the bite of an infected tsetse fly as it takes a blood meal, with diagnosis then confirmed through the presence of parasites in the blood.

The current study, published recently in the journal eLife, showed that substantial quantities of trypanosomes that cause the disease can exist within the skin and can be transmitted back to the tsetse fly vector.

"Our results have important implications with regard to the eradication of sleeping sickness. Firstly, our findings indicate that current diagnostic methods, which rely on observing parasites in the blood, should be re-evaluated and should include examining the skin for parasites," said lead researcher Annette MacLeod from University of Glasgow in Britain.

"In terms of treatment, it may also be necessary to develop novel therapeutics capable of targeting sources of infection outside the blood circulation and in the reservoirs underneath the skin," MacLeod noted.

The team of researchers from University of Glasgow's Wellcome Trust Centre for Molecular Parasitology and the Institut Pasteur in Paris were also able to observe the presence of parasites in human skin biopsies from individuals who displayed no symptoms. 

The study's findings suggest skin-dwelling parasites could be sufficiently abundant in the skin to be ingested, transmitted and so able to spread the disease further.