Knowledge Update

Washington, Feb 22 (IANS) NASA's Fermi gamma-ray space telescope has found a signal at the centre of the neighbouring Andromeda galaxy that could be coming from dark matter, an unknown substance that makes up most of the universe, according to a study.

The gamma-ray signal is similar to one seen by Fermi at the centre of our own Milky Way galaxy.

"Our galaxy is so similar to Andromeda, it really helps us to be able to study it, because we can learn more about our galaxy and its formation," said study co-author Regina Caputo, a research scientist at NASA's Goddard Space Flight Centre in Greenbelt, Maryland. 

Gamma rays are the highest-energy form of light, produced by the universe's most energetic phenomena.

They are common in galaxies like the Milky Way because cosmic rays, particles moving near the speed of light, produce gamma rays when they interact with interstellar gas clouds and starlight.

Surprisingly, the latest Fermi data shows the gamma rays in Andromeda -- also known as M31 -- are confined to the galaxy's centre instead of spread throughout, said the study to be published in an upcoming issue of The Astrophysical Journal.

To explain this unusual distribution, scientists are proposing the emission may come from several undetermined sources. One of them could be dark matter.

"We expect dark matter to accumulate in the innermost regions of the Milky Way and other galaxies, which is why finding such a compact signal is very exciting," said led scientist Pierrick Martin, an astrophysicist at the National Center for Scientific Research and the Research Institute in Astrophysics and Planetology in Toulouse, France. 

"M31 will be a key to understanding what this means for both Andromeda and the Milky Way," Martin said.

Another possible source for this emission, according to the scientists, could be a rich concentration of pulsars in M31's centre.

Sydney, Feb 21 (IANS) Australia's New South Wales state will focus on better preparing students for university and employment in a major overhaul of its school curriculum.

New South Wales on Tuesday unveiled changes to its high school syllabus for the first time in 18 years, the BBC reported.

The new focus eschews "social context" teaching -- which had drawn criticism -- for more in-depth, critical thinking.

It comes after an international study in December showed Australia's maths and science ranking had tumbled.

The changes address recent criticism over a lack of rigour, said Tom Alegounarias, the head of the state's Education Standards Authority.

"We reviewed the whole (syllabus), we looked at what the community is demanding for now and in the future," Alegounarias told the Australian Broadcasting Corporation.

"The major shift is towards greater depth, rigour, and mastery of content learning."

However, education officials said the concerns were addressed.

Maths will now include more statistics and algorithms, such as those used by internet search engines.

In English, texts will no longer be studied through themes like "journey" or "discovery" but examined for their individual merit.

In history, subjects such as the Enlightenment and the Industrial Revolution will be explored in depth, rather than focusing on a breadth of topics.

The new curriculum will be introduced from next year, the BBC added.

New York, Feb 21 (IANS) Adolescents suffering from trauma and stress are likely to have impairment in the ability to recognise facial expressions that is critical for social functioning and communicating emotions, researchers say.

The findings showed that adolescents with post-traumatic stress disorder (PTSD) symptoms are more likely to misidentify sad and angry faces as fearful.

"Our findings suggest that exposure to stress and trauma can have acute emotional impacts that simply translate to misidentification of important affective cues," said lead author Shabnam Javdani, Assistant Professor at New York University - Steinhardt in the US.

"Fear is particularly relevant for understanding PTSD, as the disorder has been associated with a 'survival mode' of functioning characterised by an overactive fight-or-flight response and increased threat perception," Javdani added.

In contrast, teens with conduct disorder -- a group of behavioural and emotional problems characterised by callousness or aggression towards others -- were more likely to misidentify sad faces, but did not have trouble recognising angry or fearful faces. 

Conduct disorder symptoms were associated with mistaking sadness for anger, suggesting that youth with higher levels of conduct disorder interpret sad faces as angry and may be less effective at recognising others' sadness, pain and suffering.

"Difficulty interpreting displays of sadness and misidentifying sadness as anger may contribute to the impaired affective bonding, low empathy, and callous behaviour observed in teens with conduct disorder," Javdani said.

For the study, published in the journal Child and Adolescent Mental Health, the team examined 371 teens, ages 13-19, to understand the effects of PTSD and conduct disorder symptoms on how youth with emotional and behaviour problems process facial expressions. 

Enhancing the accuracy of recognising facial expressions may be an important treatment goal for youth with symptoms of PTSD and conduct disorder, the researchers said.

​London, Feb 21 (IANS) Offering a glimmer of hope for people suffering from chronic nerve pains, researchers have found that a novel substance inhibits the pain effectively and is well tolerated.

The standard treatment for this chronic nerve pain, known as trigeminal neuralgia, a condition that can lead to acute pain in the teeth or facial area, is associated with burdening side effects. 

In this study, published in the journal Lancet Neurology, the substance, BIIB074, was found to reduce the pain to a tolerable level.

"Unlike conventional drugs, which often cause tiredness and concentration problems, BIIB074 was not only effective, but also very well tolerated," said one of the researchers, Dominik Ettlin, a dental specialist at University of Zurich in Switzerland. 

"We will now test the new substance in a lot more subjects during the next study phase, which will reveal whether the new hope for more effective pain relief is justified," he added.

Bouts of pain in people with trigeminal neuralgia can be triggered by touch, such as shaving, putting on make-up, showering, talking and tooth brushing, or even a gust of wind. 

The cause is usually an irritation of the trigeminal nerve, the cranial nerve responsible for the sensory innervation of the facial area, parts of the scalp, and the oral cavity.

Pain signals reach the brain via the activation of sodium channels located in the membranes of nerve cells. 

The sodium channel "1.7" is frequently expressed on pain-conducting nerves and higher pain intensity is linked to higher channel activity. 

Blocking this sodium channel inhibits the pain. 

In trigeminal neuralgia, the nerve damage is presumed to be at the base of the skull. However, this region is hard to reach by local injections and therefore requires drug treatment.

In this study, the researchers found that the more active this sodium channel gets, the stronger it is blocked by the novel substance BIIB074. 

By contrast, currently available medications block the sodium channel irrespective of the nerve activity, which commonly results in burdening side effects, the study said.

​New York, Feb 21 (IANS) Love to eat fish and other seafood? Be careful, as eating mercury-rich fish such as shark and swordfish may increase the risk of developing amyotrophic lateral sclerosis (ALS) -- that takes away the ability of nerve cells to interact with the body's muscles -- a study has warned.

Mercury -- a heavy metal known to be toxic at high levels, causing brain, heart, kidney, lung and immune system damage -- is found high in swordfish and shark, while salmon and sardines typically have lower levels. 

However, the study does not suggest a higher risk of ALS -- also referred to as Lou Gehrig's disease -- from general consumption of seafood.

"For most people, eating fish is part of a healthy diet. But questions remain about the possible impact of mercury in fish," said Elijah Stommel from Dartmouth College in New Hampshire, US.

For the study, the team surveyed 518 people, 294 of whom had ALS and 224 of whom did not and the frequency that the participants reported eating fish with high mercury levels. 

Researchers also measured the levels of mercury found in toenail samples of participants with ALS.

The results, presented at the American Academy of Neurology's 69th Annual Meeting in Boston, revealed that 61 per cent people had a 25 per cent estimated annual mercury intake. These were at double the risk for ALS compared to those with lower levels.

The findings does not negate the fact that eating fish provides many health benefits.

But, people should choose species that are known to have a lower mercury content and avoid consuming fish caught in waters where there is mercury contamination, the researchers suggested.

New York, Feb 20 (IANS) People living in big cities with a large density of population are more likely to prefer long-term romantic relationships, have fewer children and invest more in education, suggesting that they value quality over quantity, researchers say.

The findings showed that urban citizens are more likely to adopt a 'slow life strategy', contrary to the popular notion that crowded places are chaotic and socially problematic.

"People who live in dense places seem to plan for the future more, prefer long-term romantic relationships, get married later in life, have fewer children and invest a lot in each child. They generally adopt an approach to life that values quality over quantity," said lead author Oliver Sng, a postdoctoral fellow at the University of Michigan. 

In environments where population density is low and there is thus relatively little competition for available resources, there are few costs but lots of advantages to adopting a 'fast' strategy.

On the other hand, when the environment gets crowded, individuals have to compete vigorously with others for the available resources and territory, the researchers said.

"So a slow strategy -- in which one focuses more on the future and invests in quality over quantity -- tends to enhance the reproductive success of individuals in high density environments," added Steven Neuberg Professor at Arizona State University. 

For the study, published in the Journal of Personality and Social Psychology, the team used data from nations around the world and the 50 US states. 

In a series of experiments -- for example, in which people read about increasing crowdedness or heard sounds of a crowded environment -- they found that perceptions of crowdedness cause people to delay gratification and prefer slower, more long-term, mating and parenting behaviours.

​New York, Feb 20 (IANS) Unlike other forms of caregiving, mothers singing to their babies is a universal behaviour, and new research shows that the act could be mutually beneficial for both the mother and the child.

While the songs provide the babies much-needed sensory stimulation that can focus their attention, the act of singing can help mothers bond with their babies and also fight postpartum depression, the study said.

Mothers experience a much-needed distraction from the negative emotions and thoughts associated with depression, while also feeling empowered as a parent.

The study, published in the Journal of Music Therapy, also explored the acoustic parameters in the singing voices of mothers with post-partum depression.

"The extraction and analysis of vocal data revealed that mothers with post-partum depression may lack sensitivity and emotional expression in their singing," said study author Shannon de l'Etoile, Professor of Music Therapy at University of Miami Frost School of Music in the US.

"Although the infants were still engaged during the interaction, the tempo did not change and was somewhat robotic," de l'Etoile said.

But the the lack of sensitivity and emotional expression seemed to matter less to the infants as long as they were listening to their mothers.

"Mothers around the world sing to their infants in remarkably similar ways, and infants prefer these specialized songs," de l'Etoile said. 

"The tempo and key certainly don't need to be perfect or professional for mothers and infants to interact through song. In fact, infants may be drawn to the personalised tempo and pitch of their mother, which encourage them to direct their gaze toward and ultimately communicate through this gaze," she added.

New York, Feb 20 (IANS) Sensational content have more staying power than substantive posts on the microblogging platform Twitter, says a study.

In other words, posts about provocative topics are retweeted more by users, thereby making Twitter appear more like a tabloid than a substantive discussion forum for a casual user, the study suggests.

The findings are based on analysis of tweets sent before, during and after the Republican primary debates leading up to the 2016 US presidential election.

"Whereas during the debate tweets focused on a mix of substantive topics, the tweets that had the longest staying power after the debates were those that focused on the more sensationalist news events, often through pictures and videos," said the study by researchers from University of Pennsylvania and Columbia University in the US.

"As such, a user coming to Twitter after the debate was over would have encountered a different topical and emotional landscape than one who had been following the site in real-time, one more closely resembling a tabloid than a substantive discussion forum," the study said.

The study found that entertaining or sensational posts wash out more substantive tweets overtime, The Daily Pennsylvanian reported on Monday. 

Twitter has a greater impact on political discourse than other social media platforms because Twitter users often see content from people they do not know, one of the study authors Ron Berman from The Wharton School, University of Pennsylvania, was quoted as saying.

Twitter users can search using a hashtag or trending topic to see public tweets from a diverse population of users.

​Beijing, Feb 20 (IANS) Majority of Chinese families that have a second child are happier, according to a survey.

The survey, jointly conducted by Radio Guangdong News Channel and a number of fertility websites, interviewed nearly 10,000 two-child families, with 63 per cent reporting feeling happier after the birth of the second child, Xinhua news agency reported on Monday.

The major reason for the rise in happiness was seeing two children grow up together.

After decades of the one-child policy, many parents are believed to be concerned as to whether their first child could accept a younger sibling.

However, the survey found that 44 per cent of children were fine with a younger sibling, and only 1.5 per cent could not accept a sibling at all.

"Though having a second child is often described as tiring, it is not a burden but a happiness to see two children beginning to get along well and keeping each other company," said Zhu Yuzi, who worked for the survey team and is a mother of two.

Starting in the late 1970s, China's one-child policy ended on January 1, 2016, when the government allowed all married couples to have two children.

In 2016, there were 18.67 million newborns in China, 11 per cent more than in 2015, and about 45 per cent of them were not the first child, according to the National Health and Family Planning Commission.

According to the survey, though 47 per cent of parents have husbands that help more with the child-raising after a second child, 57 per cent of wives said they had to quit their jobs to take care of the children.

New York, Feb 19 (IANS) Researchers have developed an electrode that is more durable and could allow for improved restoration of mobility after spinal cord accidents, as well as improved powered prosthetic limbs.

This "glassy carbon" electrode that is patterned inside chips lasts longer in the body and transmits clearer and more robust signals than available electrodes.

When people suffer spinal cord injuries and lose mobility in their limbs, it is a neural signal processing problem. The brain can still send clear electrical impulses and the limbs can still receive them but the signal gets lost in the damaged spinal cord.

According to the study, published in the journal Nature Scientific Reports, this new chip can record neural electrical signals and transmit them to receivers in the limb, bypassing the damage and restoring movement.

"Glassy carbon is much more promising for reading signals directly from neurotransmitters. You get about twice as much signal-to-noise. It's a much clearer signal and easier to interpret," said Sam Kassegne, one of the study's lead investigators. 

The current material for electrodes in these devices is thin-film platinum which can fracture and fall apart over time.

Researchers in Kassegne's lab are using these new and improved brain-computer interfaces to record neural signals both along the brain's cortical surface and from inside the brain at the same time.