Knowledge Update

Washington, Jan 28 (IANS) NASA scientists in an unprecedented study have found that space travel may alter gene expression.

The study involved astronaut Scott Kelly, who spent a year in space and his identical twin Mark who stayed on Earth. 

From the lengths of the twins' chromosomes to the microbiomes in their guts, "almost everyone is reporting that we see differences", Christopher Mason, a geneticist at Weill Cornell Medical College in New York City, was quoted as saying to scientificamerican.com. 

The changes that are likely attributable to Scott's time in orbit include alterations to gene expression, DNA methylation -- the reversible addition of a chemical marker that can affect gene expression -- and other biological markers. 

DNA methylation decreased in Scott during flight and increased in Mark over the same period. 

Levels for both men returned close to pre-flight levels after Scott came back to Earth, according to the preliminary results published in the journal Nature. 

"What this means isn't yet clear," said Andrew Feinberg, a geneticist at Johns Hopkins University in Maryland, US.

The researchers also reported changes in gene-expression signatures between the twins. Such changes happen in earthbound people all the time, associated with environmental shifts such as changes in diet and sleep habits. 

However, the changes in Scott seemed to be larger than normal - perhaps due to the stress of eating frozen food and trying to sleep while floating in space, Mason said.

But, because the Kelly twins are just two people, the results may not be generalised, the study said.

Scott spent 340 days in space during 2015-2016, giving him a lifetime total of 520 days, while Mark, also an astronaut, had previously flown in space for a total of 54 days over four space-shuttle missions between 2001 and 2011.

New York, Jan 28 (IANS) If you are a creative person, chances are you may face more trouble in getting good quality sleep although you may sleep more often, researchers say.

In the study, the researchers sought to understand how two types of creativity -- visual and verbal -- influence objective aspects of sleep such as duration and timing and subjective aspects -- sleep quality.

The findings showed that both have different sleep patterns. Visual creativity is activated by different cerebral mechanisms than verbal creativity.

"Visually creative people reported disturbed sleep leading to difficulties in daytime functioning," whereas, "in the case of verbally creative people, the study found that they sleep more hours, go to sleep late and get up later," Neta Ram-Vlasov, doctoral student at University of Haifa in Israel, said in a statement.

"This strengthens the hypothesis that the processing and expression of visual creativity involves different psychobiological mechanisms to those found in verbal creativity," Ram-Vlasov added.

One possible explanations for the differences can be the that a 'surplus' of visual creativity makes the individual more alert which could lead to sleep disturbances.

"On the other hand, it is possible that it is protracted sleep among verbally creativity individuals facilitating processes that support the creative process while they are awake," Ram-Vlasov said.

​New York, Jan 27 (IANS) Questioning the decision-making ability of driverless cars, experts have suggested model driverless car regulations to ensure safety of the passengers.

Artificial intelligence (AI) experts David Danks and Alex John London from Carnegie Mellon University in the US argued that current safety regulations do not plan for autonomous systems and are ill-equipped to ensure that these systems would perform safely and reliably.

"Currently, we ensure safety on the roads by regulating the performance of the various mechanical systems of vehicles and by licensing drivers. When cars drive themselves we have no comparable system for evaluating the safety and reliability of their autonomous driving systems," said London.

In an opinion piece that appeared in the Institute of Electrical and Electronics Engineers' (IEEE) Intelligent Systems, Danks and London suggested creating a dynamic system that resembles the regulatory and approval process for drugs and medical devices, including a robust system for post-approval monitoring.

"Self-driving cars and autonomous systems are rapidly spreading so we, as a society, need to find new ways to monitor and guide the development and implementation of these autonomous systems," added Danks.

The proposed phased process would begin with "pre-clinical trials," or testing in simulated environments, such as self-driving cars navigating varied landscapes and climates. 

This would provide information about how the autonomous system makes decisions in a wide range of contexts, so that we can understand how they might act in future in new situations, the duo said.

When a vehicle passes this test, the system would move on to "in-human" studies through a limited introduction into real world environments with trained human "co-pilots." 

Successful trials in these targeted environments would then lead to monitored, permit-based testing and further easing of restrictions as performance goals were met, the researchers noted.

New York, Jan 25 (IANS) If you are impulsive in making decisions, chances are that you may become obese, say researchers who found a link between having an impulsive personality and a high body mass index (BMI).

The findings demonstrate that having an impulsive personality -- the tendency to consistently react with little forethought -- is the key factor that links brain patterns of impulsivity and a high BMI.

"Our research points to impulsive personality as a risk factor for weight gain," said lead researcher Francesca Filbey, Associate Professor at The University of Texas at Dallas.

Overweight and obesity are known to increase blood pressure -- the leading cause of strokes.

Excess weight also increases your chances of developing other problems linked to strokes, including high cholesterol, high blood sugar and heart disease.

Thus, "treatments that provide coping skills or cognitive strategies for individuals to overcome impulsive behaviours associated with having an impulsive personality could be an essential component for effective weight-loss programmes", Filbey said.

For the self-report, researchers used an impulsive sensation-seeking scale to gauge innate personality characteristics.

The neuro-psychological measure sought to assess whether an individual's decision-making style was more impulsive or cautious.

An fMRI was used to examine brain activation and connectivity during an impulse control task.

The results showed that "individuals with a high BMI exhibited altered neural function compared to normal weight individuals", Filbey noted.

​New York, Jan 25 (IANS) Early Mars was warmed intermittently by a powerful greenhouse effect caused by methane gas, researchers have revealed.

The team from Harvard University's John A. Paulson School of Engineering and Applied Science (SEAS) found that interactions between methane, carbon dioxide and hydrogen in the early Martian atmosphere may have created warm periods when the planet could support liquid water on the surface.

In a paper published in Geophysical Research Letters, first author Robin Wordsworth wrote that if humans understand how early Mars operated, it could tell something about the potential for finding life on other planets outside the solar system.

Four billion years ago, the Sun was about 30 per cent fainter than today and significantly less solar radiation reached the Martian surface, the paper said, adding that the scant radiation that did reach the planet was trapped by the atmosphere, resulting in warm, wet periods.

As carbon dioxide makes up 95 per cent of today's Martian atmosphere, it alone does not account for Mars' early temperatures.

"You can do climate calculations where you add carbon dioxide and build up to hundreds of times the present day atmospheric pressure on Mars and you still never get to temperatures that are even close to the melting point," said Wordsworth.

Wordsworth and his collaborators looked to these long-lost gases -- known as reducing gases -- and found that billions of years ago geological processes could have released significantly more methane into the atmosphere. 

This methane would have been slowly converted to hydrogen and other gases, in a process similar to that occurring today on Saturn's moon, Titan, the research found.

Wordsworth and his team experimented to see what happens when methane, hydrogen and carbon dioxide collide and how they interact with photons. The team found that this combination resulted in very strong absorption of radiation.

"We discovered that methane and hydrogen and their interaction with carbon dioxide, were much better at warming early Mars than had previously been believed," Wordsworth said.

​London, Jan 25 (IANS) People are more likely to get affected by superbugs due to over use of antibiotics rather than dirty hospitals, a study has found.

The study, led by researchers at the University of Oxford, showed that the widespread prescription of fluoroquinolone antibiotics such as ciprofloxacin was the reason behind a serious stomach bug Clostridium difficile (C. diff), that caused a diarrhoea outbreak in Britain in 2006.

In 2007, a programme of deep cleaning aimed at combating lack of hygiene in hospitals was announced by the National Health Services.

However, the cases of C. difficile fell only when fluoroquinolone use was restricted and used in a more targeted way as one part of many efforts to control the outbreak, the researchers said.

The restricted use of fluoroquinolones resulted in the disappearance in the vast majority of cases and lead to around an 80 per cent fall in the number of these infections.

"Our study shows that the C. difficile epidemic was an unintended consequence of intensive use of an antibiotic class, fluoroquinolones and control was achieved by specifically reducing use of this antibiotic class, because only the C. difficile bugs that were resistant to fluoroquinolones went away," said Derrick Crook, Professor at University of Oxford.

Meanwhile, the smaller number of cases caused by C. diff bugs not resistant to fluoroquinolone antibiotics remained the same.

Infection prevention and control measures such as better handwashing had no impact on the number of C.diff bugs transmitted between people in hospital, the researchers noted.

Ensuring antibiotics are used appropriately is the most important way to control the C. difficile superbug. 

For the study, published in The Lancet Infectious Diseases, the team analysed data on the numbers of C. diff infections and amounts of antibiotics used in hospitals and by doctors in Britain.

London, Jan 24 (IANS) Are you anxious that your kid is hooked to social networking sites or busy playing video games throughout the night? You now have another reason to blame for the growing addiction: Genes.

According to researchers from King's College London, online media use such as social networking, instant messaging and playing games for entertainment and education could be strongly influenced by our genes.

Genetic factors was found to influence time spent on all types of media including entertainment (37 per cent) and educational (34 per cent) media, online gaming (39 per cent) and social networking (24 per cent). 

The study found that people are not passively exposed to media; instead they tailor their online media use based on their own unique genetic predispositions -- a concept known as gene-environment correlation.

"The DNA differences substantially influence how individuals interact with the media and puts the consumer in the driver's seat for selecting and modifying their media exposure according to their needs," said lead author Ziada Ayorech from King's College London. 

"Our findings contradict popular media effects theories, which typically view the media as an external entity that has some effect -- either good or bad -- on 'helpless' consumers," Ayorech added.

In addition, unique environmental factors such as one sibling having a personal mobile phone and the other not, or parents monitoring use of social networks more heavily for one sibling compared to the other, accounted for nearly two-thirds of the differences between people in online media use. 

For the study published in the journal PLOS ONE, the team analysed online media use in more than 8,500 16-year-old twins. 

The researchers compared identical twins -- who share 100 per cent of their genes -- and non-identical twins -- who share 50 per cent of their genes.

London, Jan 24 (IANS) After analysing minerals from 43 rare meteorites that landed on Earth 470 million years ago, a team of scientists proposes to revise the current understanding of the history and development of the solar system.

There was a giant collision in outer space 460 million years ago. Something hit an asteroid and broke it apart, sending chunks of rock falling to Earth as meteorites since before the time of the dinosaurs. 

The discovery confirms the hypothesis presented by geology professor Birger Schmitz at Lund University in Sweden. He found what he referred to as an "extinct meteorite" - a meteorite dinosaur - which was named "Osterplana 065".

The term 'extinct' was used because of its unusual composition, different from all known groups of meteorites, and because it originated from a celestial body that was destroyed in ancient times.

The discovery led to the hypothesis that the flow of meteorites may have been completely different 470 million years ago compared to today, as meteorites with such a composition no longer fall on Earth.

"The new results confirm the hypothesis. Based on 43 micrometeorites, which are as old as Österplana 065, the new study shows that back then, the flow was actually dramatically different," said Schmitz. 

Schmitz conducted the study with colleagues at Lund University, the University of Chicago, and the University of Wisconsin-Madison. 

"We can now recreate late history of not only the Earth but of the entire solar system. The scientific value of this new report is greater than the one last summer", Schmitz added in a paper published in the journal Nature Astronomy.

"We found that the meteorite flux, the variety of meteorites falling to Earth, was very, very different from what we see today," added the paper's lead author Philipp Heck of The Field Museum in Chicago.

Beijing, Jan 24 (IANS) China plans to build a next-generation synchrotron radiation facility in Beijing, according to a researcher from Chinese Academy of Sciences.

Dong Yuhui said on Monday that the project is expected to start in November 2018 and will be completed in six years. The total investment will reach 4.8 billion yuan ($698 million), the China Daily reported.

The facility, dubbed Beijing Light Source, will meet the national security demands and create aerospace materials among other products. It will provide high-resolution method to know substantial structures better.

Beijing Light Source will be the so-called fourth generation light source and its key performance indicators would be higher than the third-generation ones.

It will create the brightest X-rays worldwide, 70 times brighter than the US National Synchrotron Light Source II (NSLS-II) and 10 times brighter than Sweden's MAX IV, the strongest of its kind in the world.

Bright X-rays could help measure the atomic structure of various substances and the higher brightness will help people to see more details of substances, something akin to using flashlight to see things, Dong said.

Around the world, there are more than 50 such facilities providing support in many research fields. 

The light source plays an important role in the medical field, helping researchers know mechanisms of tumours and cerebrovascular diseases.