Knowledge Update

​London, July 28 (IANS) Storing carbon dioxide (CO2) in reservoirs deep underground may be better for the climate than emitting the gas directly into the atmosphere as researchers have found that this process is much safer over long periods of time than previously thought.

The researchers found that natural accumulations of CO2 that have been trapped underground for around 100,000 years have not significantly corroded the rocks above.

These findings, published in the journal Nature Communications, demonstrate the viability of a process called carbon capture and storage (CCS) as a solution to reducing carbon emissions from coal and gas-fired power stations, the researchers said.

"With careful evaluation, burying carbon dioxide underground will prove very much safer than emitting CO2 directly to the atmosphere," said lead author Mike Bickle, Professor at University of Cambridge.

Carbon capture and storage involves capturing the carbon dioxide produced at power stations, compressing it, and pumping it into reservoirs in the rock more than a kilometre underground.

The CO2 must remain buried for at least 10,000 years to avoid the impacts on climate.

One concern in this process is that the dilute acid, formed when the stored CO2 dissolves in water present in the reservoir rocks, might corrode the rocks above and let the CO2 escape upwards.

The new research found that CO2 can be securely stored underground for far longer than the 10,000 years needed to avoid climatic impacts.

The study showed that the critical component in geological carbon storage, the relatively impermeable layer of "cap rock" that retains the CO2, can resist corrosion from CO2-saturated water for at least 100,000 years.

To understand these effects, this study examined a natural reservoir in the US state of Utah where large natural pockets of CO2 have been trapped in sedimentary rocks for hundreds of thousands of years. 

The team drilled deep down below the surface into one of these natural CO2 reservoirs to recover samples of the rock layers and the fluids confined in the rock pores.

"A major obstacle to the implementation of CCS is the uncertainty over the long-term fate of the CO2 which impacts regulation, insurance, and who assumes the responsibility for maintaining CO2 storage sites. Our study demonstrates that geological carbon storage can be safe and predictable over many hundreds of thousands of years," Bickle said.

Washington, July 28 (IANS) Medications taken by children to treat attention-deficit/hyperactivity disorder (ADHD) offer long-term benefits, revealed a study.

ADHD is a chronic condition characterised by attention difficulty or hyperactivity and impulsiveness where children can do risky activities like dangerous driving, drug use and risky sexual behaviour.

According to the research, the treatment with ADHD medication made children less likely to suffer consequences of risky behaviour such as sexually transmitted diseases or substance abuse during their teen years and injuries.

"ADHD is such a major issue, but no one seemed to be able to give a very definite answer to the long-term effect of the medication. We were able to see everyone who had an ADHD diagnosis and track their health over time to identify any potential benefits of the medication or the lack of thereof," said Anna Chorniy, Researcher at Clemson University, in the study published in the journal Labour Economics.

For the study, the researchers took nearly 1,50,000 children diagnosed with ADHD and compared them with children who did not receive medication.

Those who took medication were (3.6 per cent) less likely to contract a sexually transmitted disease, than those who did not take medication (7.3 per cent).

While previous research has demonstrated the effectiveness of medications in treating the core symptoms of ADHD, little has been known about the effects of treatment on health, behavioural and educational outcomes in the long run. ​

​London, July 28 (IANS) Astronomers have discovered a new type of exotic binary star system, in which a rapidly spinning white dwarf star is lashing the companion red dwarf star with high-energy particles, causing the entire system to pulse dramatically every 1.97 minutes with radiation ranging from the ultraviolet to radio.

The binary system was discovered by a group of amateur astronomers from Germany, Belgium and Britain. Its behaviour was unlike anything they had ever encountered before.

The true nature of this previously misidentified system was then observed by researchers at the University of Warwick using a multitude of telescopes on the ground and in space, including the NASA/ESA Hubble Space Telescope.

The star system AR Scorpii (AR Sco) lies in the constellation of Scorpius, 380 light years from Earth. 

"AR Scorpii was discovered over 40 years ago, but its true nature was not suspected until we started observing it in June 2015. We realised we were seeing something extraordinary the more we progressed with our observations," said lead researcher Tom Marsh from the University of Warwick.

The radiation across a broad range of frequencies is indicative of emission from electrons accelerated in magnetic fields, which can be explained by AR Sco's spinning white dwarf. 

The source of the electrons themselves, however, is a major mystery -- it is not clear whether it is associated with the white dwarf or its cooler companion, said the study published in the journal Nature.

"We've known about pulsing neutron stars for nearly 50 years and some theories predicted white dwarfs could show similar behaviour. It's very exciting that we have discovered such a system, and it has been a fantastic example of amateur astronomers and academics working together," said study co-author Boris Gansicke. 

​Washington, July 29 (IANS) An in-house data analytics tool recently employed at The New York Times office is not only pulling in data from multiple sources and presenting it at one place in a simplified manner, it is also helping editors and reporters develop better story ideas.

Called “Stela” (story and events analytics), the analytics dashboard was introduced to the NYT newsroom in September last year. 

The tool is now expanding to include better video analytics and deliver useful data points to reporters. 

“Think a daily, desk-specific email, reporting analytics information in the body of the email, distributed in the newsroom,” said a report in www.niemanlab.org.

“We were looking for ways to help reporters and editors get feedback on the things they were being asked to do online, such as tweaking headlines, promoting to social,” Steve Mayne, lead Growth Editor at the Times, was quoted as saying. 

Stela has now 1,300 monthly users -- almost the entire Times news operation staff. “We're excited to be hearing that this tool can be used to help develop story ideas,” Mayne added. 

This is how it works.

The tool pulls in data from the Times' desktop and mobile websites as well as all of the Times' mobile apps.

“In addition to elementary metrics like pageviews and referrals, Stela breaks down other data points such as the percentage of readers coming to each story from different countries and how many readers are subscribers, registered users or anonymous traffic,” the report said. 

It also pulls top comments and shows the social posts that are doing best so that editors can see which Facebook or Twitter posts have been shared or retweeted most widely. 

“Social media editors monitor Stela and can reuse language from the posts that have performed best, rather than trying to eyeball various Twitter or Facebook accounts for what appear to be popular posts,” the niemanlab.org report pointed out. 

The Guardian also has an Ophan in-house analytics engine. The Financial Times is reportedly launching a new analytics tool to make metrics more understandable for its newsroom.

The app is also helping make tangible the importance of mobile-friendly writing and design.

“On so many stories, you'll see 60, 70, 80 per cent of readers coming from mobile, particularly for some of the breaking news stuff,” Mayne was quoted as saying.

​New York, July 27 (IANS) An infusion of stem cells harvested from a patient's own skin could help restore proper drainage for fluid-clogged eyes at risk of glaucoma, a study says.

When fluid accumulates in the eye, the increase in pressure could lead to glaucoma. The disease damages the optic nerve and can result in blindness.

The researchers injected stem cells into the eyes of mice with glaucoma. 

The influx of cells regenerated the tiny, delicate patch of tissue known as the trabecular meshwork, which serves as a drain for the eyes to avoid fluid buildup. 

"We believe that replacement of damaged or lost trabecular meshwork cells with healthy cells can lead to functional restoration following transplantation into glaucoma eyes," said lead researcher Markus Kuehn from University of Iowa in the US.

One potential advantage of the approach is that the type of stem cells used - called induced pluripotent stem cells - could be created from cells harvested from a patient's own skin. 

That gets around the ethical quandary of using fetal stem cells, and it also lessens the chance of the patient's body rejecting the transplanted cells.

Kuehn's team was able to get the stem cells to grow into cells like those of the trabecular meshwork by culturing them in a solution that had previously been "conditioned" by actual human trabecular meshwork cells.

The researchers were encouraged to see that the stem cell injection led to a proliferation of new endogenous cells within the trabecular meshwork. 

In other words, it appears the stem cells not only survived on their own, but coaxed the body into making more of its own cells within the eye, thus multiplying the therapeutic effect.

The team measured the effects in the mice nine weeks after the transplant. 

Laboratory mice generally live only two or three years, and nine weeks is roughly equal to about five or six years for humans.

The researchers say they are confident that their findings hold promise for the most common form of glaucoma, known as primary open angle glaucoma. They are not sure yet if their mouse model is as relevant for other forms of the disease.

The findings were published in the journal Proceedings of the National Academy of Sciences.​

​New York, July 26 (IANS) A new technology to coat fabric in self-healing, thin films may one day lead to chemically protective suits that may prevent farmers from exposure to pesticides, soldiers from chemical or biological attacks in the field and factory workers from accidental releases of toxic materials, say researchers.

"Fashion designers use natural fibres made of proteins like wool or silk that are expensive and they are not self-healing," said Melik Demirel, Professor at Pennsylvania State University in the US.

"We were looking for a way to make fabrics self-healing using conventional textiles. So we came up with this coating technology," Demirel said.

The procedure is simple. The material to be coated is dipped in a series of liquids to create layers of material to form a self-healing, polyelectrolyte layer-by-layer coating.

Polyelectrolyte coatings are made up of positively and negatively charged polymers.

This coating is deposited "under ambient conditions in safe solvents, such as water, at low cost using simple equipment amenable to scale-up," the researchers reported online in the journal ACS Applied Materials & Interfaces.

"We currently dip the whole garment to create the advanced material," Demirel said.

"But we could do the threads first, before manufacturing if we wanted to," he noted.

During the layering, enzymes can be incorporated into the coating. The researchers used urease -- the enzyme that breaks urea into ammonia and carbon dioxide -- but in commercial use, the coating would be tailored with enzymes matched to the chemical being targeted.

"If you need to use enzymes for biological or chemical effects, you can have an encapsulated enzyme with self-healing properties degrade the toxin before it reaches the skin," Demirel explained.

"The coatings are thin, less than a micron, so they wouldn't be noticed in everyday wear," Demirel said. 

For manufacturing environments where hazardous chemicals are necessary, clothing coated with the proper enzyme combination could protect against accidental chemical releases. 

The researchers believe that future use of these coatings in medical meshes could also help patients minimise infections for quick recovery.​

​New York, July 24 (IANS) Dietary changes in the US could feed significantly more people from existing agricultural land, suggests a new study that takes into account the per-person land requirements of different diets.

Using 10 different scenarios ranging from the average American diet to a purely vegan one, a team led by scientists from the Tufts University estimated that agricultural land in the contiguous US could have the capacity to feed up to 800 million people -- twice what can be supported based on current average diets.

The new "food-print" model, published recently in the journal Elementa, shows that a vegetarian diet that includes dairy products could feed the most people from the area of land available.

"Our approach challenges the 20th century emphasis on increasing yield and production. Improving crop yields remains vitally important, but it is not the only way to increase the number of people fed per acre. Our aim is to identify potential agricultural-sustainability strategies by addressing both food consumption and production," said lead author Christian Peters.

The researchers found that a lacto-vegetarian diet (a vegetarian diet that includes dairy products) had the highest carrying capacity, meaning that it could feed the most people from the area of land available.

Diets including some meat can feed more people than vegan diets, depending on estimates of how much land is suitable for crop cultivation, while the baseline diet had the lowest carrying capacity and required eight times more land than a vegan diet.

As the amount of meat in the diet was reduced between scenarios, the amount of land necessary for crops to feed livestock was also reduced.

"In our study, the estimates of carrying capacity for each diet are sensitive to assumptions about the area available for cultivated cropping. Furthermore, since most diet scenarios were consistent with the Dietary Guidelines for Americans, differences in carrying capacity should represent the trade-offs for food preferences rather than nutritional quality," Peters said.​

​Beijing, July 26 (IANS) Archaeologists have confirmed traces of ancient humans, dating back to over 10,000 years, at an altitude of 4,000 metres in China's Qinghai-Tibet plateau.

Hou Guangliang of Qinghai Normal University confirmed that the prehistoric ash layer discovered in 2013 is a residue of human activity, Xinhua news agency reported.

Dozens of stone tools were found at the same site, showing signs of civilisation in the plateau, making it the oldest evidence of human activity at over 4,000 metres.

The discovery is of great significance to research on how ancient humans coped in extreme environments, Hou said.

The plateau has an average altitude of 4,000 metres where winter temperatures can drop to -40 degrees Celsius.​

​London, July 28 (IANS) The impact of low physical capacity on risk of death is second only to smoking, a 45 year study in middle-aged men has found.

"The risk associated with low aerobic capacity was evident throughout more than four decades and suggests that being physically active can have a big impact over a lifetime," said lead author Per Ladenvall from Sahlgrenska Academy at the University of Gothenburg, Sweden. 

"The effect of aerobic capacity on risk of death was second only to smoking," Ladenvall noted.

The study included 792 men from a representative sample of 50-year-old men in Gothenburg recruited in 1963. 

In 1967, at 54 years of age, the men did an exercise test. Of those, 656 men also did a maximum exercise test in which they pushed themselves to the limit. 

The remaining men were excluded from the maximum exercise test because they had a health condition that could make it unsafe. 

Maximal oxygen uptake, called VO2 max, was measured in a sub-population of the 656 men using ergospirometry.

After the initial examination in 1967, the men were followed up until 2012, at the age of 100 years. Several physical examinations were performed, about one every 10 years. Data on all-cause death was obtained from the National Cause of Death Registry.

"We found that low aerobic capacity was associated with increased rates of death,” Ladenvall said.

The findings, published in the European Journal of Preventive Cardiology, showed that low physical capacity is a greater risk for death than high blood pressure or high cholesterol.

"We have come a long way in reducing smoking. The next major challenge is to keep us physically active and also to reduce physical inactivity, such as prolonged sitting," Ladenvall noted.​

New York, July 28 (IANS) Scientists have developed a new space boot with built-in sensors and tiny "haptic" motors whose vibrations can help astronauts avoid the risk of tripping over obstacles.

Falls in space can jeopardise astronauts' missions and even their lives. 

If an astronaut trips over moon rocks, getting to his or her feet in a bulky, pressurised spacesuit can consume time and precious oxygen reserves. Falls also increase the risk that the suit will be punctured. 

Since most falls happen because spacesuits limit astronauts' ability to both see and feel the terrain around them, reseachers from the Massachusetts Institute of Technology (MIT) developed the boot with built-in sensors to guide the wearer around or over obstacles.

"A lot of students in my lab are looking at this question of how you map wearable-sensor information to a visual display, or a tactile display, or an auditory display, in a way that can be understood by a nonexpert in sensor technologies," said Leia Stirling from MIT's Institute for Medical Engineering and Science.

"This initial pilot study allowed Alison [Gibson, a graduate student in AeroAstro and first author on the paper] to learn about how she could create a language for that mapping," Stirling added.

The team presented a prototype of the boot recently at the International Conference on Human-Computer Interaction in Toronto, Canada.

The work could also have applications in the design of navigation systems for the visually impaired. The development of such systems has been hampered by a lack of efficient and reliable means of communicating spatial information to users.​