Knowledge Update

Tokyo, March 16 (IANS) To understand the effects of microgravity on crystal growth, a team of Japanese researchers has measured the growth of crystals in a specially-designed chamber on board the International Space Station (ISS).
The researchers monitored the very slow growth and dissolution rate -- approximately one centimetre per second of the crystals by a method called laser interferometry.

This was the first time the technique had been used onboard the orbiting international laboratory to measure the growth rate of the crystals at various temperatures.

“We are interested in the growth mechanisms of a space-grown protein crystal -- a lysozyme crystal -- as a model crystal to understand why space-grown crystals sometimes do show better quality than the Earth-grown crystals," explained Tomoya Yamazaki, PhD student in Katsuo Tsukamoto's lab in Tohoku University's department of earth and planetary science in Sendai, Japan.

To observe this, Yamazaki and his colleagues developed unique growth cells suitable for long-term projects for about six months.

For the researchers studying protein crystal growth, that distance was 250 miles up -- the altitude at which the ISS orbits the Earth.

The experimental process, known as NanoStep, was performed in the Japanese Experimental Module (KIBO) of the ISS.

Tsukamoto and his colleagues had previously measured the growth rates of protein crystals under simulated microgravity by using a Russian recoverable satellite and aircraft in parabolic flights.

The researchers took precise measurements of the growth rate of the lysozyme crystals versus their driving force and supersaturation. This also yielded crucial information about the growth mechanism.

Tsukamoto and his colleagues detailed the growth method in the journal Review of Scientific Instruments.

While the researchers expected growth rates of the crystal solution to be slower because of the suppression of solution convection, the results instead showed an increased growth rate.

Extended projects for the researchers using the same apparatus to test the growth of different crystals, such as glucose isomerase crystals, are currently in preparation.​

​New York, March 17 (IANS) Poor and unhealthy diet coupled with lack of exercise and a sedentary lifestyle may accelerate the ageing process in humans, warn US researchers.​
A type of cells called senescent cells contribute to diseases and conditions associated with age. 

The researchers found that exercise prevents premature senescent cell accumulation and protects against the damaging effects of an unhealthy diet, including deficiencies in physical, heart and metabolic function.

"We think that at both biological and clinical level, poor nutrition choices and inactive lifestyles do accelerate ageing," said senior author Nathan LeBrasseur from Mayo Clinic in the US.

In the study, researchers introduced mice to either a normal, healthy diet or a diet that they termed a "fast food diet" -- one that was high in saturated fat and cholesterol along with a sugar-sweetened beverage. 

Mice on the fast food diet showed harmful changes in health parameters, including body weight and composition, increasing their fat mass by nearly 300 percent over the course of about four months. 

Half the mice, including mice on both the healthy and unhealthy diets, were given exercise wheels.

The findings showed mice that had been exposed to the fast food diet but exercised showed suppression in body weight gain and fat mass accumulation and were protected against the accumulation of senescent cells. 

"It doesn't mean that we need to be marathon runners but we need to find ways to increase our habitual activity levels to stay healthy and prevent processes that drive ageing and ageing-related diseases," LeBrasseur noted.​

​New York, March 15 (IANS) Forget the toxic material lithium as researchers from the Massachusetts Institute of Technology (MIT) have come up with an alternative system for generating electricity which harnesses heat and uses no metals or toxic materials for powering smartphones or cars, even deep space missions.

The new approach is based on a discovery announced in 2010 by Michael Strano, the Carbon P. Dubbs professor in chemical engineering at the MIT, and his co-workers.

A wire made from tiny cylinders of carbon known as carbon nanotubes can produce an electrical current when it is progressively heated from one end to the other, for example, by coating it with a combustible material and then lighting one end to let it burn like a fuse.

Now, Strano and his team have increased the efficiency of the process more than a thousandfold and have produced devices that can put out power that can be produced by today's best batteries. 

The researchers, however, caution that it could take some years to develop the concept into a commercialisable product.

“It's actually remarkable that this [phenomenon] hasn't been studied before. The latest experiments show good agreement between theory and experimental results, providing strong confirmation of the underlying mechanism,” said Strano in a paper published in the journal Energy & Environmental Science.

Already, the device is powerful enough to show that it can power simple electronic devices such as an LED light. 

Unlike batteries that can gradually lose power if they are stored for long periods, the new system should have a virtually indefinite shelf life. 

That could make it suitable for uses such as a deep-space probe that remains dormant for many years as it travels to a distant planet and then needs a quick burst of power to send back data when it reaches its destination.

Basically, the effect arises as a pulse of heat pushes electrons through the bundle of carbon nanotubes, carrying the electrons with it like a bunch of surfers riding a wave.

The improvements in efficiency, Strano says, "brings [the technology] from a laboratory curiosity to being within striking distance of other portable energy technologies," such as lithium-ion batteries or fuel cells. 

In their latest version, the device is more than one percent efficient in converting heat energy to electrical energy, the team reports, which is "orders of magnitude more efficient than what's been reported before." 

In fact, the energy efficiency is about 10,000 times greater than that reported in the original discovery paper.

“It took lithium-ion technology 25 years to get where they are” in terms of efficiency, Strano pointed out, whereas this technology has had only about a fifth of that development time. ​

​New York, March 17 (IANS) Researchers have developed a high-tech, food-tracking necklace that will alert you about the unique sounds that foods make as you bite, grind and swallow them.

Each food as it's chewed has its own unique sound and the device can help people suffering from diabetes, obesity, bowel disorders and other ailments by enabling them to better monitor their food intake and improve how they manage their conditions.

“There is no shortage of wearable devices that tell us how many calories we burn but creating a device that reliably measures caloric intake isn't so easy,” said Wenyao Xu, assistant professor of computer science at University at Buffalo.

Xu is creating a library that catalogues the unique sounds that foods make as we eat.

The library is part of a software package that supports “AutoDietary”, a necklace being developed by Xu and researchers at Northeastern University in China.

“AutoDietary” is like Fitbit and other wearable devices. Only instead of tracking burned calories, it monitors caloric intake - in other words, what we eat - at the neck.

AutoDietary wraps around the back of the neck like a choker necklace.

A tiny high-fidelity microphone -- about the size of a zipper pull -- records the sounds made during mastication and as the food is swallowed.

That data is sent to a smartphone via Bluetooth where food types are recognised.

The study, published in the IEEE Sensors Journal, describes how 12 participants ages 13 to 49 were given water and six types of food: apples, carrots, potato chips, cookies, peanuts and walnuts.

“AutoDietary” was able to accurately identify the correct food and drink 85 percent of the time.

Xu plans future studies to build upon his library by testing different foods and recording the sounds they make.

He also plans to refine the algorithms used to differentiate the foods to improve AutoDietary's ability to recognise what's being eaten.

While promising, a wearable necklace that measures sound has limitations when used alone. For example, it cannot differentiate similar foods such as frosted corn flakes and regular corn flakes. It also can't distinguish the ingredients of complex foods such as soup or chili.

To address these limitations, Xu is planning a biomonitoring device which would complement AutoDietary.

The device is under development but it would be activated once the necklace recognises that the user is eating a general category of food.​

London, March 15 (IANS) Researchers have presented a new model for what dark matter might be, a discovery that can lead scientists to invisible dark matter that is all around us yet no one has ever seen it and no one knows what it really is.

Physical calculations state that approximately 27 percent of the universe is dark matter. Only five percent is the matter of which all known materials consist: from the smallest ant to the largest galaxy.

For decades, researchers have tried to detect this invisible dark matter.

“Maybe it's because we have looked after dark particles in a way that will never be able to reveal them. Maybe dark matter is of a different character and needs to be looked for in a different way,” explained Martin Sloth, associate professor at University of Southern Denmark.

For decades, physicists have been working on the theory that dark matter is light and therefore interacts weakly with ordinary matter.

This means that the particles are capable of being produced in colliders.

This theory's dark particles are called weakly-interacting massive particles (WIMPs), and they are theorised to have been created in an inconceivably large number shortly after the birth of the universe 13.7 billion years ago.

“But since no experiments have ever seen even a trace of a WIMP, it could be that we should look for a heavier dark particle that interacts only by gravity and thus would be impossible to detect directly,” said Sloth.

Sloth and his colleagues call their version of such a heavy particle a PIDM (Planckian Interacting Dark Matter) particle.

Together with postdoc McCullen Sandora from CP3-Origins and postdoc Mathias Garny from CERN, Sloth now presents a new model for what dark matter might be in a paper published in the journal Physical Review Letters.
In their new model, they calculated how the required number of PIDM particles could have been created in the early universe.

“It was possible, if it was extremely hot. To be more precise the temperatures in the early universe must have been the highest possible in the Big Bang theory,” added Sloth.

“If the universe indeed was as hot as calculated in our model, several gravitational waves from the very early childhood of the universe would have been created. We might be able to find out in the near future,” he pointed out.

With this, Sloth refers to a number of planned experiments around the world that will be able to detect signals from very early gravitational waves.

“If these experiments do not detect such signals, then our model will be falsified. Thus gravitational waves can be used to test our model,” he added.

More than 10 different experiments are planned.

The team aims to measure the polarisation of the cosmic background radiation, either from the ground or with instruments sent up in a balloon or satellite to avoid atmospheric disturbances.​

London, March 17 (IANS) Adults between 40 and 69 years of age can draw significant health benefits by using public transport, walking and cycling to work as these are linked to reductions in Body Mass Index (BMI) and percentage body fat compared with those who commute by car, say researchers.

"We found that, compared with commuting by car, public transport, walking and cycling or a mix of all three are associated with reductions in body mass and body fat percentage even when accounting for demographic and socio-economic factors," said study author Ellen Flint from London School of Hygiene and Tropical Medicine.Many people live too far from their workplace for walking or cycling to be feasible, but even the incidental physical activity involved in public transport can have an important effect.
The study, published in the journal Lancet Diabetes and Endocrinology, looked at data from over 150,000 individuals from Britian's Biobank data set -- an observational study of 500,000 individuals aged between 40 and 69 in Britain.
The researchers saw the strongest associations for adults who commuted via bicycle compared to those who commute via car. For the average man in the sample (age 53 years; height 176.7cm; weight 85.9kg), cycling to work rather than driving was associated with a weight difference of 5kg. 
For the average woman in the sample (age 52 years; height 163.6cm; weight 70.6kg), the weight difference was 4.4kg.After cycling, walking to work was associated with the greatest reduction in BMI and percentage body fat, compared to car users. For both cycling and walking, greater travelling distances were associated with greater reductions in BMI and percentage body fat.

The link between active commuting and BMI was independent of other factors such as income, area deprivation, urban or rural residence, education, alcohol intake, smoking, general physical activity and overall health and disability.​

​London, March 14 (IANS) Using the full power of the Very Large Telescope Interferometer (VLTI) at ESO's Paranal Observatory in Chile, a team of astronomers has recorded sharpest view ever of dusty disc around an ageing star, suggesting that discs around ageing stars are similar to those around young ones.

As they approach the ends of their lives, many stars develop stable discs of gas and dust around them. 

These discs resemble those that form planets around young stars. Till date, astronomers have not been able to compare the two types, formed at the beginning and the end of the stellar life cycle.

Michel Hillen and Hans Van Winckel from the Instituut voor Sterrenkunde in Leuven, Belgium targeted an old double star lying about 4000 light-years from Earth in the southern constellation of Vela (constellation) 

This double star consists of a red giant star, which expelled the material in the surrounding dusty disc, and a less-evolved more normal star orbiting close to it.

“By combining light from several telescopes of the Very Large Telescope Interferometer, we obtained an image of stunning sharpness. The resolution is so high that, for comparison, we could determine the size and shape of a one euro coin seen from a distance of 2,000 km,” said Jacques Kluska, team member from Exeter University in Britain.

The inner edge of the dust ring, seen for the first time in these observations, corresponds very well with the expected start of the dusty disc.

The team found that discs around old stars are very similar to the planet-forming ones around young stars. 

Whether a second crop of planets can really form around these old stars is yet to be determined but it is an intriguing possibility.

“The observations open a new window to study the physics of these discs as well as stellar evolution in double stars,” Winckel said. ​

New York, March 15 (IANS) Expenses during weddings -- and even at funerals -- can be exploitative, say researchers, adding that people do not think twice before spending on happy or solemn occasions while buying an engagement ring, desserts for a birthday party or even cremation urns.

"People's buying behaviour changes when they're making purchases out of love because it feels wrong to engage in cost-saving measures," said lead author Peter McGraw from University of Colorado Boulder.People abandon cost-saving measures when it comes to sentimental buys because they want to avoid having to decide what is the right amount of money to spend on a loving relationship, McGraw added in the paper published in the journal of Judgment and Decision Making. 

The study involved nearly 245 participants and the team asked attendees at a wedding show about their preference between two engagement rings. The attendees nearly always chose the more expensive ring when deciding between a more expensive ring with a bigger carat and a less expensive ring with a smaller carat.

Even when they identify a less expensive alternative to be equally desirable, people choose the more expensive of two items. They also avoid searching for lower prices and negotiating better prices when the goods they're buying are symbolic of love, the researchers explained."The loss of savings can really add up and put people in compromising financial situations," McGraw stated. ​

New York, March 13 (IANS) An enhanced diet is likely to help curb hearing loss due to genetic abnormality that is most commonly responsible for childhood deafness, new research suggests.

A study found that an antioxidant regimen of beta carotene (precursor to vitamin A), vitamins C and E and magnesium helped slow progression of hereditary deafness in mice, with a deletion in Connexin 26 gene -- a protein found on the gene and the most common cause of innate hearing loss.

Connexin 26 alterations are responsible for at least 20 percent of all genetic hearing loss and 10 percent of all childhood hearing loss.

"Our findings suggest that a particular high dose of mineral and vitamin supplements may be beneficial to one genetic mutation," said one of the authors Yehoash Raphael, professor at the Michigan University.

But, the enhanced diet had the opposite effect on another altered mouse modelling with auditory neuropathy -- a rare type of hearing loss.

The negative outcome in this mouse model suggested that different mutations might respond to the special diet in different ways, the researchers noted.

Mice in the study, published in the journal Scientific Reports, received the antioxidant regimen post-natally and in the womb in separate experiments.

In the Connexin 26 mouse model, the enhanced diet was associated with a slower progression of hearing loss and small but significant improvement in hearing thresholds.

However, the mice with auditory neuropathy experienced the opposite outcome, showing accelerated progression of deafness following the diet.

The research follows a case study University of Michigan published in 2015 in which the same nutritional supplements were associated with slowing the progression of deafness for a boy with a Connexin 26 mutation.

Antioxidants have been shown to reduce the impact of oxidative stress in neuronal disorders, cancer, heart diseases and inflammatory diseases.​