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.
New York, March 17 (IANS) People who frequently check and re-check their smartphone are driven most strongly by uncontrolled impulses and are less apt in delaying gratification, says a study.
Psychologists Henry Wilmer and Jason Chein from Temple University in the US carried out the study to develop better understanding of the impact of smartphone and mobile technology usage to assess the potential problems associated with heavy use.
The researchers gave 91 undergraduate students a battery of questionnaires and cognitive tests.
They indicated how much time they spent using their phones for social media purposes, to post status updates and to simply check their devices.
Each student's tendency to delay gratification in favour of larger, later rewards was also assessed. They were given hypothetical choices between a smaller sum of money offered immediately or a larger sum to be received at a later time.
The results, published in Springer's journal Psychonomic Bulletin and Review2, provided evidence that people who constantly check and use their mobile devices throughout the day are less apt to delay gratification."Mobile technology habits, such as frequent checking, seem to be driven most strongly by uncontrolled impulses and not by the desire to pursue rewards," Wilmer noted.The findings provide evidence that increased use of portable electronic devices is associated with poor impulse control and a tendency to devalue delayed rewards.
"The findings provide important insights regarding the individual difference factors that relate to technology engagement," Chein said.
"These findings are consistent with the common perception that frequent smartphone use goes hand in hand with impatience and impulsivity," he added.
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.
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.
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 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.
New York, March 14 (IANS) Did you buy junk food while grocery shopping instead of healthy food? Researchers, including an India-origin scientist, have found that consumers are concerned about eating a healthy diet but junk food still ends up in the shopping cart.
The findings showed that retailers can design different strategies that meet the demand for and encourage the purchase of healthier products.
"There is a disconnect between what people say they want to eat and what they actually purchase," said study co-author Minakshi Trivedi from University at Buffalo's school of management."Each group we studied made trade-offs on healthy and unhealthy food to varying degrees," Trivedi added.
The researchers analysed two years of scanner data across more than 70 stores of a major US retail chain, along with survey responses from 400 of the chain's shoppers to see if consumers consciously balanced their health concerns with their actual food purchases.
The study, published in the Journal of Retailing, grouped consumers into three segments.
The first group was made up of health-driven buyers. The second group took a more moderate approach to purchasing healthy products and the third group was indifferent to the healthier versions of products.
When faced with healthy or unhealthy choices, the consumer segments showed distinct variations in characteristics, purchasing behaviour and response to price and discounts.
Price had the smallest impact on the health-driven group, where 92 percent of buyers consistently purchased the healthy options.
The moderate group was more price sensitive and likely to balance between healthy and regular versions of products -- about half of the buyers in this group chose the healthy options.
In the third group, consumers were more affected by price and discounts and preferred the regular versions of products as opposed to their healthy alternatives.
"If government agencies want to have any impact in promoting healthy consumption, they need to tailor their strategies to specific behavioural segments," Trivedi added.
New York, March 17 (IANS) In the early stages of Alzheimer's disease, patients are often unable to remember recent experiences. However, a significant research suggests that those memories are still stored in the brain and can be retrieved with a new technique in the near future.
According to neuroscientists including an Indian-origin scientist from the Massachusetts Institute of Technology (MIT), mice in the early stages of Alzheimer's can form new memories just as well as normal mice but cannot recall them a few days later.Furthermore, the researchers were able to artificially stimulate those memories using a technique known as optogenetics, suggesting that those memories can still be retrieved with a little help. Although optogenetics cannot currently be used in humans, the findings raise the possibility of developing future treatments that might reverse some of the memory loss seen in early stage Alzheimer's.
“The important point is that this is a proof of concept. That is, even if a memory seems to be gone, it is still there. It's a matter of how to retrieve it,” said Susumu Tonegawa, director of the RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory.Tonegawa is the senior author of the study which appeared in the journal Nature, and Dheeraj Roy, an MIT graduate student, is the paper's lead author.
The researchers have also shown that they can manipulate these memory traces or engrams to plant false memories, activate existing memories, or alter a memory's emotional associations.To investigate this further, the researchers studied two different strains of mice genetically engineered to develop Alzheimer's symptoms along with a group of healthy mice.All of these mice, when exposed to a chamber where they received a foot shock, showed fear when placed in the same chamber an hour later. However, when placed in the chamber again several days later, only the normal mice still showed fear.
The Alzheimer's mice did not appear to remember the foot shock.
"Short-term memory seems to be normal, on the order of hours. But for long-term memory, these early Alzheimer's mice seem to be impaired," Roy said.
The researchers then showed that while the mice cannot recall their experiences when prompted by natural cues, those memories are still there.
“Directly activating the cells that we believe are holding the memory gets them to retrieve it," Roy noted, adding that “this suggests that it is indeed an access problem to the information, not that they're unable to learn or store this memory”.
“If we want to recall a memory, the memory-holding cells have to be reactivated by the correct cue. If the spine density does not go up during learning process, then later, if you give a natural recall cue, it may not be able to reach the nucleus of the engram cells," Tonegawa explained.
The researchers were also able to induce a longer-term reactivation of the "lost" memories by stimulating new connections between the entorhinal cortex region of the brain and the hippocampus.
“It's possible that in the future some technology will be developed to activate or inactivate cells deep inside the brain, like the hippocampus or entorhinal cortex, with more precision," Tonegawa added.