Knowledge Update

New York, April 26 (IANS) Continuing to have social interaction is key to keeping your ears sensitive even in old age, suggests new research.

Hearing socially meaningful sounds can change the ear and enable it to better detect those sounds, the findings showed.

"The ear is modifiable," said one of the researchers Walter Wilczynski, professor at Georgia State University in the US. 

"It's plastic. It can change by getting better or worse at picking up signals, depending on particular types of experiences, such as listening to social signals,” Wilczynski explained.

The researchers studied the phenomenon in green treefrogs. Researchers used green treefrogs because they have a simple social system with only one or two vocal calls. 

In the lab, the experimental group heard their species' specific calls every night for 10 consecutive nights as they would in a normal social breeding chorus in the wild, while the control group heard random tones with no social meaning. 

Then the researchers placed electrodes on the skin near the frogs' ears and measured the response of their ears to sound.

"If frogs have a lot of experience hearing their vocal signals, the ones that are behaviourally meaningful to them, their ear changes to help them better cope with processing those signals," Wilczynski said.

The findings were published in the Journal of Experimental Biology.

The findings could have important implications for elderly people in nursing homes or prisoners in solitary confinement, both of whom have little social interaction. 

"My guess is people who have a lot of experience with our social vocal signal, which is our speech, this probably helps keep their sensory system in a healthy state that helps them pick out those signals," Wilczynski said.

The researchers are unsure, however, how this change in the ear occurs or what particular change has been made, although they believe the modification occurs in the inner ear based on electrophysiological tests.​

Sydney, April 26 (IANS) The elderly are often unable to adjust to new surroundings. This is partly due to the deterioration of a brain circuit that plays a key role in goal-directed learning, a new study conducted on mice has found.

The results revealed that the faulty activation of this brain circuit mixes both the new and old learning in the elderly mice, thus causing impairment in their ability to select the most appropriate action in response to a changing environment that leads to confusion.

"Flexibility issues in ageing have long been described in other navigation and spatial memory tasks. Here we describe a similar flexibility problem but applied to goal-directed action, which of course has more detrimental consequences for everyday life and potentially compromises survival," said J. Bertran-Gonzalez of the University of Queensland in Australia. 

This flexibility problem could constitute a first step towards major motivational decline and, in some cases, seed further cognitive conditions and dementia, the researchers noted in the paper published in the journal Neuron.

The team found that the ability to make choices between distinct courses of action depends on a brain region called the striatum, which is located in the forebrain and associated with planning and decision-making. 

However, it has not been clear whether the age-related decline in striatal function impairs initial goal-directed learning per se or simply prevents the updating of this learning in face of new environmental demands.

Further, this decline in behavioural flexibility was also accompanied by the deterioration of a specific pathway in the brain, called the parafascicular-to-cholinergic interneuron pathway (PF-to-CIN), which resulted in faulty activation of striatal neurons.

Disrupting this pathway in young mice reiterated the behavioural deficits observed in old mice, resulting in interference between old and new action-outcome associations. 

The findings show that the age-related decline in the PF-to-CIN pathway impairs the ability of mice to adjust to environmental changes in goal-directed learning tasks.

For the study, the team placed aged mice in a chamber and trained them to press two levers: one to receive a grain-based food reward, and the other to receive a food pellet that was identical except that it had a sweet taste. 

Then the mice were placed in another box, where they were given unrestricted access to only one of the pellets -- grain-based pellets -- for an hour. 

Immediately afterward, the mice were again placed in the original chamber and allowed to choose between the differently flavoured food pellets and both young and old mice preferred to eat the sweetened food pellets.

The researchers next switched the associations, such that pressing lever one resulted in the delivery of sweetened food pellets, whereas lever two presses yielded grain-flavoured pellets. 

Young mice successfully adjusted to this environmental change, pressing lever one to receive the sweetened food pellet after having gorged on the grain-based food pellets, and vice versa. 

However, old mice became confused and pressed the two levers at similar rates.​

​New York, April 26 (IANS) Children with vision problems not correctable with glasses or contact lenses are twice as likely to have a diagnosis of attention deficit/hyperactivity disorder (ADHD) when compared to peers without such disorders, suggests a study.

"Children with vision problems should be monitored for signs and symptoms of ADHD so that this dual impairment of vision and attention can best be addressed," said the study's led author Dawn DeCarlo from the University of Alabama at Birmingham, the US.

The findings appeared in the journal of the American Academy of Optometry. 

The researchers analysed data on more than 75,000 children (aged four to 17) from the 2011-12 National Survey of Children's Health, conducted by the US Centres for Disease Control and Prevention. 

Parents were asked whether they had ever been told their child had some type of vision problem that was not correctable with standard glasses or contact lenses. 

Examples of such conditions include disorders of eye alignment or eye movement, such as strabismus or nystagmus.

A current diagnosis of ADHD was reported for 15.6 percent of children with vision problems, compared to 8.3 percent of those without vision problems. 

The findings add new evidence that children with vision problems not correctable by glasses or contact lenses have a higher prevalence of ADHD. The association is independent of differences in patient and family characteristics, the study said.​

​Seoul, April 26 (IANS) Hyundai Motor's operating profit fell to the lowest in five years in the first quarter, a regulatory filing showed on Tuesday.

Operating profit was 1.34 trillion won ($1.16 billion) during the January-March period, down 15.5 percent from the same period last year.

​New York, April 26 (IANS) A San Francisco-based startup has raised $17 million to “rehumanise the interaction” between doctors and patients by using the Google Glass eye-wearable device.

Using Google Glass, Augmedix has developed a platform for doctors to collect, update and recall patient and other medical data in real time, technology website TechCrunch reported on Tuesday.

Google Glass is no longer available for consumers but its enterprise business continues to rise especially in the health care sector.

“When you are with doctors without Glass, they are charting and clicking on computers for a lot of the time and not focusing on their patients,” Ian Shakil, CEO of Augmedix was quoted as saying.

​Washington, April 26 (IANS) Nearly two in three Americans said they prefer to save rather than to spend money, setting a new record since 2001, found a Gallup poll.

The research result came on Monday amid concerns that Americans are not spending enough to keep the US economy growing at a healthy pace, Xinhua news agency reported.

​Beijing, April 25 (IANS) China's coal consumption will be around 4.3 billion tonnes by 2020 as the government pushes for cleaner and greener growth despite the slowing economy, the China National Coal Association (CNCA) said on Monday.

Kathmandu, April 25 (IANS) China has emerged as one of the top five bilateral donors to Nepal in fiscal 2014-15 in terms of funds disbursed, Nepal's Finance Ministry said on Monday.

​London, April 26 (IANS) Atmospheric carbon dioxide (CO2) concentration was the major driver behind the global climatic shifts that occurred in the "Eocene epoch" between 53 and 34 million years ago, says a new study.

The results support the view that elevated CO2 was responsible for the extreme warmth of the early Eocene and that CO2 decline was responsible for the subsequent cooling that ultimately led to the establishment of today’s polar ice sheets.

The researchers believe that the findings, published in the journal Nature, could help scientists better predict future climate change.

For the study, the research team developed new records of past CO2 levels by analysing ancient ocean sediments. 

"We cannot directly measure CO2 concentrations from that long ago,” said study lead author Eleni Anagnostou, postdoctoral researcher at University of Southampton in Britain.

"Instead we must rely on indirect ‘proxies’ present in the geological record. In this study, we used the chemical composition of marine fossils preserved in sediments to reconstruct ancient CO2 levels,” Anagnostou noted.

Applying pioneering geochemical techniques - developed at the University of Southampton over the past five years - the team used isotopes of the element boron in the shells as a proxy for pH (a measure of acidity), and used that to determine the atmospheric CO2 levels.

They found that between the early Eocene and the late Eocene, CO2 levels approximately halved. 

Using our current understanding of the relationship between sea surface temperature and CO2 at different latitudes, they also demonstrated that the changes in CO2 concentration can explain the majority of the cooling that occurred.

This research can also be used to gain a better understanding of how the Earth will respond to increasing levels of CO2 in the future, the scientists said.​

​Beijing, April 25 (IANS) China's central bank on Monday pumped more money into the market to ease a liquidity strain.

The People's Bank of China (PBOC) conducted 180 billion yuan ($27.6 billion) of seven-day reverse re-purchase agreements (repo), a process in which central banks purchase