Knowledge Update

​New York, March 18 (IANS) A new equation developed by scientists can predict more accurately your walking energy expenditure, thus replacing the leading standardised equations used for close to half a century that were based on the assumption that one size fits all.

"Our new equation is formulated to apply regardless of the height, weight and speed of the walker. It's appreciably more accurate," said Lindsay Ludlow, a researcher at the Southern Methodist University (SMU) in Dallas.

The equation developed by SMU scientists, which was recently described in in the Journal of Applied Physiology, is about four times more accurate for adults and children together, and about two to three times more accurate for adults only, Ludlow said.

"The economy of level walking is a lot like shipping packages -- there is an economy of scale," said Peter Weyand, a study co-author. "Big people get better gas mileage when fuel economy is expressed on a per-pound basis," he added.

The research comes at a time when greater accuracy combined with mobile technology, such as wearable sensors, is increasingly being used in real time to monitor the body's status. 

The researchers note that some devices use the old standardised equations, while others use a different method to estimate the calories burned.​

New York, March 18 (IANS) Having more ideal cardiovascular health is linked with better brain processing speed and is more likely to prevent the decline in brain function that sometimes accompanies ageing, according to a study.

The researchers from the University of Miami and the Columbia University used the American Heart Association's "Life's Simple Seven" definition of cardiovascular health, which includes tobacco avoidance, ideal levels of weight, physical activity, healthy diet, blood pressure, cholesterol and glucose.

"Achieving the health metrics of Life's Simple 7 is associated with a reduced risk of strokes and heart attacks, even among the elderly," said study lead author Hannah Gardener from the University of Miami.

"The finding that they may also impact cognitive, or brain function underscores the importance of measuring, monitoring and controlling these seven factors by patients and physicians," Gardener added.

At the beginning of the study, published recently in Journal of the American Heart Association, 1,033 participants were tested for memory, thinking and brain processing speed.

Brain processing speed measures how quickly a person is able to perform tasks that require focused attention. Approximately six years later, 722 participants repeated the cognitive testing, which allowed researchers to measure performance over time.

The researchers found that having more cardiovascular health factors was associated with less decline over time in processing speed, memory and executive functioning, which is associated with focusing, time management and other cognitive skills.

"In addition, further study is needed to identify the age ranges, or periods over the life course, during which cardiovascular health factors and behaviours may be most influential in determining late-life cognitive impairment, and how behavioural and health modifications may influence cognitive performance and mitigate decline over time," Gardener said.​

​London, March 19 (IANS) A source of cosmic rays radiating energies 100 times greater than those achieved at the largest terrestrial particle accelerator -- the Large Hadron Collider at the European Organisation for Nuclear Research (CERN) -- has been found in the innermost region of our Milky Way galaxy.

The source was revealed after a detailed analysis of the data collected by the H.E.S.S. observatory in Namibia, which was published in the latest issue of the journal Nature. 

H.E.S.S. observatory is being run by an international collaboration of 42 institutions in 12 countries and has been mapping the centre of our galaxy in very high energy gamma rays for over the past 10 years.

"Somewhere within the central 33 light years of the Milky Way there is an astrophysical source capable of accelerating protons to energies of about one petaelectronvolt, continuously for at least 1,000 years," said Emmanuel Moulin from the Saclay Nuclear Research Centre in France. 

Cosmic rays with energies up to approximately 100 teraelectronvolts (TeV)1 are produced in our galaxy by objects such as supernova remnants and pulsar wind nebulae. 

Theoretical arguments and direct measurements of cosmic rays reaching the Earth indicate, however, that the cosmic-ray factories in our galaxy should be able to provide particles up to one petaelectronvolt (PeV)2 at least. 

While many multi-TeV accelerators have been discovered in recent years, the search for the sources of the highest energy Galactic cosmic rays has been unsuccessful.

The electrically-charged cosmic rays are strongly deflected by the interstellar magnetic fields that pervade our galaxy. Their path through the cosmos is randomised by these deflections, making it impossible to directly identify the astrophysical sources responsible for their production. 

Thus, for more than a century, the origin of the cosmic rays has remained one of the most enduring mysteries of science.

In analogy to the "Tevatron" -- the first human-built accelerator that reached energies of 1 TeV -- this new class of cosmic accelerator has been dubbed a "Pevatron."

​Tokyo, March 18 (IANS) Calcium has been known long as good for our bones, but it might also be the key to a good night's sleep, says a new study, unveiling a new theory how sleep works.

The study showed that sleep depends on the activity of calcium inside neurons.

Moreover, it was also revealed that a mechanism regulated by calcium ions is indeed responsible for controlling the sleep duration.

The study, published in the journal Neuron, contributes to the understanding and treatment of sleep disorders like insomania and sleep apnea and other associated neuro-degenerative diseases.

Over a life time the amount of sleep needed gets gradually reduced, in both animals and humans.

Sleep allows the body to recover from the effects of daily life, such as removing waste products from the brain and restoring the immune system, and may use the time to process experiences and lay down long-term memories. 

However, the fundamental reasons for sleep and the mechanisms by which sleep duration is regulated remain largely unknown.

"Although sleep is a fundamental physiologic function, its mechanism is still a mystery," said corresponding author Hiroki Ueda from the University of Tokyo in Japan.

The team developed a computational model of sleep and identified seven genes responsible for causing mice to stay awake or fall asleep. 

The research group then tested their predictions against 21 different genetically modified mouse types.

Out of the 21, seven exhibited significant changes in sleep duration. 

In addition, the research group also showed that the inflow of calcium ions into neurons is required for mice to fall asleep and that pumping calcium ions out of neurons is required for mice to wake up. 

"Sleep is one of the most fundamental physiological functions. From flies to humans, it seems that most animals sleep, but we still know so little about the molecular processes by which sleep duration is regulated," Ueda added. 

In addition to becoming new molecular targets for sleep drugs, the genes we have identified could also become targets for drugs that treat certain psychiatric disorders that occur with sleep dysfunction, the researchers suggested.​

​London, March 19 (IANS) Researchers have found that the blue tit, collared flycatcher and pied flycatcher have the fastest eyesight in the animal kingdom, with their vision being more than twice as fast as humans.

Thought to be the fastest of any vertebrate animal, their remarkable vision system, allows them to see the world around them in slow motion.

“Bird species similar to the blue tit, collared flycatcher and pied flycatcher, both ecologically and physiologically, probably also share the faculty of superfast vision,” said lead researcher Anders Ödeen, lecturer at Uppsala University in Sweden.

The study, published in the journal PLOS ONE, showed that perching birds, or passerines, have eyes with a temporal visual resolution -- precision of a measurement with respect to time -- of up to 146Hz.

It is at least 50Hz faster than any other vertebrate, and well over twice as fast as the 60Hz a human eye can detect, the researchers pointed out adding that this indicates an evolutionary history of natural selection for fast vision in these bird species. 

That the small airborne birds need to detect and track objects whose image moves very swiftly across the retina to be able to see and avoid all branches when they take cover from predators by flying straight into bushes, gives an explanation for their fast vision. 

The findings raise concerns about the welfare of small caged birds, especially those kept in areas with modern low-energy or flickering lighting light, which can cause stress, behavioural disturbances and various forms of discomfort in humans and birds alike.

Yet it appears perching birds may have traded their ultra-sharp vision at the expense of sharpness.

While the record for the sharpest vision still rests with eagles, which can detect finer details than any other animal, perching birds can only see in low resolution.

For the study, the team trained wild-caught birds to receive a food reward by distinguishing between a pair of lamps, one flickering and one shining a constant light. 

Temporal resolution was then determined by increasing the flicker rate to a threshold at which the birds could no longer tell the lamps apart. 

These birds are increasingly often kept in rooms lit with low-energy light bulbs, fluorescent lamps or LED lighting. Many of these flicker at 100 Hz, which is invisible to humans but perhaps not to small birds in captivity.

​Bangkok, March 18 (IANS) Thai hoteliers in major tourist destinations are preparing measures to deal with serious drought this summer, the media reported on Friday. Members of the Thai Hotels Association (THA) are running water-saving campaigns after being warned that this year's drought will be the worst in a decade, The Bangkok Post. "We have asked for cooperation from our member hotels to help save water," said THA president Surapong Techaruvichit. Many hotels, particularly big ones, have their own water reserves and some have already bought water. In Phuket - one of most visited places in the country, the THA reported that hotels have enough water reserves for use until June. According to the Public Works Department, hotel guests use an average of 350 litres of water per day. Normally, people consume 180-200 litres per day. Saving water in Thailand has become a major issue after warnings that many provinces are expected to run out of water for household consumption and other essential use. ​

​Jakarta, March 18 (IANS) Indonesia has waived visa requirements for 79 more countries, expanding the list to 169 visa-free nations as it continues its efforts to boost foreign visitor numbers. President Joko Widodo on March 2 signed a decree granting visa-free entry to tourists who wish to travel in the country for 30 days, said a statement published on the Cabinet Secretary website on Friday."The presidential decree comes into effect once it is ratified, " the statement said, noting that the Legal and Human Rights Ministry authorised it on March 10. According to the statement, Australia is included in the list of countries after the country was mooted three times last year but later the reciprocal issues were dropped over, Xinhua news agency reported.Throughout last year, the Indonesian government expanded the list to 90 from 15 visa-free countries. The government has set a target to attract 20 million foreign tourists annually by 2019 as an effort to boost growth in Southeast Asia's largest economy. Last year alone, 9.73 million tourists visited the Indonesia​

​Beijing, March 18 (IANS) The number of websites in China rose to 4.27 million at the end of last year, new figures revealed on Friday.A total of 620,000 Chinese websites were launched last year, exceeding the number of sites launched during the 2010-2014 period, according to a report released by the Internet Society of China.

​New York, March 18 (IANS) Ever wondered how your working memory functions in the brain? A new study finds that bursts of neural activity take place as the brain holds information in mind.When the mind holds a sentence just read or a phone number that one is about to dial, then the individual is engaging a critical brain system known as working memory.
The new study upends the notion that brain cells associated with information fire continuously and instead reveals that as information is held in working memory, neurons -- nerve cells -- fire in sporadic and coordinated bursts."Your brain operates in a very sporadic, periodic way, with lots of gaps in between the information the brain represents," said one of the lead authors Mikael Lundqvist, postdoctoral researcher at the Massachusetts Institute Of Technology (MIT) in the US.

Our brain actually works in a very periodic fashion, sending packets of information around.These cyclical bursts could help the brain to hold multiple items in working memory at the same time, the researchers explained."By having these different bursts coming at different moments in time, you can keep different items in memory separate from one another," added one of the authors Earl Miller, professor at MIT.
It would be worthwhile to look for this kind of cyclical activity in other cognitive functions such as attention, the researchers suggested in the study, published in the journal Neuron.The team recorded neuron activity in animals as they were shown a sequence of three coloured squares, each in a different location. 

Then, the squares were shown again, but one of them had changed colour. The animals were trained to respond when they noticed the square that had changed colour -- a task requiring them to hold all three squares in working memory for about two seconds.

The researchers found that as the items were held in working memory, ensembles of neurons in the prefrontal cortex were active in brief bursts, and these bursts only occurred in recording sites in which information about the squares was stored. The bursting was most frequent at the beginning of the task, when the information was encoded, and at the end, when the memories were read out.​

​London, March 18 (IANS) Non-steroidal anti-inflammatory drugs (NSAIDs) are often prescribed to treat a variety of painful conditions but popping these pain-killers may be putting you at the risk of ulcers, increased blood pressure and heart problems, warns a new study.

"It's been well known for a number of years that newer types of NSAIDs -- what are known as COX-2 inhibitors -- increase the risk of heart attacks," said Morten Schmidt from Denmark's Aarhus University, who was in-charge of the study. 

"For this reason, a number of these newer types of NSAIDs have been taken off the market again. We can now see that some of the older NSAID types, particularly Diclofenac, are also associated with an increased risk of heart attack and apparently to the same extent as several of the types that were taken off the market," Schmidt added.

The study, published in the European Heart Journal, emphasised that arthritis medicine is particularly dangerous for heart patients, and also that older types of arthritis medicine, which have not previously been in focus, also appear to be dangerous for the heart.

"This is worrying, because these older types of medicine are frequently used throughout the western world and in many countries available without prescription," Schmidt noted.

The study was carried out in collaboration between 14 European universities and hospitals. The researchers gathered all research on the use of NSAIDs in patients with heart disease. 

"When doctors issue prescriptions for NSAIDs, they must in each individual case carry out a thorough assessment of the risk of heart complications and bleeding," said professor Christian Torp-Pedersen from Aalborg University. 

"NSAIDs should only be sold over the counter when it comes with an adequate warning about the associated cardiovascular risks. In general, NSAIDs are not be used in patients who have or are at high-risk of cardiovascular diseases," the professor added. 

NSAIDs are not antibiotics and therefore do not help to fight infections caused by bacteria.

These drugs are particularly used in the treatment of disorders related to the muscular and bone system, where they counteract swelling, pain and limitations in movement associated with inflammation.​