Knowledge Update

​New York, May 27 (IANS) Researchers, including one of Indian-origin, have discovered that lower levels of a hormone may make teenagers vulnerable to gaining unhealthy weight.

"Our study is the first to look at levels of spexin in the pediatric population," said one of the study authors Seema Kumar from Mayo Clinic Children's Centre in Minnesota, US. 

Potentially tied to weight management, spexin is also believed to have a role in controlling arterial blood pressure as well as salt and water balance.

"Previous research has found reduced levels of this hormone in adults with obesity. Overall, our findings suggest spexin may play a role in weight gain, beginning at an early age," she added.

The study was published in the Journal of Clinical Endocrinology & Metabolism.

The study analysed spexin levels in 51 obese and 18 teenagers of normal weights between ages 12 and 18. The participants had blood samples taken between 2008 and 2010 as part of separate clinical trials.

Researchers tested the blood samples to measure spexin levels. They divided the teenagers into four groups based on their spexin levels. 

Among the participants with the lowest levels of spexin, the odds of having obesity were a little more than five times higher than in the group with the highest levels of the hormone.

"It is noteworthy that we see such clear differences in spexin levels between obese and normal weight adolescents," Kumar said. 

"Since this is a cross-sectional study, more research is needed to explore the physiological significance of spexin, how it may be involved in the development of childhood obesity, and whether it can be used to treat or manage the condition," she added.​

​New York, May 27 (IANS) In order to help you identify between habitual and goal-directed action, your brain's circuits compete for control and make a fine balance between the two actions, an international team of researchers has identified.

They found brain chemicals and neural pathway involved in switching between habitual behaviour and deliberate decision-making -- providing the strongest evidence to date that the brain's circuits for habitual and goal-directed action compete for control. 

"We need a balance between habitual and goal-directed actions. For everyday function, we need to be able to make routine actions quickly and efficiently, and habits serve this purpose," said lead author Christina Gremel from the University of California-San Diego.

"However, we also encounter changing circumstances, and need the capacity to 'break habits' and perform a goal-directed action based on updated information. When we can't, there can be devastating consequences," she added.

The study, published recently in the journal Neuron, worked with a mouse model to demonstrate what happens in the brain for habits to control behaviour.

Gremel said the brain's circuits for habitual and goal-directed action compete for control -- in the orbitofrontal cortex (OFC), a decision-making area of the brain -- and that neurochemicals called endocannabinoids allow for habit to take over, by acting as a sort of brake on the goal-directed circuit.

"Habit takes over when the OFC is quieted," Gremel said.

In the study, since endocannabinoids are known to reduce the activity of neurons in general, the researchers hypothesised that endocannabinoids may be quieting or reducing activity in the OFC and, with it, the ability to shift to goal-directed action. 

They trained mice to perform the same lever-pressing action for the same food reward but in two different environments that differentially bias the development of goal-directed versus habitual actions. 

Like humans who don't suffer from neuropsychiatric disorders, healthy mice readily shifted between performing the same action using a goal-directed versus habitual action strategy. 

To test their hypothesis on the role played by endocannabinoids, the researchers then deleted a particular endocannabinoid receptor. 

Mice missing these receptors did not form habits -- showing the critical role played by the neurochemicals as well as that particular pathway.​

​New York, May 27 (IANS) As the difficulty of making a decision increases, activity in a part of the brain that is crucial to making coherent thoughts also increases, a study says.

Researchers found a strong positive correlation between perceptual difficulty and activity in insular cortex which is generally divided into anterior insula, middle insula, and a posterior insula.

Perceptual decision-making is the process in which sensory information is gathered and used to influence our behaviour. For instance, if a person is driving and suddenly sees an object in front of the vehicle, he or she must decide what action to take, such as whether to slow down or bypass the object.

"This study found the activity of the anterior insulae can predict how well the sensory information is perceived or what the difficulty level of the perceptual task is," said Mukesh Dhamala, associate professor at Georgia State University in the US.

"This research is important because the anterior insulae, along with two nearby brain structures, make up the salience network, and when this network is impaired, it affects the ability to switch between tasks and make coherent thoughts,” Dhamala noted.

“Impairment in this network could possibly be linked to psychiatric illnesses, such as schizophrenia, dementia and autism, so it's essential to learn more about how this brain area should be functioning," he explained.

The findings were reported in the journal Neuroscience.

The study involved 33 people with normal or corrected-to-normal vision and normal neurological history. 

They completed four tasks, in which the researchers manipulated the visual and audiovisual stimuli to create varying degrees of task difficulty.

In all four experimental tasks, researchers found that anterior insulae activity consistently increased with task difficulty.

​London, May 27 (IANS) Have you ever wondered why any talk of giving money to the unemployed often triggers a political storm whereas increase in healthcare costs often earn laurels? The answer, say researchers, can be found deep in our psychology, where powerful intuitions lead us to view illness as the result of bad luck and worthy of help.

People intuitively believe that those who fall ill are unlucky, while unemployed people have brought it on themselves, the study found.

Using techniques to uncover people's implicit intuitions, the researchers explored the fundamental differences behind our attitudes towards unemployment benefits and healthcare.

According to the researchers, the differences may be found in the evolutionary history of our species.

Unemployment came about as a result of the industrialisation, while illness is something the human species has faced for millions of years. 

"For millions of years, a need for health care reflected accidents such as broken legs or random infections. Evolution could therefore have built our psychology to think about illnesses in this way, as something we have no control over,” said one of the researchers Michael Bang Petersen, professor in political science at Aarhus University in Denmark.

“People everywhere seem to have this deep-seated intuition that ill people are unfortunate and deserve to be helped," he noted.

The researchers did research in Denmark, the US and Japan and found that everywhere people intuitively believed that people who fall ill are unlucky, while unemployed people have brought it on themselves.

"When it comes to healthcare, everyone seem united in the belief that people who are ill are unlucky and need help,” he said.

The findings appeared in the American Journal of Political Science.

“This means that the policies in the areas of health care and unemployment are very different, as we all more or less agree on the goal in healthcare, while we deeply disagree on whether or not unemployed people deserve help," the researcher said.​

​New York, May 27 (IANS) A team of students has developed an early version of a foot that enables women adjusting to life with a prosthetic limb to wear heels up to four inches high.

"High heels have become an integral part of the female lifestyle in modern society, permeating through all aspects of life -- professional and social," said the authors from Johns Hopkins University who made the prosthetic foot as part of their final senior project in mechanical engineering. 

"For female veterans of the US armed services with lower limb amputations, that seemingly innocuous but so pervasive and decidedly feminine part of their lives is gone," they added.

So, they took up the challenge of creating a foot that adjusts without a separate tool to a range of heel heights, holds position without slipping, supports up to 250 pounds or 114 kg, weighs less than three pounds or 1.3 kg and, of course, is slender enough to accommodate a woman's shoe.

They tried a balloon in the heel to give it spring or "energy return", as engineers say. That didn't work. 

They tried a mousetrap spring but that didn't work either. Then they tried a sideways sandwich of 23 slender titanium plates to form the foot itself but that was too heavy and not springy. 

A 20-layer carbon fibre footplate failed a stress test, but a 28-layer version worked, forming the base of the foot which the team now calls the "Prominence".

They built a heel-adjustment mechanism with two interlocking aluminum disks. It opens and closes with an attached lever at the ankle. 

For the ankle, they used an off-the-shelf hydraulic unit that enables a smooth gait and flexing at the sole.

Alexandra Capellini, a Johns Hopkins University junior who lost her right leg to bone cancer as a child, tried the foot with a flat shoe and liked it.

The design is still in progress. It will take time to assess the commercial appeal and potential of the "Prominence", including the question of whether anything the team created could qualify for a patent.​

​New York, May 28 (IANS) People have always wondered why many birds lay bright blue eggs. Researchers have now shown that the colour could protect the embryo from harmful sunlight, including dangerous ultraviolet (UV) radiation.

David Lahti of the City University of New York and Dan Ardia of Franklin & Marshall College tested the hypothesis that pigmentation might help an egg strike a balance between two opposing and potentially damaging effects of the sun - light transmission into light-coloured eggs, and heating up of dark-coloured eggs. 

As predicted, more intensely blue eggshells shielded the interior from light, including dangerous UV radiation, but more intense colour also caused eggs to absorb more light and heat up, which can be even more dangerous in brighter environments. 

These two patterns - termed by the authors "pigment as parasol" and the "dark car effect" --combined with a knowledge of the nesting behaviour and habitats of birds, can lead to predictions as to why the eggs of some birds vary across species from blue to white. 

Darker eggs are predicted in moderate light to shield the embryo, but in brighter nests the dangers of egg heating predict lighter coloured eggs. 

Whereas camouflage from predators is still probably the single most important factor governing the evolution of dull and mottled egg colours, for the brighter colours the biophysical evidence points to the sun, the study said.

The findings appeared in the journal The American Naturalist.​

​Beijing, May 29 (IANS) China will launch its first experimental quantum communication satellite in July, according to the Chinese Academy of Sciences (CAS) on Friday.

This will be the first quantum communication through a satellite in the world, Xinhua news agency quoted Pan Jianwei, professor with University of Science and Technology of China as saying.

Quantum communication boasts ultra-high security as a quantum photon can neither be separated nor duplicated. It is hence impossible to wiretap, intercept or crack the information transmitted through it, said Pan.

Chinese scientists have taken five years to develop and manufacture the first quantum satellite. It will be transported to Jiuquan Satellite Launch Center in June, according to the CAS. ​

​London, May 29 (IANS) Harry Potter undergoes two magical biological transformations in the popular eight-film series based on the stories and characters created by British author J.K. Rowling.

Natural sciences students have now put these 'mysterious' powers to the test to find out whether these are actually scientifically feasible.

In "Harry Potter and the Goblet of Fire", Harry passes the second 'Triwizard' task by consuming 'Gillyweed', which allows him to breathe underwater by causing gills to grow on his neck.

To check the feasibility of Harry surviving with home-grown gills, University of Leicester students Rowan Reynolds and Chris Ringrose estimated the gills to be approximately 60cm2 in surface area based on their appearance in the film.

Taking into account the oxygen content of the 'Black Lake' and the maximum oxygen use of swimming, they then examined Harry's weight, suggesting that if he had a normal BMI and the average height of a 14-year-old boy, he would need to process 443 litres of water at 100 percent efficiency per minute for every minute he was underwater.

This would mean the water would have to flow at 2.46 metres per second -- twice the velocity of normal airflow and therefore far faster than he could inhale and exhale, causing him to suffocate, the students said in a paper for the Journal for Interdisciplinary Science Topics.

Moreover, Harry is seen swimming with his mouth closed, which is not how gills work -- the students suggest that if Harry were to open his mouth to allow water into his throat and out through the gills, it may be plausible he could breathe underwater.

By keeping his mouth shut, however, he would not be able to extract sufficient oxygen for survival, and as a result would lose his title as 'The Boy Who Lived' quite quickly after suffocating, the study concluded.

In a separate study, students Leah Ashley, Chris Ringrose and Robbie Roe set out to test the feasibility of Skele-Gro, a potion which repair broken bones.

In "Harry Potter and the Chamber of Secrets", Harry's tense Quidditch match against Slytherin results in one of his arms being broken by a rogue bludger.

After his broken bones are removed, Harry is given a dose of Skele-Gro to grow bones that are missing.

The team calculated how the rate of normal bone growth compares to this accelerated growth, and how much energy Skele-Gro would need to provide in order to rebuild Harry's broken arm.

The students calculated the time taken for Harry to regrow all the bones in his arm with Skele-Gro as being at least 90 times quicker than is possible in real-world bone regeneration.

As Harry's recovery with Skele-Gro takes approximately 24 hours and there is no mention of him eating during recovery, Skele-Gro has the capacity to supply the additional 133,050 kcal worth of energy required by the body to regenerate bones without causing any negative side effects, a power output of 6,443 W.

The students concluded that Skele-Gro must therefore contain unexplained magical properties that allow it to hold such a vast amount of energy and be able to apply it in a short period of time.

Both the studies reveal that a little magic might indeed be required in both situations to make them scientifically feasible​

​London, May 29 (IANS) Minor irregularities in the heartbeat are indicative of a healthy body, scientists said at Technical University of Munich. They have developed a new method of correlating heartbeat with life expectancy.

While in the majority of earlier studies the full breathing cycle was correlated to the heart rate, the team now focused on exhaling and specifically on the moment when the heart rate would normally be reduced again.

"With our approach, you might say we are surgically selecting the moment when the decisive events take place," one of the researchers, Georg Schmidt, said.

"Our method produces a far more specific picture of the functional condition of the body," said Daniel Sinnecker, primary author of the study.

Within the framework of the study, published in the Journal of the American College of Cardiology, breathing cycles and heart beat rhythms of close on 950 heart attack patients were measured shortly after a heart attack.

The data was analysed to find respiratory sinus arrhythmia, which may be translated as a "breathing-induced irregularity in the sinus node, the bundle of nerve fibers controlling the heart beat".

The test persons were re-examined every six months over a five-year period.

They found that heart attack patients with less pronounced arrhythmia had a higher risk of dying within the period of observation.

Examined persons with only minor arrhythmia were five times more at risk of dying over the five-year period than people with higher breathing-related fluctuations.

The researchers are confident that the new method may soon be widely applied in medical practice.

"We are quite close to everyday application since, by and large, the development of the method is complete," Schmidt said.

The technical hurdles are few since it is no longer necessary these days to measure breathing rate in addition to heart beat, a modern ECG unit would basically suffice, the researchers explained.

"Even the general practitioner could therefore within ten minutes record sinus arrhythmic activity," Schmidt said.

The method may be fruitfully applied in more than 80 percent of the cases, Schmidt noted.

Irrespective whether the examined patients had recently suffered a heart attack, it could be used in combination with other indicators to assess the health risk, the researchers said.​

​New York, May 28 (IANS) Without user self-reporting, beacons or other supplemental location technology, a mobile device location is only accurate to within about 93 feet, a study has found.