Knowledge Update

​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.

​New York, May 28 (IANS) A team of US engineers has created the world's fastest stretchable, wearable integrated circuits -- a technological feat that can revolutionise the Internet of Things (IoT) and high-speed wireless world in the future.

​Washington, May 26 (IANS) Social networking giant Facebook is reportedly planning to close FBX -- an ad exchange that allows advertisers to buy desktop ads, media reports said on Thursday.

​New York, May 26 (IANS) Vampires are real -- at least the amoebae variety -- and they have been around for millions of years, say researchers who found evidence of predation in ancient microbial ecosystems dating back more than 740 million years.

Using a scanning electron microscope to examine minute fossils, the researchers found perfectly circular drill holes that may have been formed by an ancient relation of Vampyrellidae amoebae. 

These single-celled creatures perforate the walls of their prey and reach inside to consume its cell contents. 

"To my knowledge these holes are the earliest direct evidence of predation on eukaryotes," said Susannah Porter, associate professor at University of California, Santa Barbara in the US.

Eukaryotes are organisms whose cells contain a nucleus and other organelles such as mitochondria.

"We have a great record of predation on animals going back 550 million years starting with the very first mineralized shells, which show evidence of drillholes. We had nothing like that for early life -- for the time before animals appear. These holes potentially provide a way of looking at predator-prey interactions in very deep time in ancient microbial ecosystems," she said.

The findings appeared in the journal Proceedings of the Royal Society B.

For the study, Porter examined fossils from the Chuar Group in the Grand Canyon -- once an ancient seabed -- that are between 782 and 742 million years old. 

The holes are about one micrometre (one thousandth of a millimeter) in diameter and occur in seven of the species she identified. 

The holes are not common in any single one species. In fact, they appear in not more than 10 percent of the specimens, the findings showed.

"I also found evidence of specificity in hole sizes, so different species show different characteristic hole sizes, which is consistent with what we know about modern vampire amoebae and their food preferences," Porter said. ​

New York, May 26 (IANS) Scientists have found that one of the most widely prescribed pain and anti-inflammation drugs has potential to slow the growth of cancer.

The study, focused on celecoxib (Pfizer's Celebrex), showed that the drug slows the growth rate of a specific kind of cancer in animal models and suggests the medication could have the same effect on other types of tumours.

The drug targets an enzyme called "cyclooxygenase-2" (COX-2), which is linked to pain and inflammation. 

"Our study shows that COX2 inhibitors do have an effect on the tumor cells," said the study's first author William Guerrant from the Florida campus of The Scripps Research Institute (TSRI) in the US.

"They also have an impact on inflammatory responses that play a role in tumour growth,” Guerrant noted.

The researchers conducted animal studies tracking the effects of celecoxib on the growth of cancer cells from a tumour type known as neurofibromatosis type II (NF2). 

In humans, NF2 is a relatively rare inherited form of cancer caused by mutations in the anti-tumour gene NF2, which leads to benign tumours of the auditory nerve.

Animals received a daily dose of the drug, and tumour growth was followed by imaging.

Analysis of the results showed a significantly slower tumour growth rate in celecoxib-treated models than in controls.

"It's possible that in other cancers these effects might actually be stronger because of the drug's impact on inflammation," Guerrant noted.​