Knowledge Update

​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 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.​

​New York, May 26 (IANS) Strong tidal encounters may be responsible for the cracks on icy moons such as Pluto's Charon, Saturn's Dione and Tethys, and Uranus's Ariel, says a study.

Until now, it was thought that the cracks were the result of geodynamical processes, such as plate tectonics, but the new computer model developed by University of Rochester researchers suggests that a close encounter with another body might have been the cause.

By devising and running the model, professor Alice Quillen showed that the tidal pull exerted by another, similar object could be strong enough to crack the surface of such icy moons. 

The key factor in determining if a crack is going to occur is the strain rate, the rate of pull from another body that would have caused the moons to deform at a rate that the top, icy layer could not sustain - leading to cracks, said the study.

The findings will be published in a forthcoming issue of the journal Icarus.

Astronomers have long known that the craters visible on moons were caused by the impact of other bodies, billions of years ago. 

But for every crash and graze, there would have been many more close encounters. 

Quillen also thinks that "it might even offer a possible explanation for the crack on Mars, but that's much harder to model".​

New York, May 26 (IANS) Scientists have discovered that hot interstellar winds powered by supermassive black holes in certain galaxies are fuelling a kind of “galactic warming” that is sapping the ability of these galaxies to form stars.

Over the last few billion years, a mysterious kind of galactic warming has caused many galaxies to change from a lively place where new stars formed every now and then to a quiet place devoid of fresh young stars. 

But the mechanism that produces this dramatic transformation and keeps galaxies quiet has been one of the biggest unsolved mysteries in galaxy evolution.

"These galaxies have the necessary ingredients for forming new stars but they are not doing it -- why," wondered Renbin Yan, assistant professor of physics and astronomy at University of Kentucky in the US.

The researchers named these galaxies "red geysers". They host low-energy supermassive black holes which drive intense interstellar winds. 

These winds suppress star formation by heating up the ambient gas found in galaxies and preventing it from cooling and condensing into stars, the researchers explained.

The study, published in the journal Nature, described the discovery of a red geyser galaxy called “Akira” which has a companion galaxy called "Tetsuo." 

Akira's gravity pulls Tetsuo's gas into its central supermassive black hole, fuelling winds that have the power to heat Akira's gas. 

But because of the action of the black hole winds, Tetsuo's donated gas is rendered inert, preventing a new cycle of star formation in Akira, the researchers explained.

The findings suggest that as with global warming on Earth, galactic warming has long-term consequences for red geyser galaxies -- their gas can no longer form new stars.​

​Beijing, May 27 (IANS) The relaxation of China's family planning policy has led to a drop in the number of children being adopted, a trend that is expected to continue, a media report said on Friday.

"The fall in the number of adoptions is the result of economic growth, improvements to the social welfare system and adjustment of the family planning policy," said an official at the ministry of civil affairs' department of social affairs.

"People's attitude to having children has also changed, and fewer parents are abandoning their children, which has resulted in fewer eligible adoptees at welfare institutions," the China Daily reported citing the official as saying.

The number of children adopted by Chinese families has fallen in the past five years. According to the ministry, 29,618 adoption cases were competed in 2010, while last year the number dropped to 17,201.

Tong Xiaojun, director of the China Research Institute of Children and Adolescents, said, "Theoretically, relaxation of the family planning policy will continue to cause a decline in the number of adoptions."

Tong said two types of family have been the main groups seeking to adopt-couples unable to have their own children and those with a single child and wanting a second but could not have one because of the previous family planning policy.

"Many families in China want two children, a boy and a girl, to make a 'perfect family'," Tong said. 

China's Adoption Law states that qualified applicants must not have a child of their own. If they have a child, they can adopt a second if that child is an orphan, abandoned or a child with special needs in a welfare institution.

An official at a child welfare institution in Shanxi province said only five children from his institution were adopted by Chinese families last year.

"There is a lot of pressure on couples raising a child with special needs, especially in China. With the easing of the one-child policy, people have the chance to have their own children... Who will seek to adopt?" he said.

To make it easier for couples to adopt, the civil affairs ministry has been working on amending the Adoption Law since the family planning policy was changed in December 2015.​

​London, May 27 (IANS) Even with a healthy diet, defects in the functioning of the immune system from birth could contribute to a malnourished state throughout life, a study says.

"Our immune system doesn't just fight infection; it affects metabolism, neurological function, and growth, which are things that are also impaired in malnutrition," said lead author Claire Bourke, postdoctoral research assistant at Queen Mary University of London.

"That traditional image of malnutrition - of someone just wasting away - is just the external picture. On the extreme are those height and weight defects," Bourke added.

The study was published in the journal Trends in Immunology.

Consumption of too few calories because of lack of food, an inability to absorb nutrients effectively, or an excess of fat and sugar in the diet can cause defects in immune system.

A dysfunctional immune system can cause a whole range of pro-inflammatory conditions like impaired gut function, weakened responses to new infection as well as a high metabolic burden.

Also, it can reduce the numbers of white blood cells, skin and gut membranes that are easier for pathogens to break through and malfunction the lymph nodes.

These altered immune systems could be passed down from generation to generation regardless of the diet. 

It is because that dysfunction is recorded in the DNA through epigenetic marks. This altered immune system may then cause malnutrition even if children have an adequate diet, the researchers explained.

The most common form of undernutrition globally is stunting -- where children fail to achieve their full height potential. 

Targeting immune pathways could be a new approach to reduce the poor health and mortality caused by under- and overnutrition, the researchers suggested.​