Knowledge Update

​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.​

​New York, May 27 (IANS) NASA has released a video to highlight its 'Twins Study' that investigates metabolic changes in retired US astronaut Scott Kelly and his twin brother Mark.

The video titled "Metabolomics: You Are What You Eat" and sixth in the mini-series of eight videos, provides a broad overview of ongoing Twins Study research on the International Space Station and the importance of the metabolome -- the collection of an individual's metabolites, NASA's Human Research Programme said on Thursday.

Metabolites are key small molecules. They're the chemicals in the body to let you do all the things you do. It's all these things that give you energy, like glucose. They let you move, think, and digest your food.

Using a mass spectrometer, researchers can analyse blood and urine for secreted metabolites. 

By following Scott and Mark Kelly both in space and on Earth, scientists can see a collection of changes occurring. Some chemicals are indicative of high stress but other chemicals are unknown. 

It is hoped that the Twins Study will show which stress molecules get activated at which times and what other kinds of metabolites are present and active. 

Identical twins share the same fertilised egg, thus, share similar genes. Because of similarities, researchers can focus on the metabolic changes.

Researchers believe that diet definitely impacts a person's metabolites. They can see which foods cause what kinds of metabolic changes and how that evolves over time. 

The study could be helpful for researchers creating recommendations to protect the health of astronauts embarking on long-duration missions, such as a journey to Mars, as well as benefit humans on the Earth.​

​London, May 27 (IANS) Adolescents and young adults have a lower chance of surviving some common types of cancer than children, finds a new study on cancer survival across Europe.

"The good news is that the number of children, adolescents and young adults surviving for at least five years after diagnosis has risen steadily over time in Europe," said lead author Annalisa Trama from The National Institute of Cancer in Milan, Italy. 

"However, we found that adolescents and young adults still tend to die earlier than children for several cancers common to these age groups, particularly blood cancers like leukaemias and non-Hodgkin's lymphoma (NHL)," Trama added.

According to researchers, the variations in survival rates between both age groups are due to a number of factors including delays in diagnosis and treatment, a lack of treatment guidelines and clinical trials specifically for teenagers and young adults, as well as differences in the biology of some cancers.

For the study, published in the journal The Lancet Oncology, the team analysed data from 27 European countries on nearly 56,505 cancer cases in children, 3,12,483 in adolescents and young adults and 35,67,383 in adults. 

The findings showed that overall, survival was significantly worse for adolescents and young adults compared with children for eight relatively common cancers affecting both age groups -- acute lymphoid leukaemias, acute myeloid leukaemias, Hodgkin's lymphoma, Non-Hodgkin lymphoma (NHL), astrocytomas (type of brain tumour), Ewing's sarcoma of bone, rhabdomyosarcoma (cancer of soft tissue like muscle) and osteosarcoma (the most common type of bone cancer).

But for cancers with a better prognosis, the five-year survival rates were found to be higher in teenagers and young adults at 82 percent compared with 79 percent in children.

Further, adolescents and young adults were found to have a survival advantage over adults for almost all major cancers affecting both age groups, supporting the idea that younger patients with few other illnesses are likely to fare better than older patients.

However, adolescents and young adults were found at a survival disadvantage for breast and prostate cancer. 

"This reflects the fact that younger women often present with larger, higher-grade cancers that are more advanced, and that prostate disease tends to be more aggressive in younger men," Trama noted.​

London, May 28 (IANS) Is your toddler struggling to learn a language? If so, using words that have repetitive syllables rather than mixed sounds may help him or her to learn language faster, a study suggests.

The findings showed that children are better at grasping the names of objects with repeated syllables, over words with non-identical syllables.

"This is the first evidence to show that infants have a repetition bias in learning new words,” said lead researcher Mitsuhiko Ota from University of Edinburgh in Britain. 

This may be the reason why words or phrases, such as 'train' and 'good night', have given rise to versions with repeated syllables, such as choo-choo and night-night

Such words are easier for infants to learn, and may provide them with a starter point for vocabulary learning.

“The study also shows that there may be a good reason why in so many cultures across the world, existing adult words and expressions are replaced by words with repeated syllables in baby-talk vocabulary. Some examples could be tum-tum, mama, dada, din-din and wee-wee," Ota added.

For the study, published in the journal Language Learning and Development, the team assessed language learning behaviour among 18-month-olds in a series of visual and attention tests using pictures on a computer screen of two unfamiliar objects.

The two objects were named with made-up words, which were communicated to the infants by a recorded voice - one with two identical syllables, for example neenee, and the other without repeated syllables, such as bolay.

The infants were then tested for their recognition of each made-up word. 

Recordings of their eye movements showed they looked more reliably at the object labelled with repeated syllables, than the other object.​

​New York, May 27 (IANS) A new method developed by two Indian-origin engineers can provide important insights into how exactly a machine-learning algorithm comes to a decision to either accept or reject your loan application - something that usually remains a mystery.

​New York, May 26 (IANS) A team of researchers has listed some web apps that help people work collaboratively and complete shared tasks online, often over long distances.

The results noted the evaluation of 20 popular apps for usability, including Google Drive, Skype, Doodle Poll, Gmail, Windows Hotmail, CoSketch and DropBox.

​Tokyo, May 26 (IANS) The world's first robotic mobile phone RoBoHon, a pocket-size walking and dancing robot, started sale on Thursday in Japan.

The human-shaped smartphone, developed by Japanese electronics company, Sharp and engineer Tomotaka Takahashi, inventor of the first robot astronaut 'Kirobo', went on