Knowledge Update

​New York, Sep 28 (IANS) In a groundbreaking feat, a team of biomedical engineers has successfully implanted lab-grown artificial blood vessels in young lambs which are capable of growth within the recipient.

If confirmed in humans, these new vessel grafts would prevent the need for repeated surgeries in some children with congenital heart defects, said the team from the University of Minnesota.

"This might be the first time we have an 'off-the-shelf' material that doctors can implant in a patient and it can grow in the body," said professor Robert Tranquillo from the University of Minnesota Department of Biomedical Engineering.

"In the future, this could potentially mean one surgery instead of five or more surgeries that some children with heart defects have before adulthood," he added.

One of the greatest challenges in vessel bioengineering is designing a vessel that will grow with its new owner.

In this study, Tranquillo and his colleagues generated vessel-like tubes in the lab from a post-natal donor's skin cells and then removed the cells to minimise the chance of rejection.

When implanted in a lamb, the tube was then repopulated by the recipient's own cells allowing it to grow.

To develop the material for the study, researchers combined sheep skin cells in a gelatin-like material, called fibrin, in the form of a tube and then rhythmically pumped in nutrients necessary for cell growth.

The researchers then used special detergents to wash away all the sheep cells, leaving behind a cell-free matrix that does not cause immune reaction when implanted.

The vessel graft replaced a part of the pulmonary artery in three lambs at five weeks of age.

The implanted vessels were soon populated by the lambs' own cells, causing the vessel to bend its shape and grow together with the recipient until adulthood.

"What's important is that when the graft was implanted in the sheep, the cells repopulated the blood vessel tube matrix," Tranquillo noted.

"If the cells don't repopulate the graft, the vessel can't grow. This is the perfect marriage between tissue engineering and regenerative medicine where tissue is grown in the lab," he added in a paper published in the journal Nature Communications.

At 50 weeks of age, the sheep's blood vessel graft had increased 56 per cent in diameter and the amount of blood that could be pumped through the vessel increased 216 per cent.

No adverse effects such as clotting, vessel narrowing or calcification were observed.

Tranquillo said the next step is talking with doctors to determine the feasibility of requesting approval from the US Food and Drug Administration (FDA) for human clinical trials within the next few years.

​New Delhi, Sep 25 (IANS) With Yahoo announcing a massive data breach last week where 500 million of its user accounts were compromised in 2014, experts feel that the trick to avoid email account hacking is to use really long random string for a password.

​London, Sep 25 (IANS) Indian multinational Tata Steel is set to begin crucial talks with trade union representatives of its British steelworks to settle the deadlock over a 15 billion pound pension scheme for its workers, British media reported on Sunday.

​London, Sep 25 (IANS) Strong cross-societal cliches about people from different nations may influence decisions and willingness to cooperate, finds a study.

For the study, published in the journal Proceedings of the National Academy of Sciences, the researchers invited 1,200 people from Germany, India, Israel, Japan, Mexico and the US to take part in an online game with one another.

To learn about how the participants formed their expectations, they were subsequently asked about how they assessed their co-players -- on the basis of criteria for assuming a willingness to cooperate: Trustworthy, friendly, generous or likeable. 

The researchers also asked the participants about other characteristics like to specify how attractive, spiritual, sociable, sporty and wealthy they considered the others to be.

The study revealed that the players hold strong beliefs that are influenced by nation-specific cliches about the behaviour of their co-players. 

The researchers had already shown in previous study how differently US Americans assess the willingness to cooperate of partners from other countries. For example, they expect a high degree of willingness from the Japanese, but a very low level of willingness from Israelis or Indians. 

Paradoxically, people from Israel assume a very high level of cooperation from partners in the US and cooperate for their part. The Japanese are essentially more pessimistic about the cooperative behaviour of other nationalities; Germany ranks at an average level in this regard for the Japanese.

The participants thus behave according to stereotypes, even though these ultimately prove to be false and actually correlate negatively with reality. This prompted the researchers to compare the expected contributions with the actual results. 

Participants, for instance, often expect very cooperative behaviour from the Japanese in the test, which ultimately is not the case - most likely because the Japanese do not expect a great deal of cooperation from others. 

These stereotypes have a negative effect on the Israelis - a lower level of willingness to cooperate is generally expected from them, even though they are fully prepared to share.

"There can often be some truth in stereotypes, but if we unjustly judge people wrongly, then our responses are also wrong. This alone should make us more aware," said Angela Rachael Dorrough, Researcher at the Max Planck Institute for Research on Collective Goods.

​New York, Sep 25 (IANS) A method to measure the limit to which human skin can be stretched has been developed by US researchers, which could help to grow new skin for burn victims.

"Surgeons use a variety of techniques to grow skin for tissue expansion procedures designed to grow skin in one region of the body so that it can be auto-grafted on to another site (sometimes used for burn victims)," said Guy German, Assistant Professor at the Binghamton University in New York, US.

This procedure stretches the skin, typically, by inflating a balloon with air or silicone under the surface. Skin grows more in regions where it is stretched -- during pregnancy, for instance -- but stretch it too much and the tissue might break.

"Our predictive technique could be employed in this field as a method of predicting the limit to which the skin could be stretched," German added.

The outermost layer of skin, the stratum corneum, regulates water loss from the body and protects underlying living tissue from germs and the environment, in general. It is pretty tough, protecting the body from extreme temperatures, rough surfaces, and most paper edges.

In the study, assuming that the skin is smooth and without major cracks, the researchers looked how the toughness of skin varied significantly in relation to its water content. They found dry skin is brittle and easier to break than hydrated skin.

Then, they used advanced imaging to track skin deformation and stretching which, combined with the structure of the skin itself, correlates to where cracks in skin begin.

This can help scientists and doctors predict where fractures may occur in the future, the study said.

They also found that cracks in the skin are not straight; instead they follow topographical ridges of skin, which have triangular patterns.

In addition, the team proved that most fractures propagate along cell-cell junctions rather than breaking the cells themselves. This does not always happen, but it suggests that cell junctions are structurally the weakest points of the skin, they said.

The results could help create new topical medical creams, soaps and cosmetic products. It may also be used in more extreme cases.

This work also sets the stage for a variety of future studies assessing changes in skin composition, environmental pH, or bacterial colonisation on skin's toughness, German noted, in the paper published in the journal Acta Biomaterialia.

New York, Sep 25 (IANS) Although eye wearable device Google Glass did not take off as it was projected to be, the device is helping Emergency Medical Technicians (EMTs) and paramedics communicate with ease with doctors during emergencies.

The augmented-reality headset is being used by paramedics and EMTs assessing patients and them consult with surgeons and doctors at the hospital in real time, Popular Science reported.

"During disasters, emergency rooms typically get overwhelmed. So when truly injured patients show up later, we have nowhere to put them," said Peter Chai, emergency medical physician at the University of Massachusetts' Medical School (UMMS).

UMMS is set to organise a drill this fall with first responders wearing Google Glass to see if it improves emergency assessment.

The university will also deploy a drone equipped with heat sensors to help find patients and determine which ones need the most urgent attention.

Stanford University is also using Google Glass to help kids with autism.

The university's Autism Glass Project provides families with facial recognition software that helps interpret facial expressions.

New York, Sep 25 (IANS) In a study having far-reaching implications like helping preserve the environment through reducing excess carbon expelled by humans into the atmosphere, an international research team has catalogued surface ocean viruses treble the number of those known hitherto.

The study, led by scientists from Ohio State University, in the US, including University of Michigan biologist Melissa Duhaime, catalogues triple the number of known types of viruses living in waters around the globe and is expected to provide scientists a better idea about what role they play in nature.

Microbes in the oceans make half of the oxygen humans breathe, making viruses that infect these microbes particularly important.

"Our work not only provides a relatively complete catalogue of surface ocean viruses, but also reveals new ways that viruses modulate greenhouse gases and energy in the oceans," said lead author Simon Roux of Ohio State.

The researchers processed viral samples collected by scientists aboard two exploration ships to Antarctica.

Roux analysed genetic information from those samples to catalogue 15,222 genetically distinct viruses and group them into 867 clusters that share similar properties.

"Ten years ago I would never have dreamed that we could establish such an extensive catalogue of ocean organisms around the world," added Matthew Sullivan, the study's senior author and an associate professor of microbiology.

"Scientists around the world are revealing how microbes impact our bodies, soil, air and oceans. As we improve our ability to study viruses, we're seeing the role viruses play in these microbial functions," Sullivan noted.

"These findings have implications far beyond ocean viral diversity and will help us better understand microbial diversity on a global scale," added Duhaime in a paper published online in the journal Nature.

​London, Sep 26 (IANS) Researching about the the early origins of the common house cat , a new DNA study has found that the felines travelled the world with farmers and Vikings.

The findings showed that there appeared to be two big migration waves of ancient cats -- the first occurred not long after the development of agriculture by humans and the second shortly after the domestication of cats in ancient Egypt approximately 4,000 years ago, said Eva-Maria Geigl, an evolutionary geneticist at the Institut Jacques Monod in France. 

The first wave was the result of agriculture by humans.

Small cats came into contact with the humans as an increased populations of rodents started consuming the grains they grew.

A link between cats in the Fertile Crescent -- a region in the Middle East and other parts of the Mediterranean, confirmed this, the researchers said. 

The second wave occurred several thousand years later and appeared to be driven by human migrations out of Egypt. 

Due to farmers and seafaring travellers taking cats along with them to reduce rat and mouse populations, cats were found in Egypt and throughout Eurasia as well as parts of Africa.

In addition, the researchers also found that the fierce Vikings apparently had a soft spot for little kitties and one of them was found buried alongside its master in a common grave site that was dated back 1000 years. 

To learn more about the ancestry of the cat, the researchers obtained mitochondrial DNA samples of 209 cats from multiple archaeological sites around the world. 

The ages of the remains ranged from approximately 15,000 years ago to just 300 years ago. 

The study was presented at International Symposium on Biomolecular Archaeology 2016 at the Oxford University Museum of Natural History, in Britain.

Tokyo, Sep 26 (IANS) Children with attention deficit hyperactivity disorder (ADHD) are potentially more exposed to reproaches, say researchers in a study that aimed to find the effect of punishment in children with the disorder.

Children with ADHD often get into trouble with their parents, teachers and friends, for their elevated activity levels, impulsive actions and difficulty in focusing. 

The findings showed that children with ADHD try to avoid punishment more often over time than other children without the disorder. 

On the other hand, for children without the disorder, punishment seemed to be less distractive as they keep their focus on winning.

"If a child with ADHD is reluctant in doing a task, or if the child gives up easily, it might be important for the parent or the teacher to check if the task has the appropriate balance of reward and punishment," said Gail Tripp, Professor at the Okinawa Institute of Science and Technology Graduate University (OIST), in Japan. 

"The task may not have punishment built in, rather the effort needed to do the task might be perceived as punishing by the child," Tripp added. 

For children without ADHD, the more effortful a task is, the more incentives a child is going to need to keep persisting.

"Simple but frequent rewards, such as smiles or words of encouragements, can help children with ADHD to stay on the task," Tripp suggested. 

The same could be said for children without the disorder, but this is especially important for children with ADHD, as they seem more sensitive to repeated experiences of punishment or failure, and are more likely to miss opportunities for success, the researchers said. 

For the study, a team of researchers involved 210 children from Japan and New Zealand. Out of these, 145 were diagnosed with ADHD. 

Both groups of children had to chose between playing two simultaneously available computer-based games that were engaging but still incorporated an element of punishment. 

In both games, when a child won, the computer gave him or her 10 points and played a simple animation. But when a child lost, the computer took away five points and played a laughing sound. 

Over time, the children with ADHD found losing points and the laughter more punishing than children without the disorder. They were also much less likely to play the more punishing game, the researchers concluded.

The results are published in the Journal of Child Psychology and Psychiatry.

​San Francisco, Sep 24 (IANS) Amid the rumours that the micro-blogging site Twitter may be up for sale to Google and Cloud computing company Salesforce, a top executive from Salesforce has tweeted why it makes sense to buy Twitter.