Knowledge Update

New York, May 6 (IANS) Your favourite strawberries and bananas can stay fresh for more than a week without refrigeration if they are coated in a thin, odourless, biocompatible silk solution, says a study.

Silk's unique crystalline structure makes it one of nature's toughest materials. Fibroin, an insoluble protein found in silk, has a remarkable ability to stabilise and protect other materials while being fully biocompatible and biodegradable.

For the study, the researchers dipped freshly picked strawberries in a solution of one percent silk fibroin protein. The coating process was repeated up to four times. 

The silk fibroin-coated fruits were then treated for varying amounts of time with water vapour under vacuum (water annealed) to create varying percentages of crystalline beta-sheets in the coating. 

The strawberries were then stored at room temperature. Uncoated berries were compared over time with berries dipped in varying numbers of coats of silk that had been annealed for different periods of time. 

At seven days, the berries coated with the higher beta-sheet silk were still juicy and firm while the uncoated berries were dehydrated and discoloured.

Tests showed that the silk coating prolonged the freshness of the fruits by slowing fruit respiration, extending fruit firmness and preventing decay.

"The beta-sheet content of the edible silk fibroin coatings made the strawberries less permeable to carbon dioxide and oxygen. We saw a statistically significant delay in the decay of the fruit," said senior study author Fiorenzo Omenetto, professor at Tufts University in Massachusetts, US.

Similar experiments were performed on bananas, which, unlike strawberries, are able to ripen after they are harvested. 

The silk coating decreased the bananas' ripening rate compared with uncoated controls and added firmness to the fruit by preventing softening of the peel.

The findings were published in the journal Scientific Reports.

Half of the world's fruit and vegetable crops are lost during the food supply chain, due mostly to premature deterioration of these perishable foods, according to the Food and Agriculture Organisation (FAO) of the United Nations.​

London, May 6 (IANS) Banking on new research and modern detective technologies including DNA science, a team of specialists has come together to create new insights into the life of Italian genius Leonardo da Vinci.

The “Leonardo Project” is in pursuit of several possible physical connections to Leonardo - beaming radar, for example, at an ancient Italian church floor to help corroborate extensive research to pinpoint the likely location of the tomb of his father and other relatives. 

A collaborating scholar also recently announced the successful tracing of several likely DNA relatives of Leonardo living today in Italy.

If granted the necessary approvals, the “Leonardo Project” will compare DNA from Leonardo's relatives past and present with physical remnants -- hair, bones, fingerprints and skin cells -- associated with the Renaissance figure whose life marked the rebirth of western civilisation.

“Everyone in the group believes that Leonardo, who devoted himself to advancing art and science, who delighted in puzzles and whose diverse talents and insights continue to enrich society five centuries after his passing, would welcome the initiative of this team -- indeed would likely wish to lead it were he alive today,” explained Jesse Ausubel, vice chairman of the Richard Lounsbery Foundation and sponsor of the project's meetings.

Born in Vinci, Italy, da Vinci died in 1519 at age 67 and was buried in Amboise, southwest of Paris. 

His creative imagination foresaw and described innovations hundreds of years before their invention, such as the helicopter and armoured tank. His artistic legacy includes the iconic “Mona Lisa” and “The Last Supper”.

If DNA and other analyses yield a definitive identification, conventional and computerised techniques might reconstruct the face of da Vinci from models of the skull.

In addition to Leonardo's physical appearance, information potentially revealed from the work includes his ancestry and additional insight into his diet, state of health, personal habits and places of residence.

It may also make a lasting contribution to the art world, within which forgery is a multi-billion dollar industry, by advancing a technique for extracting and sequencing DNA from other centuries-old works of art, and associated methods of attribution.

One objective is to verify whether fingerprints on Leonardo's paintings, drawings and notebooks can yield DNA consistent with that extracted from identified remains.

If human DNA can one day be obtained from da Vinci's work and sequenced, the genetic material could then be compared with genetic information from skeletal or other remains that may be exhumed in the future.

“The fact that a team of eminent scholars from different academic disciplines and parts of the world has united with the common objective of furthering investigation into one of the greatest geniuses is positive and very important,” added Eugenio Giani, president of the Regional Council of Tuscany.

The idea behind the project has united anthropologists, art historians, genealogists, microbiologists, and other experts from leading universities and institutes in France, Italy, Spain, Canada and the US, including specialists from the J. Craig Venter Institute of California which pioneered the sequencing of the human genome.

The project's objectives, motives, methods and work to date are detailed in a special issue of the journal Human Evolution​

New York, May 6 (IANS) A team of astronomers has for the first time derived a highly precise measurement of the mass of a black hole -- calculating its mass to be 660 million times greater than that of the Sun.

Working with high-resolution data from the Atacama Large Millimetre/submillimetre Array in Chile, the scientists determined the speed of a disk of cold molecular gas and dust orbiting the supermassive black hole at the heart of a nearby giant elliptical galaxy named "NGC 1332".

"This is the first time that ALMA has probed the orbital motion of cold molecular gas well inside the gravitational sphere of influence of a supermassive black hole," said Aaron Barth, professor of physics and astronomy from the University of California-Irvine.

"We're directly viewing the region where the cold gas is responding to the black hole's gravitational pull. This is an exciting milestone for ALMA and a great demonstration of its high-resolution capability," added Barth in a paper appeared in the Astrophysical Journal Letters. 

To calculate the mass of a black hole in a galaxy's centre, astronomers must be able to measure the speed of something orbiting around it.

Barth and his group trained ALMA's observational powers on NGC 1332, a giant elliptical galaxy in the southern sky 73 million light-years from the Earth.

Elliptical galaxies are known to contain massive central black holes.

About one in 10 elliptical galaxies contain disks of cold molecular gas and dust that orbit their centres. 

In visible light, as seen by the Hubble Space Telescope, these disks appear as dark silhouettes against the bright background of starlight in a galaxy's core. 

But ALMA can observe radio-wavelength light emitted by molecules in these structures. 

In this case, Barth's team focused on radio-wave emissions from carbon monoxide (CO) molecules as the CO signal is bright and readily detected with ALMA.

By mapping the disk's rotation with the high-resolution data, Barth's group determined that the black hole in NGC 1332 has a mass that is 660 million times greater than the Sun -- with a measurement uncertainty of just 10 percent. 

This is among the most precise measurements for the mass of a galaxy's central black hole.

"This observation demonstrates a technique that can be applied to many other galaxies to measure the masses of supermassive black holes to remarkable precision," added study co-author Benjamin Boizelle.

The findings can help shed light on how galaxies and their supermassive black holes.

The team included astronomers from the University of California, Irvine, University of Colorado, Rutgers University, the Kavli Institute for Astronomy and Astrophysics at Peking University in Beijing, China, and Texas A&M University.​

London, May 5 (IANS) Long-eared bats are assisted in flight by their ears and body, say scientists, adding that this knowledge into the bats' flying technique can help develop better drones.

Contrary to what researchers previously assumed, Christoffer Johansson Westheim and his colleagues from Lund University in Sweden show that long-eared bats are helped in flight by their large ears.

They show how the air behind the body of a long-eared bat accelerates downwards, which means that the body and ears provide lift.

“This distinguishes the long-eared bats from other species that have been studied and indicates that the large ears do not merely create strong resistance, but also assist the animal in staying aloft", said Westheim.

The findings also highlight the evolutionary conflict between flying as efficiently as possible and eco-locating - discovering objects by sending out soundwaves and perceiving the resulting echoes.

Another discovery made during the experiments and never previously described in research is how the bats generate forward motion when flying slowly.

The forward motion is generated when the wings are held high and away from the body at the end of each beat.

"This specific way of generating power could lead to new aerodynamic control mechanisms for drones in the future, inspired by flying animals", Westheim added in a university statement.

The experiments were conducted in a wind tunnel in which trained bats flew through thin smoke to reach a stick with food on it.

Meanwhile the researchers aimed a laser beam at the smoke behind the bats and took pictures of the illuminated smoke particles.

The researchers then measured how the smoke moved to calculate the forces generated by each beat of the bats' wings.​

London, May 5 (IANS) Viral respiratory tract infections -- like the common cold, flu, tonsillitis, bronchitis and pneumonia -- during the first six months of life are likely to increase the risk for Type-1 diabetes in children, says a new study.

The findings suggest that the first half-year of life is crucial for the development of the immune system and of autoimmune diseases such as Type-1 diabetes (T1D).

According to researchers, T1D risk increased in children who had a respiratory tract infection between birth and 2.9 months or between three and 5.9 months of age compared with children who had no respiratory tract infections in these age intervals.

"Our findings show that viral respiratory tract disorders during the first six months of life significantly increase the risk of children developing Type-1 diabetes," said one of the researchers, Andreas Beyerlein, from Helmholtz Zentrum Munchen in Germany.

Infants are particularly susceptible to respiratory tract infections like the common cold, flu, tonsillitis, bronchitis and pneumonia, because, unlike adults, their immune systems have not acquired the immunity to stave off some of the viruses that cause them.

The study included 295,420 infants, of whom 720 were diagnosed with T1D over a median follow-up of 8.5 years, for an incidence of 29 diagnoses per 100,000 children annually. 

At least one infection was reported during the first two years of life in 93 percent of all children, and in 97 percent of children with T1D.

Most children experienced respiratory and viral infections. 

T1D risk was also found increased among children who experienced a viral infection between birth and 5.9 months of age.

The study was published in the journal JAMA.​

​London, May 5 (IANS) Studying a nearby star has given scientists a fascinating insight into how the Sun may have behaved billions of years ago.

A team of international astronomers, including professor Stefan Kraus of the University of Exeter in Britain, used cutting-edge techniques to create the first direct image of surface structures on the star Zeta Andromedae - found 181 light years from Earth.

In order to image the star's surface during one of its 18-day rotations, the researchers used a method called interferometry where the light of physically separate telescopes is combined in order to create the resolving power of a 330m telescope.

Found in the northern constellation of Andromeda, the star showed signs of “starspots” - the equivalent of sunspots found within our own solar system. The pattern of these spots differs significantly from those found on the Sun.

The researchers suggest these results challenge current understandings of how magnetic fields of stars influence their evolution.

Furthermore, they believe that the findings offer a rare glimpse of how the Sun behaved in its infancy, while the solar system was first forming.

“Most stars behave like giant rotating magnets and 'starspots' are the visible manifestation of this magnetic activity. Imaging these structures can help us to decipher the workings that take place deep below the stellar surface,” said Kraus.

“While imaging sunspots was one of the first things that astronomer Galileo Galilei did when he started using the newly-invented telescope, it has taken more than 400 years for us to make a powerful enough telescope that can image spots on stars beyond the Sun," added John Monnier, professor of astronomy in University of Michigan.

It's important to understand the Sun's history because that dictates the Earth's history -- its formation and the development of life.

“The better we can constrain the conditions of the solar environment when life formed, the better we can understand the requirements necessary for the formation of life,” said Rachael Roettenbacher, who conducted this research as part of her doctoral thesis at University of Michigan.

The findings were published in the scientific journal Nature.​

​Washington, May 5 (IANS) Pluto behaves less like a comet than expected and somewhat more like a planet like Mars or Venus in the way it interacts with the solar wind -- a continuous stream of charged particles from the Sun, a first ever analysis has revealed.

Using data from the New Horizons flyby of Pluto last year, scientists have observed the material coming off of Pluto's atmosphere and studied how it interacts with the solar wind, leading to yet another "Pluto surprise".

"This is a type of interaction we've never seen before anywhere in our solar system," said David J. McComas, professor of astrophysical sciences at the Princeton University.

According to space physicists, they now have a treasure trove of information about how Pluto's atmosphere interacts with the solar wind.

Solar wind is the plasma that spews from the Sun into the solar system at a supersonic 160 million km per hour, bathing planets, asteroids, comets and interplanetary space in a soup of mostly protons and electrons.

Previously, most researchers thought that Pluto was characterised more like a comet which has a large region of gentle slowing of the solar wind as opposed to the abrupt diversion solar wind encounters at a planet like Mars or Venus.

Instead, like a car that is part gas-and part battery-powered, Pluto is a hybrid, researchers said.

"These results speak to the power of exploration. Once again we've gone to a new kind of place and found ourselves discovering entirely new kinds of expressions in nature," added Alan Stern, New Horizons' principal investigator.

Since it is so far from the Sun, scientists thought Pluto's gravity would not be strong enough to hold heavy ions in its extended atmosphere.

But, "Pluto's gravity clearly is enough to keep material relatively confined", McComas noted.

Like the Earth, Pluto has a long ion tail that extends downwind at least a distance of about 118,700 km, almost three times the circumference of the Earth, loaded with heavy ions from the atmosphere and with "considerable structure".

The findings, published in the Journal of Geophysical Research-Space Physics offer clues to the magnetised plasmas that one may find around other stars.​

​London, May 5 (IANS) Large meteorite and comet impacts in the sea created structures that provided conditions favourable for life on Earth, reveal geochemists from Trinity College Dublin in Ireland.

Water then interacted with impact-heated rock to enable synthesis of complex organic molecules and the enclosed crater itself was a microhabitat within which life could flourish, said the team.

It has long been suggested that the meteoritic and cometary material that bombarded early Earth delivered the raw materials - complex organic molecules and water - and the energy that was required for synthesis. 

According to the researchers, impact craters were ideal environments to facilitate the reactions that saw the first “seeds of life” take root.

“The findings suggest that extensive hydrothermal systems operated in an enclosed impact crater at Sudbury, Ontario, Canada,” said first study author Edel O'Sullivan in a paper published in the journal Geochimica et Cosmochimica Acta.

The Sudbury basin provides a unique opportunity to study the sediment that filled the basin as a guide to what the earlier impact craters would have looked like. 

The Sudbury structure has an unusually thick basin fill and much of this is almost black in colour (due to carbon), also containing hydrothermal metal deposits.

To reach these findings, representative samples across the basin fill were analysed for their chemistry and for carbon isotopes.​

​New York, May 5 (IANS) Researchers have discovered how an immune system molecule hijacks a brain circuit and reduces appetite when you are inflicted with an illness.

While loss of appetite during illness is common, it contributes to reducing a patient's strength and in cancer patients, it can even shorten lifespan.

The new research points to potential targets for treating loss of appetite and restoring a patient's strength.

"Treating loss of appetite won't cure an underlying disease, but it could help a patient cope," said senior author of the study Bruno Conti, professor at The Scripps Research Institute (TSRI) in California, US.

"Many times, loss of appetite can compromise clinical outcome. A weak individual is less likely to be able to cope with chemotherapy, for instance," Conti said.

Many people recover their appetite after illness. But in patients with diseases such as cancer or AIDS, loss of appetite can turn into a wasting disease called cachexia, also known as "the last illness" because it can accelerate a patient's decline.

The findings were published in The Journal of Neuroscience.

The researchers believe the circuit affected by an immune molecule called interleukin 18 (IL-18) may be a potential drug target for treating loss of appetite, and possibly support weight loss for those with metabolic disorders.

"IL-18 regulates feeding by locking directly into the neuronal circuitry," Conti said.​

New York, May 4 (IANS) Medical error is the third leading cause of death in the US after heart disease and cancer, experts have said.

While accurate data on deaths associated with medical error is lacking, recent estimates suggest a range of 210,000 to 400,000 deaths a year among hospital patients in the US.

Using studies from 1999 onwards - and extrapolating to the total number of US hospital admissions in 2013 - the researchers calculated a mean rate of death from medical error of 251,454 a year.

Comparing their estimate to the annual list of the most common causes of death in the US, compiled by the Centers for Disease Control and Prevention (CDC), suggests that medical error is the third most common cause of death in the US.

"Although we cannot eliminate human error, we can better measure the problem to design safer systems mitigating its frequency, visibility, and consequences," the researchers said in the article published in the journal The BMJ.

Death certificates in the US have no facility for acknowledging medical error, lamented the researchers Martin Makary and Michael Daniel from Johns Hopkins University School of Medicine in Baltimore.

Currently, death certification in the US relies on assigning an International Classification of Disease (ICD) code to the cause of death - so causes of death not associated with an ICD code, such as human and system factors, are not captured.

The researchers suggested three strategies to reduce death from medical care - making errors more visible when they occur so their effects can be intercepted, having remedies at hand to rescue patients, and making errors less frequent by following principles that take human limitations into account.

For instance, instead of simply requiring cause of death, they suggest that death certificates could contain an extra field asking whether a preventable complication stemming from the patient's medical care contributed to the death.

Another strategy would be for hospitals to carry out a rapid and efficient independent investigation into deaths to determine the potential contribution of error.

Measuring the consequences of medical care on patient outcomes "is an important prerequisite to creating a culture of learning from our mistakes, thereby advancing the science of safety and moving us closer towards creating learning health systems," the researchers noted.​