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.​

Washington, May 5 (IANS) A team of US doctors has shown for the first time that soft tissue surgery can soon be performed entirely by a robot on humans, putting surgery one step closer into the realm of intelligent machines.

The so-called Smart Tissue Autonomous Robot (STAR) succeeded in suturing and reconnecting bowel segments in living pigs -- a procedure known as intestinal anastomosis -- and all the animals survived with no complications.

The STAR robotic sutures were compared with the work of five surgeons completing the same procedure using three methods -- open, laparoscopic and robot-assisted surgery with the well-known da Vinci Surgical System.

The robot's time was longer than open and robot-assisted surgery but comparable to the laparoscopic procedure. The robotic procedure lasted 35 to 57 minutes, while the open surgery took eight minutes.

Kuala Lumpur, May 5 (IANS) Social media giant Facebook has opened a local office in the Malaysian capital of Kuala Lumpur, a media report said on Thursday.

"The office launch marks a milestone for Facebook in Malaysia and we are committed to helping Malaysians and businesses connect in more meaningful ways," said Facebook

​London, May 4 (IANS) Taking at least 2-3 minutes rest between weight-lifting sets at the gym can help boost muscle growth, British researchers have found.

The results suggest that guys who took longer rest periods showed two-fold increase in myofibrillar protein synthesis (MPS) -- associated with strength and muscle growth.

The study highlights that short rest intervals may actually impair the processes that control muscle growth.

However, with short rests of one minute, the actual muscle response is blunted. 

“If you're looking for maximised muscle growth with your training programme, a slightly longer interval between sets may provide a better chance of having the muscle response you're looking for," said Leigh Breen from University of Birmingham in Britain.

The study, published in the journal Experimental Physiology, analysed 16 men who completed resistance exercises interspersed by either one minute or five minutes of rest. 

Muscle biopsies were obtained at 0, four, 24 and 28 hours post-exercise. 

Beginners starting out on weight training programmes should take sufficient rest, of at least 2-3 minutes, between weight lifting sets that can help with muscle growth, the authors recommended.

For experienced lifters, it's possible that they may not experience the same blunted muscle building response to short rest intervals particularly if they have trained this way for a prolonged period and adapted to this unique metabolic stress. 

"Nonetheless, similar recommendations of 2-3 minutes between sets should help ensure maximal muscle growth in well-trained individuals,” Breen added.​

​New York, May 5 (IANS) Consuming grapes combined with a diet rich in saturated fats can lower obesity risk as well as improve gut bacteria, a new study has found.

According to researchers, it may also help counter the negative effects of a high fat diet, including heart disease, hypertension and diabetes.

The findings showed that the unique and diverse composition of antioxidants called polyphenols present in grapes can help reduce the percentage of body fat, subcutaneous and visceral fat deposits, markers of inflammation in the liver and improve glucose tolerance.

Further, it also increased microbial diversity and decreased abundance of several deleterious bacteria in the intestinal tract.

The research, published in the Journal of Nutritional Biochemistry, is based on two laboratory studies.

In the first study, intake of a diet high in fat content (33 percent of energy from fat) and enriched with 3 percent grapes for 11 weeks, showed a lower percentage of overall body fat and reduced subcutaneous fat deposits.

In the second study, which ran for 16 weeks, the researchers used an even higher fat diet (44 percent of energy from fat) with multiple types of saturated fat, including lard, beef tallow, shortening, and butter similar to some Western-type diets.

"These two studies suggest that grapes and grape polyphenols may help offset a number of the adverse effects of consuming a high fat diet and trigger improvements in intestinal or systemic health," said lead researcher Michael McIntosh from the University of North Carolina in the US.

The researchers investigated the impact of the high fat diet enriched with extracts of either the polyphenol fraction of grapes or the non-polyphenol portion of grapes, as well as the high fat diet plus five percent whole grapes.

All the high fat experimental diets were matched for sugar type and amount.​

​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.​