Knowledge Update

​New York, April 15 (IANS) US scientists have created a revolutionary digital three dimensional (3D) bio-printed patch that can help heal scarred heart tissue in patients after a heart attack.

During a heart attack, a person loses blood flow to the heart muscle, causing the cells to die. 

As the human body cannot replace those heart muscle cells so it forms scar tissue in that area of the heart, which puts the person at risk of compromised heart function and future heart failure, the study said.

Using laser-based 3D bio-printing techniques, the researchers led by the University of Minnesota, incorporated stem cells derived from adult human heart cells on a matrix that began to grow and beat synchronously in a dish in the lab.

When the cell patch was placed on a mouse following a simulated heart attack, the researchers saw significant increase in functional capacity after just four weeks. 

Since the patch was made from cells and structural proteins native to the heart, it became part of the heart and absorbed into the body, requiring no further surgeries.

"Given the complexity of the heart, we were encouraged to see that the cells had aligned in the scaffold and showed a continuous wave of electrical signal that moved across the patch," said Brenda Ogle, Associate Professor at the University of Minnesota in the US. 

The patch, modelled after a digital, 3D scan of the structural proteins of native heart tissue, is made into a physical structure by 3D printing with proteins native to the heart and further integrating cardiac cell types derived from stem cells, the researchers said, in the paper published in the journal Circulation Research.

"We feel that we could scale this up to repair hearts of larger animals and possibly even humans within the next several years," Ogle noted. 

​Santiago, April 15 (IANS) Nearly 300 million years ago, the frozen, inhospitable Antarctica was covered by lush subtropical forests, according to scientists.

"That Antarctica was once green is a matter of consensus among scientists, but still unknown to many people," Marcelo Leppe, a paleontologist who works with the Chilean Antarctic National Institute, told Efe news on Friday.

Leppe, Chile's representative to the international Scientific Committee on Antarctic Research, has spent his professional life searching for fossils that offer clues to the origins of the flora and fauna of the White Continent.

Forests began to appear in Antarctica some 298 million years ago during the Permian geologic period, as glaciers retreated and the global climate entered a warming phase, Leppe said.

Fossils from the subsequent Jurassic period reveal the existence of fern and conifer forests where the Cryolophosaurus species of dinosaur thrived.

But the golden age of vegetation in Antarctica was the Cretaceous period, which began 145 million years ago and lasted until around 66 million years ago.

"Roughly 80 million years ago, walking in Antarctica was like walking today in a tropical or subtropical forest, something like what we could encounter in south-central Chile or in New Zealand," Leppe said.

One thing that still puzzles scientists is how the forests survived the six-month-long Antarctic night.

"We know that some dinosaurs migrated before the arrival of winter, but in the case of plants, the matter continues to be an enigma," the paleontologist said.

While the plants would have received as much as 22 hours of light per day during the Antarctic summer, "that doesn't necessarily imply that they had the capacity to carry out photosynthesis for longer hours than now," he said.

The tundra that was the last vestige of the forests disappeared 15 million years ago, leaving Antarctica a frozen desert.

Now, however, scientists see grass and wild oats growing in the areas of Antarctica where the ice has retreated due to global warming, Leppe said.

Climate change, the introduction of invasive plants, and the retreat of the glaciers are creating the conditions for the White Continent to turn green again.

​San Francisco, April 14 (IANS) Aiming to secure a stable supply of memory chips for its iPhones, US tech giant Apple may invest billions of dollars to obtain a substantial stake in struggling Japanese conglomerate Toshiba's chip business, media reported on Friday.

New York, April 14 (IANS) Facebook's photo-sharing app Instagram has surpassed Snapchat in daily active users of "Stories" feature, though the format was first launched by Snapchat in 2013. According to a report in Forbes on Thursday, Instagram's "Stories" feature is now used by more than 200 million people every day -- an increase of 50 million since January. On the other hand, Snapchat who launched the "Stories" format in October 2013, had 161 million daily active users in February. "Stories" feature is an ephemeral chain of photo and video clips with filters and special effects. More recently, Facebook and WhatsApp also introduced the feature, imitating Snapchat. "Instagram Stories appears to have directly hampered Snapchat's user growth since its debut. Snapchat attributed its slowing pace in part to issues with Android updates and increasing competition. However, Instagram's impact on the chat app seems undeniable," the report noted. On May 10, the focus will be on Snapchat's user growth when Snap reports first quarter earnings.

​New York, April 14 (IANS) Google's digital wallet Android Pay is joining several banks around the world including Bank of America, Bank of New Zealand, Discover, mBank and USAA, to make it even easier for its users to pay with Android Pay.

​Shanghai, April 14 (IANS) The Brics New Development Bank (NDB) has planned to issue bonds twice this year, one denominated in Chinese yuan and the other in Indian rupee, bank's President K.V. Kamath said on Friday.

​New York, April 14 (IANS) Researchers have developed a diagnostic platform based on the gene editing tool CRISPR which could one day be used to respond to viral and bacterial outbreaks, monitor antibiotic resistance, and detect cancer.

The researchers adapted a CRISPR protein that targets RNA as a rapid, inexpensive, highly sensitive diagnostic tool.

The new tool, dubbed SHERLOCK (Specific High-sensitivity Enzymatic Reporter unLOCKing), can be designed for use as a paper-based test that does not require refrigeration.

It is well suited for fast deployment and widespread use inside and outside of traditional settings -- such as at a field hospital during an outbreak, or a rural clinic with limited access to advanced equipment, the researchers said.

"There is great excitement around this system," said study co-author Deborah Hung from Broad Institute of MIT and Harvard in in Cambridge, Massachusetts, US.

"There is still much work to be done, but if SHERLOCK can be developed to its full potential it could fundamentally change the diagnosis of common and emerging infectious diseases," Hung said.

In a study published in the journal Science, the researchers described how this RNA-targetting CRISPR enzyme, Cas13a, was harnessed as a highly sensitive detector -- able to indicate the presence of as little as a single molecule of a target RNA or DNA molecule. 

The scientists demonstrated the method's versatility on a range of applications, including detecting the presence of Zika virus in patient blood or urine samples within hours, and rapidly reading human genetic information, such as risk of heart disease, from a saliva sample.

"We can now effectively and readily make sensors for any nucleic acid, which is incredibly powerful when you think of diagnostics and research applications," said Jim Collins, Professor of Bioengineering at MIT, and faculty member at the Wyss Institute for Biologically Inspired Engineering at Harvard. 

"This tool offers the sensitivity that could detect an extremely small amount of cancer DNA in a patient's blood sample, for example, which would help researchers understand how cancer mutates over time," Collins said.

​New York, April 14 (IANS) Exposure to higher levels of air pollution may increase cardiovascular disease risk by lowering levels of high-density lipoprotein (HDL), commonly known as "good" cholesterol, says a study.

Higher exposure to black carbon, a marker of traffic-related pollution, is significantly associated with a lower "good" cholesterol level, showed the findings published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology.

The lower levels of HDL observed with high levels of air pollution "may put individuals at a higher risk for cardiovascular disease down the line," said lead author Griffith Bell from the University of Washington School of Public Health in Seattle.

In the study of 6,654 middle-aged and older US adults from diverse ethnic backgrounds, participants living in areas with high levels of traffic-related air pollution tended to have lower HDL levels.

Higher particulate matter exposure over three months was associated with a lower HDL particle number, the researchers said. 

Changes in HDL levels may already appear after brief and medium-length exposures to air pollution, the authors noted.

Men and women responded to air pollutants differently. While HDL was lower at higher pollution exposure for both sexes, but the magnitude was greater in women.

The findings are part of the Multi-Ethnic Study of Atherosclerosis, an ongoing US study examining the lifestyle factors that predict development of cardiovascular disease. 

​Washington, April 14 (IANS) Saturn's icy moon Enceladus has a form of chemical energy that life can feed on, researchers with NASAs Cassini mission to Saturn have revealed.

"Confirmation that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone in our search for habitable worlds beyond Earth," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

In a separate study, scientists also reported additional evidence of water vapour plumes erupting from Jupiter's moon Europa.

Together, the findings suggest that these active ocean worlds in our solar system are worth more exploration in our search for life beyond the Earth. 

The study from researchers with the Cassini mission, published in the journal Science, indicates hydrogen gas -- which could potentially provide a chemical energy source for life -- is pouring into the subsurface ocean of Enceladus from hydrothermal activity on the seafloor.



The presence of ample hydrogen in the moon's ocean means that microbes -- if any exist there -- could use it to obtain energy by combining the hydrogen with carbon dioxide dissolved in the water. 



This chemical reaction, known as "methanogenesis" because it produces methane as a byproduct, is at the root of the tree of life on the Earth, and could even have been critical to the origin of life on our planet.



Life as we know it requires three primary ingredients: liquid water; a source of energy for metabolism; and the right chemical ingredients, primarily carbon, hydrogen, nitrogen, oxygen, phosphorous and sulphur. 



With this finding, Cassini has shown that Enceladus -- a small, icy moon a billion miles farther from the Sun than the Earth -- has nearly all of these ingredients for habitability. 



Cassini has not yet shown phosphorous and sulphur are present in the ocean, but scientists suspect them to be, since the rocky core of Enceladus is thought to be chemically similar to meteorites that contain the two elements.



The Cassini spacecraft detected the hydrogen in the plume of gas and icy material spraying from Enceladus during its last, and deepest, dive through the plume on October 28, 2015. 



Cassini also sampled the plume's composition during flybys earlier in the mission. 



From these observations scientists have determined that nearly 98 per cent of the gas in the plume is water, about one per cent is hydrogen and the rest is a mixture of other molecules including carbon dioxide, methane and ammonia.

At the same time, NASA scientists have also reported additional evidence of water vapour plumes erupting from Jupiter's moon Europa.

The paper detailing new Hubble space telescope findings, published in The Astrophysical Journal Letters, reports on observations of Europa from 2016 in which a probable plume of material was seen erupting from the moon's surface at the same location where Hubble saw evidence of a plume in 2014. 

These images bolster evidence that the Europa plumes could be a real phenomenon, flaring up intermittently in the same region on the moon's surface.

Researchers speculate that, like Enceladus, this could be evidence of water erupting from the moon's interior.

NASA's will send a probe called Europa Clipper mission, which is planned for launch in the 2020s, to search signs of life on the Jupiter's moon by flying through those plumes.

"If there are plumes on Europa, as we now strongly suspect, with the Europa Clipper we will be ready for them," said Jim Green, Director of Planetary Science, at NASA Headquarters.

​New York, April 14 (IANS) Artificial intelligence-powered machines can be reflections of humans and can acquire cultural biases, a new study has found.

Researchers from Princeton University and University of Bath have found that common machine learning programmes, when trained with ordinary human language available online, can acquire cultural biases embedded in the patterns of wording.

These biases range from the morally neutral to the objectionable views -- preference for birds over animals to views on race and gender.

"We have a situation where these artificial intelligence systems may be perpetuating historical patterns of bias that we might find socially unacceptable and which we might be trying to move away from," said Arvind Narayanan, Assistant Professor at Princeton University.

Researchers believe that it is important to identify and address these biases in machines as humans increasingly turn to computers for processing the natural language humans use to communicate.

In their findings, the researchers found that the machine learning programme associated female names more with familial words, like "parents" and "wedding" than male names, while it associated male names with career attributes, like "professional" and "salary". 

"Of course, results such as these are often just objective reflections of the true, unequal distributions of occupation types with respect to gender -- like how 77 per cent of computer programmers are male," the study published in the journal Science noted.

The findings point out that machine learning methods are not 'objective' or 'unbiased' just because they rely on mathematics and algorithms.

"Rather, as long as they are trained using data from society and as long as society exhibits biases, these methods will likely reproduce these biases," said Hanna Wallach, a researcher at Microsoft Research New York City.