Knowledge Update

​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.

​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.

​Toronto, April 12 (IANS) Researchers have identified 26 new genes linked to intellectual disability which is characterised by significant limitations in learning.

More than one in 100 children worldwide is affected by intellectual disability. Frequently, intellectual disability also accompanies symptoms of autism spectrum disorders, and many genes have been found to be shared by the two illnesses.

The study, published online in the journal Molecular Psychiatry, could eventually lead to personalised treatments for affected individuals, and also add to our growing knowledge of brain development and functioning. 

"Knowing the genes involved is a big step forward, but understanding how they function is also crucial before we can start planning treatments or even cures," said team leader John Vincent from the Centre for Addiction and Mental Health in Toronto, Canada.

The study, which was jointly led with Muhammad Ayub of Queen's University in Canada, involved 192 families from Pakistan and Iran with more than one affected family member. 

Intellectual disability is frequently caused by recessive genes, meaning that an affected child gets a defective copy of the gene from each parent.

The families in the study all had a history of marriage among relatives, which occurs quite commonly in communities in South Asia, the Middle East and Africa. 

Studying families with this background, and multiple affected individuals, can enable researchers to identify disease genes that would otherwise remain hidden.

The research team pinpointed mutations related to intellectual disability in half of these 192 families. 

The identification of 26 new genes adds to 11 new genes that the team had previously linked to intellectual disability.

One immediate implication of the study is to prevent future cases of intellectual disability, the researchers note. 

Unaffected family members and relatives could be genetically screened to see if they carry these mutations. 

While 26 genes may seem a substantial number, there are likely hundreds of genes that, when defective, may lead to intellectual disability, the researchers pointed out. 

"The strategy we have used speeds up the process of identifying disease genes and of enabling diagnostic labs to deliver more accurate information for clinicians and families," Vincent said.

​London, April 12 (IANS) In a first, scientists have developed a drug activated by light which has therapeutic applications for the treatment of pain.

The new "photo-drug" -- JF-NP-26 -- is a molecule that can be specifically activated at any wished moment (that is, with a high spatiotemporal resolution) with light, the researchers said.

"This is the first light-activated drug designed for the treatment of pain in vivo with animal models," said Francisco Ciruela, Professor at the University of Barcelona. 

JF-NP-26 is activated when receiving light -- using an optical fibre -- of a suitable wave length and with an exact precision on the target tissue (brain, skin, articulations, etc).

The drug does not show toxic or unwanted effects even if the dose is high in short-length studies on animals.

The discovery, published in the journal eLife, will overcome the problems faced with the uses and effects of current drugs such as slow and inexact distribution of the drug, lack of spatiotemporal traits in the organism and difficulties in the dose adjustments, the researchers said.

JF-NP-26's lightening includes a treatment on the molecule that releases the active molecule (raseglurant) that blocks the metabotropic glutamate type 5 (mGlu5) receptor, found in lots of neuronal functions such as the spread of neuronal pain. 

Blocking this receptor allows preventing the pain from spreading into the brain. This can be produced both due to the outlying neurons and the central nervous system (brain) and create, in both cases, an analgesic effect as a result.

"The molecule created by the action of light, the raseglurant, does not belong to any group of drugs from the classic anti-pain list of drugs: non-steroidal anti-inflammatory drugs or NSAID (paracetamol, ibuprofen, etc.) and opioids (morphine, phentanyl)," Ciruela said.

​New York, April 12 (IANS) Ever wondered what causes your shoelaces to loosen even when you tie them as firmly as possible?

It is because while running, the force of a foot striking the ground stretches and then relaxes the knot, a study has showed. 

As the knot loosens, a second force caused by the swinging leg acts on the ends of the laces, like an invisible hand, which rapidly leads to a failure of the knot in as few as two strides after inertia acts on the laces.

The findings, published in the journal Proceedings of the Royal Society, may help understand things like DNA that fail under dynamic forces, the researchers said. 

"When you talk about knotted structures, if you can start to understand the shoelace, then you can apply it to other things, like DNA or microstructures, that fail under dynamic forces," said Christopher Daily-Diamond, graduate student at the University of California-Berkeley.

Using a slow-motion camera and a series of experiments, the researchers assessed a pair of running shoes that were laced-up and were on a treadmill. 

They found that shoelace knot failure happens in a matter of seconds, triggered by a complex interaction of forces, as when running, the foot strikes the ground at seven times the force of gravity.

In addition, the study showed that some laces might be better than others for tying knots, but the fundamental mechanics causing them to fail is the same.

"The interesting thing about this mechanism is that your laces can be fine for a really long time, and it's not until you get one little bit of motion to cause loosening that starts this avalanche effect leading to knot failure," said Christine Gregg, graduate student at the University of California-Berkeley.

​New York, April 12 (IANS) Individuals' different social etworking profile on sites like Facebook, Twitter, and LinkedIn stem from a desire to fit within the distinctive culture or etiquette of each site, say researchers, including one of Indian-origin.

The findings showed that users are not explicitly modifying their profile, but rather subconsciously adapting the behaviour modelled to fit in.

"Despite our best efforts, we do still fit stereotypes of gender and age in the way we tailor our persona," said Nishanth Sastry, Senior Lecturer at King's College London.

For instance, a photo of someone's colourful Starbucks drink may be popular on Instagram, but the same image post to LinkedIn would be frowned upon. 

"The users tend to portray themselves differently in these different worlds," added Dongwon Lee, Associate Professor at the Pennsylvania State University.

The findings will be presented at the International AAAI Conference on Web and Social Media (ICWSM) in Canada.

For the research, the team compiled information on over 100,000 social media users by utilising About.me -- a site that acts as a social media directory -- where users volunteer their own profiles, making it an extremely reliable dataset.

Upon analysing the profile pictures and biography information provided by these users, the team also found some surprising differences in how different demographics portray themselves. 

The results showed that women were less likely to wear corrective eyewear, like reading glasses, in their profile pictures and users under the age of 25 were less likely to be smiling in their profile picture.

"Social media consumes an increasingly large portion of our lives. Therefore, understanding how we interact with each other on social media is important to understanding who we are in the online world, and how we relate to each other in virtual but still meaningful ways," Sastry added. 

New York, April 11 (IANS) Astronomers have discovered a faint, incredibly distant galaxy, about 13.1 billion years in the past, just about 700 million years after the Big Bang.

The new object, named MACS1423-z7p64, was detailed in a study published in the journal Nature Astronomy.

The researchers used the Hubble space telescope to find the galaxy and confirmed its age and distance with instruments at the Keck Observatory in Hawaii.

"Other most distant objects are extremely bright and probably rare compared to other galaxies," said lead author Austin Hoag from University of California, Davis in the US. 

"We think this is much more representative of galaxies of the time," Hoag said.

These ultra-distant galaxies, seen as they were close to the beginning of the universe, are interesting because they fall within the "Epoch of Reionisation," a period about a billion years after the Big Bang when the universe became transparent.

After the Big Bang, the universe was a cloud of cold atomic hydrogen, which blocks light. 

The first stars and galaxies condensed out of the cloud and started to emit light and ionising radiation. 

This radiation melted away the atomic hydrogen like a hot sun clearing fog, and the first galaxies spread their light through the universe. But much remains lost in the fog of reionisation.

To find the faint faint, distant object, the astronomers took advantage of a giant lens in the sky.

As light passes by a massive object such as a galaxy cluster, its path gets bent by gravity, just as light gets bent passing through a lens. 

When the object is big enough, it can act as a lens that magnifies the image of objects behind it.

While it is similar to millions of other galaxies of its time, z7p64 just happened to fall into the "sweet spot" behind a giant galaxy cluster that magnified its brightness ten-fold and made it visible to the team, using the Hubble space telescope. 

They were then able to confirm its distance by analysing its spectrum with the Keck Observatory telescopes in Hawaii.

The team plans to continue their survey of candidate galaxies with the Hubble and Keck telescopes, and later with James Webb space telescope, set for launch in 2018.

It is expected that the Webb telescope, which is bigger than Hubble, will allow astronomers to look at even more distant parts of the universe, which will help astronomers answer the question of where did we come from.