Knowledge Update

Washington, April 18 (IANS) An increased risk of autism among children of women who took antidepressants during pregnancy may actually be the result of maternal mental illnesses, according to new research.

Up to 15 per cent of women have depression during pregnancy and antidepressants are a popular treatment choice for those with depression, Xinhua news agency reported.

However, there has been a long-standing debate about whether expectant mothers with depression should take antidepressants.

In a paper published by the US journal JAMA Pediatrics, Antonia Mezzacappa of the Bicetre University in France and colleagues reviewed and analysed 10 studies that have explored associations between fetal exposure to antidepressants and autism spectrum disorders (ASDs).

"Based on our meta-analyses, there is a significant association between ASDs and prenatal maternal use of antidepressants. However, it appears to be more consistent during pre-pregnancy than each trimester," the study noted.

The study also found that the association was weaker when past maternal illness of the mother was controlled for.

As a result, the study said the public health implications of the possible risk for ASDs as a result of antidepressant exposure during pregnancy are "difficult to assert or to refute, especially as we also observed an association with preconception exposure."

"The increased risk for ASDs in children exposed in utero could well be related to maternal depression or other psychiatric disorders rather than to antidepressant medications per se," it concluded. 

Irene Petersen, a researcher at the University College London, who was not involved in the study, said it's tricky to study the exposure on antidepressants in pregnancy and the risk of ASDs, as the effects of drug treatment are often difficult to be separated from other risk factors such as maternal illnesses.

"The findings from this review suggest that antidepressant treatment may be a 'marker' of women who may have an elevated risk of giving birth to a child with ASD," Petersen said.

"However, I would be very cautious about reaching a conclusion that antidepressants treatment in pregnancy itself is causing autism. With the existing evidence, we still cannot exclude the possibility that it is maternal illnesses linked to ASD -- and not the antidepressants," he added.

New York, April 18 (IANS) Anti-inflammatory properties in a cannabis compound could help treat itching and a wide-range of other skin diseases, say researchers.

The new study, published online in the Journal of the American Academy of Dermatology, summarises the current literature on the subject and concludes that pharmaceuticals containing cannabinoids may be effective against eczema, psoriasis, atopic and contact dermatitis.

"Perhaps the most promising role for cannabinoids is in the treatment of itch," said the study's senior author Robert Dellavalle, Associate Professor of Dermatology at the University of Colorado School of Medicine in the US.

In one study, eight of 21 patients who applied a cannabinoid cream twice a day for three weeks completely eliminated severe itching or pruritus. The drug may have reduced the dry skin that gave rise to the itch, Dellavalle said.

The primary driver in these cannabinoid treatments could be their anti-inflammatory properties, he added.

In the studies reviewed, the researchers found that THC (tetrahydrocannabinol) the active ingredient in marijuana, reduced swelling and inflammation in mice.

At the same time, mice with melanoma saw significant inhibition of tumour growth when injected with THC.

"These are topical cannabinoid drugs with little or no psychotropic effect that can be used for skin disease," Dellavalle said.

Still, Dellavalle cautioned that most of these studies are based on laboratory models and large-scale clinical trials have not been performed.

​New York, April 17 (IANS) Google is reportedly building an overhauled version of its Google Earth that will be unveiled during an Earth Day event in New York City on April 18, a media report said.

According to a report in Express.co.uk on Monday, Google has sent invitations for an Earth Day-themed event to be held at Whitney Museum of Art in New York City.

Google Earth is a virtual globe that allows users to trawl satellite images of the planet's surface. It uses image resolutions that range between 15m to 15cm. One can search any area on the earth through Google Earth. 

It is assumed that the new version of Google Earth would replace its Google Maps app.

In 2008, Google included its Street View feature that offers a panoramic view from eye-level of streets across the world, in Google Maps.

A dramatically revamped version of Google Earth could bring in more functionality from Google Maps, including traffic reports and local listings, the report said.

​London, April 16 (IANS) Turning 25? This may be the best time of your life, as according to a study, 25 is the golden age when humans can outsmart computers.

The study showed that people's ability to make random choices or mimic a random process, such as coming up with hypothetical results for a series of coin flips, peaks around age 25.

At their peak, humans outcompete many computer algorithms in generating seemingly random patterns, an ability that arises from some of the most highly developed cognitive processes in humans and may be connected to abilities such as human creativity, the researchers said, in the paper published in the journal PLOS Computational Biology.

"This experiment is a kind of reverse Turing test for random behaviour, a test of strength between algorithms and humans," said Hector Zenil from the Algorithmic Nature Group in France.

"25 is, on average, the golden age when humans best outsmart computers," added Nicolas Gauvrit from the Algorithmic Nature Group.

Previous studies have shown that ageing diminishes a person's ability to behave randomly. However, it had been unclear how this ability evolves over a person's lifetime, nor had it been possible to assess the ways in which humans may behave randomly beyond simple statistical tests.

For the study, the team assessed more than 3,400 people aged four to 91 years old, who were asked to perform a series of online tasks that assessed their ability to behave randomly.

The scientists analysed the participants' choices according to their algorithmic randomness, which is based on the idea that patterns that are more random are harder to summarise mathematically.

After controlling for characteristics such as gender, language, and education, they found that age was the only factor that affected the ability to behave randomly. This ability peaked at age 25, on average, and declined from then on, the researchers noted.

​New York, April 16 (IANS) A team led by an Indian-origin engineer has built a camera prototype that can capture a detailed micron-resolution image from a distance and does that without using a long lens.

The prototype built and tested by engineers at US-based Rice and Northwestern universities uses a laser and techniques borrowed from holography, microscopy and "Matrix"-style bullet time.

It reads a spot illuminated by a laser and captures the "speckle" pattern with a camera sensor. 

Raw data from dozens of camera positions is fed to a computer programme that interprets it and constructs a high-resolution image.

The system known as SAVI -- "Synthetic Apertures for long-range, subdiffraction-limited Visible Imaging" -- only works with coherent illumination sources such as lasers.

"Today, the technology can be applied only to coherent (laser) light," said Ashok Veeraraghavan, a Rice University Assistant Professor of electrical and computer engineering, in a statement.

"That means you cannot apply these techniques to take pictures outdoors and improve resolution for sunlit images -- as yet. Our hope is that one day, maybe a decade from now, we will have that ability," he added.

The technology is the subject of an open-access paper in Science Advances.

Labs led by Veeraraghavan tested the device that compares interference patterns between multiple speckled images.

Veeraraghavan explained the speckles serve as reference beams and essentially replace one of the two beams used to create holograms. 

When a laser illuminates a rough surface, the viewer sees grain-like speckles in the dot. That's because some of the returning light scattered from points on the surface has farther to go and throws the collective wave out of phase. 

SAVI's "synthetic aperture" sidesteps the problem by replacing a long lens with a computer programme that resolves the speckle data into an image. 

"You can capture interference patterns from a fair distance. How far depends on how strong the laser is and how far away you can illuminate," Veeraraghavan added.

​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.

​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.