Knowledge Update

​Washington, April 19 (IANS) NASA's Mars Reconnaissance Orbiter (MRO) has captured a region of Mars sprayed with mysterious secondary craters.

"Secondary craters form from rocks ejected at high speed from the primary crater, which then impact the ground at sufficiently high speed to make huge numbers of much smaller craters over a large region," NASA said in a statement on Tuesday.

"In this scene, however, the secondary crater ejecta has an unusual raised-relief appearance like bas-relief sculpture," NASA added.

So how did that happen?

One idea is that the region was covered with a layer of fine-grained materials like dust or pyroclastics about one to two metres thick when the Zunil impact occurred (about a million years ago), and the ejecta served to harden or otherwise protect the fine-grained layer from later erosion by the wind, NASA scientists said.

​Hyderabad, April 13 (IANS) The Nuclear Fuel Complex (NFC), part of the Department of Atomic Energy (DAE), on Thursday said it has set a new world record with production of 1512 Ametric tonnes (MT) of nuclear fuel in 2016-17, surpassing its own record

NFC in Hyderabad, which produces fuel assemblies required for all the operating nuclear power reactors in the country, became world's highest producer of nuclear fuel with the production of 1503 MT of pressurised heavy-water reactor (PHWR) fuel bundles during 2015-16.

NFC is the only organisation in the world today having a comprehensive nuclear fuel manufacturing cycle - from ore to core, involving processing of both Uranium and Zirconium streams all under a single roof, it said in a statement.

The organisation made a modest beginning with 100 MT per year Aand went on augmenting it's capacity to cater to the fuel requirement of all the operating Pressurised Heavy Water Reactors (PHWRs) and Boiling Water Reactors (BWRs).

NFC attributed the increased production to process improvement and automation, besides the dedicated efforts by its employees.

It also achieved the highest production of 1154 MT of Zirconium Oxide powder and 759 MT of Zirconium Sponge from its production units at Hyderabad and at Zirconium Complex (ZC), Pazhayakayal to meet the Zircaloy requirements of the PHWRs and BWRs.

The Complex is also engaged in the manufacturing of various Zirconium alloy reactor core structurals for PHWRs and BWRs, apart from manufacture of all the sub-assemblies and special requirement of Prototype Fast Breeder Reactor (PFBR) being set up at Kalpakkam, Tamil Nadu.

NFC over the years has mastered the technology of manufacturing seamless tubes and has been meeting critical requirements of the departments of atomic energy, space and defence, be it for the Light Combat Aircraft (LCA), battle tanks, missiles, supercritical boilers or the BrahMos, it added.

NFC is expanding its facilities to meet the future requirement of twenty, 700 MWe PHWRs, proposed to be established in a phased manner across the country.

As part of NFC-Kota project with an outlay of Rs 2400 crore is being executed and further augmentation of the existing facilities at Hyderabad campus and Zirconium Complex, Pazhayakayal are also in the offing, the statement said.

​Washington, April 18 (IANS) US researchers have developed a wristband-type wearable sweat sensor that could help diagnose cystic fibrosis, diabetes and other diseases.

The sensor collects sweat, measures its molecular constituents and then electronically transmits the results for analysis and diagnostics through a smartphone, Xinhua news agency reported on Monday.

The study was led by researchers at the Stanford University, in collaboration with the University of California, Berkeley.

Unlike previous sweat collectors, the new device does not require patients to sit still for a long time while it collects sweat from them.

The wearable device is a two-part system of flexible sensors and microprocessors that sticks to the skin, stimulates the sweat glands and then detects the presence of different molecules and ions based on their electrical signals.

High chloride ion levels, for example, are an indicator of cystic fibrosis while high blood glucose levels can indicate diabetes, according to the study published in the US journal Proceedings of the National Academy of Sciences.

Conventional methods for diagnosing cystic fibrosis -- a genetic disease that causes mucus to build up in the lungs, pancreas and other organs -- require that patients visit a specialized centre and sit for 30 minutes while electrodes stimulate sweat glands in their skin to provide sweat for the test.

By comparison, the wearable sweat sensor stimulates the skin to produce minute amounts of sweat, quickly evaluates the contents and beams the data by way of a cellphone to a server that can analyze the results, and this test happens all at once and in real time, said Carlos Milla, Associate Professor at Stanford University. 

For this study, the research team also measured glucose levels in sweat, which correspond to blood glucose levels, making the device potentially useful for monitoring pre-diabetes and diabetes.

But the technology can also be used to measure other molecular constituents of sweat, such as sodium and potassium ions and lactate, meaning the platform can be used to "measure virtually anything found in sweat."

"Sweat is hugely amenable to wearable applications and a rich source of information," said co-author Ronald Davis, Professor at Stanford University.

The team is now working on large-scale clinical studies to look for correlations between sweat-sensor readings and health.

In the longer term, it's hoped that the wearable sensor could be integrated into a smartwatch for broad population monitoring.

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.