Knowledge Update

​New York, April 21 (IANS) Traditional clinical hearing tests often fail to detect patients with a common form of inner ear damage that might otherwise be detected by more challenging behavioural tests, new research has found.

Such tests may not be able to diagnose those facing problems in certain situations, like hearing speech in a noisy room, said the study published in the journal Frontiers in Neuroscience.

This type of "hidden hearing loss" presents itself as essentially normal hearing in the clinic, where audiograms -- the gold-standard for measuring hearing thresholds -- are typically conducted in a quiet room.

The reason some forms of hearing loss may go unrecognised in the clinic is that hearing involves a complex partnership between the ear and the brain. 

It turns out that the central auditory system can compensate for significant damage to the inner ear by turning up its volume control, partially overcoming the deficiency, said the study's lead author Richard Salvi, Director, Centre for Hearing and Deafness at University at Buffalo, New York.

"You can have tremendous damage to inner hair cells in the ear that transmit information to the brain and still have a normal audiogram," he said. 

"But people with this type of damage have difficulty hearing in certain situations, like hearing speech in a noisy room. Their thresholds appear normal. So they're sent home," Salvi said.

Ear damage reduces the signal that goes the brain. That results in trouble hearing, but that's not what's happening here, because the brain "has a central gain control, like a radio, the listener can turn up the volume control to better hear a distant station", Salvi added.

​Geneva, April 20 (IANS) Remarkable achievements have been made in tackling neglected tropical diseases (NTDs) since 2007 with one billion people receiving treatment in 2015 alone, World Health Organization (WHO) said on Wednesday in a report.

"WHO has observed record-breaking progress towards bringing ancient scourges like sleeping sickness and elephantiasis to their knees," Xinhua news agency quoted WHO Director-General Margaret Chan, as saying.

The WHO report, Integrating Neglected Tropical Diseases in Global Health and Development, demonstrates how strong political support, generous donations of medicines, improvements in living conditions, have led to sustained expansion of disease control programmes in countries where these diseases are most prevalent.

The report documented one billion people treated for at least one neglected tropical disease in 2015 alone as one of key achievements against NTDs.

However, the report highlighted the need to further scale up action in other areas.

"Further gains in the fight against neglected tropical diseases will depend on wider progress towards the Sustainable Development Goals," said Dirk Engels, Director of the Department of Control of Neglected Tropical Diseases.

WHO estimated that 2.4 billion people still lack basic sanitation facilities such as toilets and latrines, while more than 660 million continue to drink water from "unimproved" sources, such as surface water.

​London, April 20 (IANS) An international team of astronomers has discovered a so-called "super-Earth" that could contain liquid water, a situation that would make it a very good candidate for harbouring life.

Super-Earth is a rocky, temperate planet orbiting a red dwarf star, Efe news agency reported.

In an article published on Wednesday in Nature magazine, the scientists say that the distant planet, dubbed LHS 1140b, is orbiting an M class red dwarf star a little smaller and dimmer than the Sun but the most common type of star in our galaxy.

The super-Earth and its parent star are located in the constellation Cetus, the Whale, 39 light years from the Sun, thus -- relatively speaking -- putting it in our galactic "neighbourhood," according to Felipe Murgas, the coauthor of the study and a researcher with Spain's Canary Islands Institute of Astrophysics.

The study's main author, Jason Dittmann, with the Harvard-Smithsonian Centre for Astrophysics, said that this is the "most interesting" exoplanet that he's seen in the last decade.

The new planet was discovered thanks to the MEarth-South telescope network devoted exclusively to seeking out exo-planets.

The MEarth-South instruments enabled scientists to measure the planet's diameter and, using the HARPS spectrograph at the LaSilla ESO Observatory in Chile, they also were able to measure its mass, density and orbital period.

According to the measurements, LHS 1140b has a diameter 1.4 times that of Earth and a mass 6.6 times that of our own planet.

But more important than that are the climatological conditions, and its orbital distance from its star puts LHS 1140b in the "habitable zone" - thus meaning that the planet's surface temperature allows water to exist in all three of its states: liquid, solid and as a gas.

Whether there is actually water on the planet or not depends on the composition of its atmosphere and other factors, including the presence of a magnetic field, such as the one Earth has, but the most important thing is for the planet to "fulfil the requirements to have water," which means that it must be in its star's habitable zone, Murgas said.

Regarding the age of the planet, the authors of the study said that it probably formed in a manner similar to Earth and its star is probably 5 billion years old, about the same age as the Sun, although the age of M-class stars is hard to determine for a variety of factors, the Spanish researcher added.

In the coming decades, LHS 1140b is sure to be investigated much more intensively, an ongoing project for the powerful next-generation telescopes, including the James Webb instrument and the E-ELT device, which will be installed in Chile and -- within a few years -- will be able to study the system and try to detect its atmosphere, along with other characteristics.

​Thiruvananthapuram, April 19 (IANS) A component of the skin mucus secreted by a frog species found in India can be harnessed to kill influenza viruses, new research has found.

In their experiment, the researchers found that when delivered intranasally, one of the antiviral peptides found in skin secretions from the Indian frog Hydrophylax bahuvistara can kill H1 variety of influenza viruses that can affect humans.

The research, carried out by researchers from Emory University in the US and Rajiv Gandhi Centre for Biotechnology in Thiruvananthapuram, also showed that the compound can protect unvaccinated mice against a lethal dose of some flu viruses. 

The researchers believe that the compound has the potential to contribute to first-line anti-viral treatments during influenza outbreaks.

Frogs' skins were known to secrete "host defense peptides" that defend them against bacteria. 

The new finding, published in the journal Immunity, suggests that the peptides represent a resource for antiviral drug discovery as well.

Anti-flu peptides could become handy when vaccines are unavailable, in the case of a new pandemic strain, or when circulating strains become resistant to current drugs, said senior author Joshy Jacob, Associate Professor of Microbiology and Immunology at Emory Vaccine Center and Emory University School of Medicine in in Atlanta, Georgia, US.

Jacob and his colleagues named the antiviral peptide they identified urumin, after a whip-like sword called "urumi" used in southern India centuries ago. 

Urumin was collected for the study after mild electrical stimulation of the frog.

Peptides are short chains of amino acids, the building blocks of proteins. Some anti-bacterial peptides work by punching holes in cell membranes, and are thus toxic to mammalian cells, but urumin was not.

Instead, urumin appeared to only disrupt the integrity of flu virus, as seen through electron microscopy. 

It binds the stalk of hemagglutinin, a less variable region of the flu virus that is also the target of proposed universal vaccines, the study said.

This specificity could be valuable because current anti-influenza drugs target other parts of the virus, Jacob said.

Urumin was specific for H1 strains of flu, such as the 2009 pandemic strain, and was not effective against other current strains such as H3N2, the study pointed out.

​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.