Knowledge Update

New York, Feb 5 (IANS) A pacemaker similar to the size of a nickel can be implanted in patients to restore the heart's normal rhythm, when it is unable to pump enough oxygen-rich blood, experts have said.

Pacemakers are the most common way to treat bradycardia to help restore the heart's normal rhythm and relieve symptoms by sending electrical impulses to the heart to increase the heart rate.

Houston Methodist Hospital in Texas is now offering a US Food and Drug Administration (FDA) approved Micra Transcatheter Pacing System (TPS) -- the world's smallest pacemaker for patients with bradycardia, a condition characterized by a slow heart rate, usually fewer than 60 beats per minute.

The device is the size of a large vitamin, and unlike traditional pacemakers, it does not require cardiac wires (leads) or a surgical "pocket" under the skin to deliver a pacing therapy.

"The device is small enough to be delivered through a catheter and implanted directly into the heart, providing a safe alternative to conventional pacemakers without the complications associated with leads," said Paul Schurmann, Managing Director at Houston Methodist Hospital.

"The device also allows us to automatically adjust pacing therapy based on a patient's activity levels and another positive is the battery can last up to 10 years," added Schurmann.

Micra TPS was designed with a unique feature that enables it to be permanently turned off so it can remain in the body and a new device can be implanted without risk of electrical interaction.

​New York, Feb 5 (IANS) Ever wondered what happens on the other side of our skulls when we hit our heads? Now, the world's first tiniest hammer being developed by the US researchers may help understand what happens when force is applied to brain cells, an advance that may help improve treatments for brain injuries as well as Alzheimer's disease.

The "microHammer" -- a tiny cellular-scale machine -- can be used to tap, strike, squeeze and poke individual neural progenitors to elicit responses to unlock the mysteries of the brain.

The device flows through individual cells and subjects each of them to one of a variety of physical forces, the researchers said.

"The microhammer will enable precision measurements of the physical, chemical and biological changes that occur when cells are subjected to mechanical loading, ranging from small perturbations to high-force, high-speed impacts," Megan Valentine from University of California - Santa Barbara, said in a statement. 

The microhammer is currently undergoing the process of characterisation, whereby the types and magnitudes of forces it can apply are being measured and recorded in anticipation of the first set of neuron-smashing experiments.

The microhammer will provide new insight into the causes and progress of brain injuries due to trauma.

It could also pave the way toward a better understanding of neural conditions such as Alzheimer's disease as well as traumatic brain injury -- a currently incurable and often insidious condition -- that affects everyone from soldiers, to athletes in contact sports, to anyone who has an accident, Valentine said.

New York, Feb 4 (IANS) Eating grapes daily can help protect the brain against early decline associated with Alzheimer's disease, show results of a pilot study involving people with early memory decline.

Alzheimer's disease is a brain disease that results in a slow decline of memory and cognitive skills. 

"The study examines the impact of grapes as a whole fruit versus isolated compounds and the results suggest that regular intake of grapes may provide a protective effect against early decline associated with Alzheimer's disease," said lead investigator of the study Daniel Silverman from University of California Los Angeles, US.

"This pilot study contributes to the growing evidence that supports a beneficial role for grapes in neurologic and cardiovascular health, however more clinical studies with larger groups of subjects are needed to confirm the effects observed here," Silverman added.

The study results, published in Experimental Gerontology, showed a grape-enriched diet protected against the decline of metabolic activity. 

Low metabolic activity in these areas of the brain is a hallmark of early stage Alzheimer's disease. 

Additionally, those consuming a grape-enriched diet also exhibited increased metabolism in other areas of the brain that correlated with individual improvements in attention and working memory performance, compared to those on the non-grape diet. 

In the study, participants with early memory decline were randomly selected to receive either whole grape powder -- equivalent to just a little over two cups of grapes per day -- or a polyphenol-free placebo powder matched for flavour and appearance. 

Cognitive performance was measured at baseline and six months later. Changes in brain metabolism, assessed by brain scans, were also measured at baseline and six months later. 

The results showed that consuming grapes preserved healthy metabolic activity in the regions of the brain that are affected by the earliest stages of Alzheimer's disease, where metabolic decline takes hold. 

Participants who did not consume grapes exhibited significant metabolic decline in these critical regions. 

Grape polyphenols help promote antioxidant and anti-inflammatory activities. 

Previous research had shown that grapes may help support brain health by working in multiple ways - from reducing oxidative stress in the brain to promoting healthy blood flow in the brain to helping maintain levels of a key brain chemical that promotes memory to exerting anti-inflammatory effects.

​New York, Feb 4 (IANS) Challenging a common perception that personality traits are ingrained, researchers have found that when preschoolers spend time around one another, they tend to take on each others' personalities.

The study, published online in the Journal of Personality and Social Psychology, suggests personality is shaped by environment and not just genes.

"Our finding, that personality traits are 'contagious' among children, flies in the face of common assumptions that personality is ingrained and can't be changed," said co-investigator on the study Jennifer Watling Neal, Associate Professor at Michigan State University in the US.

"This is important because some personality traits can help children succeed in life, while others can hold them back," she explained. 

For the study, the researchers studied two preschool classes for an entire school year, analysing personality traits and social networks for one class of three-year-olds and one class of four-year-olds.

Children whose play partners were extroverted or hard-working became similar to these peers over time. 

Children whose play partners were over-anxious and easily frustrated, however, did not take on these particular traits, the study said.

Washington, Feb 3 (IANS) The dwarf planet Ceres may actually host many "hidden" ice volcanoes, besides the only one discovered recently, a study says.

NASA's Dawn spacecraft discovered Ceres's four-kilometre tall Ahuna Mons cryovolcano in 2015. 

Other icy worlds in our solar system, like Pluto, Europa, Triton, Charon and Titan, may also have such mountains of icy rock -- called cryovolcanoes -- but Ahuna Mons is conspicuously alone on Ceres. 

Now, in a paper accepted for publication in the journal Geophysical Research Letters, scientists showed there might have been cryovolcanoes other than Ahuna Mons on Ceres millions or billions of years ago, but these cryovolcanoes might have flattened out over time and become indistinguishable from the planet's surface. 

"We think we have a very good case that there have been lots of cryovolcanoes on Ceres but they have deformed," said lead study author Michael Sori of Lunar and Planetary Laboratory at University of Arizona in Tucson, US.

Ahuna Mons is a prominent feature on Ceres, rising to about half the height of Mount Everest. Its solitary existence has puzzled scientists since they spied it.

Adding to the puzzle are the steep sides and well-defined features of Ahuna Mons -- usually signs of geologic youth, Sori said. 

That leads to two possibilities. Ahuna Mons is just as it appears, inexplicably alone after forming relatively recently on an otherwise inactive world. Or, the cryovolcano is not alone or unusual, and there is some process on Ceres that has destroyed its predecessors and left the young Ahuna Mons as the solitary cryovolcano on the dwarf planet, according to Sori.

Ceres has no atmosphere, so the processes that wear down volcanoes on Earth -- wind, rain and ice -- are not possible on the dwarf planet. 

Sori and his colleagues hypothesised that another process, called viscous relaxation, could be at work.

Viscous relaxation is the idea that just about any solid will flow, given enough time. For example, a cold block of honey appears to be solid. But if given enough time, the block will flatten out until there is no sign left of the original block structure.

On Earth, viscous relaxation is what makes glaciers flow, Sori explained. 

"Ahuna Mons is at most 200 million years old. It just has not had time to deform," Sori said.

The researchers said they would next try and identify the flattened remnants of older cryovolcanoes on Ceres. 

The findings could help scientists better decipher the history of how the dwarf planet formed, Sori added.

​New York, Feb 3 (IANS) Sleep may be regulated in part by several brain-based immune proteins, says a study that could pave the way for new therapies to treat chronic sleep disorders and sleep disturbances secondary to other diseases.

The immune proteins -- collectively called inflammasome NLRP3 -- recruit a sleep-inducing molecule to trigger somnolence following sleep deprivation and exposure to a bacterial toxin, showed results of the study published in the journal Brain, Behavior, and Immunity.

Animals lacking genes for this protective immune complex showed profound sleep aberrations.

"Our research points, for the first time, to the inflammasome acting as a universal sensing mechanism that regulates sleep through the release of immune molecules," said study senior investigator Mark Zielinski from Harvard Medical School. 

In a series of experiments, the scientists demonstrated that following sleep deprivation or exposure to bacteria, the inflammasome activates an inflammatory molecule called interleukin-1 beta, known to induce sleep and promote sleep intensity. 

The brain cells of mice lacking the gene coding for inflammasome NLRP3 showed a marked absence of this sleep-inducing molecule.

Going a step further, the investigators compared the behaviour, sleep patterns and electrical activity in the brains of mice lacking the inflammasome gene to those in a group of mice with intact inflammasome genes.

Mice lacking the inflammasome gene had abnormal sleep responses following sleep deprivation. 

On average, such mice slept less and experienced more sleep interruptions than mice with their genes intact.

The latter group also slept more and harder following bacterial exposure -- the expected physiological response following infection, the researchers said.

Tokyo, Feb 3 (IANS) Examining a molecular cloud with enigmatic motion, a team led by researchers in Japan has found signs of stray black hole hiding in the Milky Way.

It is difficult to find black holes, because they are completely black. In some cases black holes cause effects which can be seen. 

Theoretical studies have predicted that 100 million to one billion black holes should exist in the Milky Way, although only 60 or so have been identified through observations to date. 

"We found a new way of discovering stray black holes," said one of the researchers Tomoharu Oka, Professor at Keio University in Japan.

The researchers used the ASTE Telescope in Chile and the 45-m Radio Telescope at Nobeyama Radio Observatory, both operated by the National Astronomical Observatory of Japan, to observe molecular clouds around the supernova remnant W44, located 10,000 light-years away from us. 

A supernova is the explosion of a star -- the largest explosion that takes place in space, according to NASA.

The primary goal of the researchers was to examine how much energy was transferred from the supernova explosion to the surrounding molecular gas, but they happened to find signs of a hidden black hole at the edge of W44, said the study published in Astrophysical Journal Letters.

During the survey, the team found a compact molecular cloud with enigmatic motion. 

To investigate the origin of this cloud, named the "Bullet", the team performed intensive observations of the gas cloud.

The data indicated that the Bullet seems to jump out from the edge of the supernova remnant with immense kinetic energy. 

"Most of the Bullet has an expanding motion with a speed of 50 km/s, but the tip of the Bullet has a speed of 120 km/s," Masaya Yamada, a graduate student at Keio University, said.

"Its kinetic energy is a few tens of times larger than that injected by the W44 supernova. It seems impossible to generate such an energetic cloud under ordinary environments," Yamada added.

The researchers believe that a dark and compact gravity source, possibly a black hole, has an important role in the formation of the Bullet.

​New York, Feb 1 (IANS) It is true that money does not grow on trees but electricity might someday, as scientists have developed a prototype biomimetic tree that mimics the branches and leaves of a cottonwood tree and generates electricity when its artificial leaves sway in the wind.

Researchers from Iowa State University found that the technology could spawn a niche market for small and visually unobtrusive machines that turn wind into electricity.

"The possible advantages here are aesthetics and its smaller scale, which may allow off-grid energy harvesting. We set out to answer the question of whether you can get useful amounts of electrical power out of something that looks like a plant," said Michael McCloskey, associate professor at Iowa University.

Cell phone towers in some urban locations, such as Las Vegas, have been camouflaged as trees, complete with leaves that serve only to improve the tower's aesthetic appeal. 

"Tapping energy from those leaves would increase their functionality," McCloskey said.

This prototype device features a metallic trellis, from which hang a dozen plastic flaps in the shape of cottonwood leaves.

"It's definitely doable, but the trick is accomplishing it without compromising efficiency. More work is necessary, but there are paths available," said Curtis Mosher of Iowa State University. 

In a paper published in the journal PLOS ONE, the researchers explained that small strips of specialised plastic inside the leaf stalks release an electrical charge when bent by wind.

​London, Feb 2 (IANS) Scientists have identified new ways to provide vaccines against polio which do not require the growth of live virus for their manufacture, thereby reducing risk of virus escaping into the environment.

Polio is on the verge of being eradicated world-wide, but even when it has been officially declared as extinct as a disease, governments will need to continue to vaccinate to ensure against it recurring.

Using current technology, the production of vaccine requires the growth of enormous quantities of live virus, which is then chemically killed, thus presenting a dangerous security risk of virus escaping into the environment.

"Continuing to vaccinate after polio has been eradicated is essential to ensure against the disease recurring, but there are significant biosafety concerns about current production methods," said co-leader of the study David Rowlands, Professor of Molecular Virology at University of Leeds in Britain.

"Our new method of creating the vaccine has been proven to work in lab conditions and on top of that we've proved it's actually more stable than existing vaccines," Rowlands said.

Despite the success of vaccines produced from 'virus-like particles' (VLPs) for hepatitis B and human papilloma viruses, poliovirus VLPs have proved to be too unstable to make practical vaccines.

The research team found a new way to modify these VLPs, also known as 'empty capsids' by identifying mutations which make their structures sufficiently stable to act as vaccines.

The empty capsids change shape when warmed and become unusable as vaccines, but the mutations identified in this research prevent these damaging changes.

These new stabilised VLPs are suitable as replacements for the current killed poliovirus vaccines and can be produced in ways that do not require the growth of live virus, said the study published in the Journal of Virology.

Using the newly developed stabilised VLPs would be best used after the virus has been eradicated, the researchers said.

This study was a lab experiment, which shows stabilised VLPs to be effective in a controlled environment. 

Further research using animals (rats and mice) is planned, as part of the essential process of making sure the new VLPs are safe and effective for use in humans, the researchers said.