Knowledge Update

New York, March 18 (IANS) Children with chronically disrupted sleep are likely to have defects in their brain cells that are associated with mental skills, mood and behaviour, researchers have warned.

Obstructive sleep apnea is a common sleep disturbance which affects up to five per cent of all children. 

The findings showed that children between 7 and 11 years of age who had moderate or severe obstructive sleep apnea showed significant reductions of gray matter -- brain cells involved in movement, memory, emotions, speech, perception, decision making and self-control.

Further, there is also a strong connection between sleep apnea and the loss of neurons or delayed neuronal growth in the developing brain.

"The images of gray matter changes are striking. There is also clear evidence of widespread neuronal damage or loss compared to the general population," said Leila Kheirandish-Gozal, Director at the University of Chicago in the US. 

For this study, published in the journal Scientific Reports, the team evaluated sleep patterns of 16 children with obstructive sleep apnea (OSA). 

Each child also went through neuro-cognitive testing and had his or her brain scanned with non-invasive magnetic resonance imaging (MRI).

They found reductions in the volume of gray matter in multiple regions of the brains of children with disrupted sleep. 

These included the frontal cortices -- which handle movement, problem solving, memory, language, judgement and impulse control -- the prefrontal cortices -- complex behaviours, planning, personality -- parietal cortices -- integrating sensory input -- temporal lobe -- hearing and selective listening -- and the brainstem -- controlling cardiovascular and respiratory functions.

This extensive reduction of gray matter in children with a treatable disorder provides one more reason for parents of children with symptoms of sleep apnea to consider early detection and therapy, the researchers noted.

​Tokyo, March 18 (IANS) A laboratory at a university in Japan will restart its research nuclear reactor, the first ever in the country, in April after meeting safety standards. the media reported on Saturday.

It will be the first research reactor in Japan to go back online under stringent regulations introduced by the government in the wake of the 2011 Fukushima Daiichi nuclear accident that was triggered after the massive earthquake and tsunami, public broadcaster NHK reported.

Kindai University in Higashi-Osaka said on Friday that the reactor has passed a series of checks by Japan's nuclear regulator.

The Nuclear Regulation Authority gave in-principle approval for the restart of the reactor in May last year. 

The university subsequently made further adjustments to protect against fire, tornados and other risks.

The small reactor has a maximum output of just 1 watt, and is used exclusively for academic purposes.

New York, March 17 (IANS) People who examine an issue virtually as a debate or dialogue between two sides are more likely to have deeper, more sophisticated reasoning skills, according to new research.

The research findings showed that envisioning opposing views leads to a more comprehensive examination of the issue. 

Moreover, constructing opposing views leads people to regard knowledge less as fact and more as information that can be scrutinised in a framework of alternatives and evidence.

"Constructing a dialogue would lead to deeper, more comprehensive processing of the two positions and hence a richer representation of each and the differences between them... thus helping to expand and sharpen students' thinking," said Deanna Kuhn of Columbia University in New York. 

"Everything possible should be done to encourage and support genuine discourse on critical issues, but our findings suggest that the virtual form of interaction may be a productive substitute, at a time when positions on an issue far too often lack the deep analysis to support them," Kuhn added. 

For the study, published in the journal Psychological Science, the team asked 60 undergraduates to participate in a one-hour writing activity. Some participants were randomly assigned to construct a dialogue between TV commentators discussing two mayoral candidates.

They received a list of notable problems that the city was facing and a list of actions proposed by each candidate to solve these problems. 

Other participants received the same information about the city and the candidates but were asked to write a persuasive essay highlighting the merits of each candidate instead. 

Then, participants in both groups were asked to write a script for a two-minute TV spot, promoting their preferred candidate.

The results showed that participants who had constructed a dialogue included more discrete ideas in their writing.

​London, March 17 (IANS) Researchers have found that the absence of a protein could trigger obsessive-compulsive disorder (OCD) that can lead to repetitive ritualised behaviour such as washing hands or body time and again.

"We were able to show in mouse models that the absence of the protein SPRED2 alone can trigger an excessive grooming behaviour," said Professor Kai Schuh from the Institute of Physiology at the Julius-Maximilians-Universitat (JMU) Wurzburg in Bavaria, Germany.

Schuh believes that this finding is crucial as no clear trigger for this type of disorder has been identified until now. 

Previous research pointed to multiple factors being responsible for developing OCD.

Occurring in all cells of the body, the protein SPRED2 is found in particularly high concentrations in regions of the brain, namely in the basal ganglia and the amygdala.

Normally, the protein inhibits an important signal pathway of the cell, the so-called Ras/ERK-MAP kinase cascade. When it is missing, this signal pathway is more active than usual.

The findings could lead to new treatment for the disorder characterised by persistent intrusive thoughts.

Like depression, eating disorders and other mental diseases, OCD is treated with anti-depressants. 

However, the drugs are non-specific, that is they are not tailored to the respective disease. 

Therefore, scientists have been looking for new and better targeted therapies that have fewer side effects.

"Our study delivers a valuable new model that allows the disease mechanisms to be investigated and new therapy options for obsessive-compulsive disorders to be tested," Schuh said.

Beijing, March 17 (IANS) Researchers from China, New Zealand and the US have found four intact mushroom fossils, sources said on Friday.

The four, well preserved in Burmese amber (fossilised sap of extinct trees) for at least 99 million years, are the earliest complete mushroom fossils ever found, according to the sources with the Chinese Academy of Sciences.

The findings represent four species of mushroom. A stalk and a complete cap containing distinct gills are visible in most of the mushrooms, which are two to three mm long, Xinhua news agency reported.

The research team led by professor Huang Diying from Nanjing Institute of Geology and Paleontology, reported the finding after researching more than 20,000 pieces of Burmese amber collected over 10 years.

The discovery highlights the palaeo-diversity of mushrooms, pushing back the presence of agaric mushrooms by at least 25 million years.

Mushrooms are common and morphologically diverse fungi. Their bodies are soft and ephemeral and therefore extremely rare in fossils. 

Until the recent discovery, only five species of mushrooms were known exclusively from amber.

​New York, March 17 (IANS) More than 50 per cent of millennials in the US prefer checking Snapchat first over other social media platforms such as Facebook, Instagram, and LinkedIn, the results of a new survey suggest.

The survey involving nearly 10,000 college students found that 58 per cent of them check Snapchat over Facebook, Instagram, and LinkedIn combined. 

Instagram accounted for 27 per cent, Facebook for 13 per cent, and LinkedIn for two per cent, or a total of 42 per cent, showed the new data gathered by LendEDU, an online marketplace for student loans and student loan refinancing.

The findings suggest that Snap Inc., parent company of messaging app Snapchat, may not only survive the volatile Wall Street environment, but prosper.

Snap Inc has been the word on Wall Street since it went public on March 2.

Snap rode its immense popularity to produce eye-popping numbers during its initial offering, with a first day closing price at $24.53. 

In the days following the IPO, shares of Snap traded lower as exuberance and volume settled. 

But the messaging app's popularity among millenials (born between 1980 and and early 2000s)can help the company prosper in the stock market, according to the new results.

"Overall, Snap's access and importance to millennials will be the driving force behind their success in the stock market," LendEDU said in a report on Thursday.

For the study, LendEDU has gathered this data under license from polling company WhatsGoodly.

According to Snap, the majority of Snapchat users are aged 18-to-34 years old. On an average, these users visit the app 18 times a day for a combined 25 to 30 minutes. 

Additionally, users younger than 25 visit the application more than 20 times a day for more than 30 minutes.

New York, March 16 (IANS) Scientists have developed a new pill that can act as non-invasive alternative to colonoscopies -- an effective way to screen for colon cancer -- and help identify growths called polyps.

Colorectal cancer is the third-leading cause of cancer deaths in women and second leading cause in men. Early detection and screening are essential to reduce the rates of colorectal cancer.

The pill -- PillCam Colon 2 -- contains two miniature cameras on either end. After being ingested by the patient, the capsule travels through the digestive tract, captures images and wirelessly transmits them to a recorder the patient wears on a belt.

Like a colonoscopy, the system can help identify growths called polyps, said researchers from Loyola University in Chicago, US.

During a standard colonoscopy, a flexible tube (colonoscope) is inserted into the rectum and guided by a physician through the colon. A camera at the end of the colonoscope allows for visualisation of polyps.

However, some patients cannot tolerate the procedure, or may be at higher risk for sedation, the researchers said.

With the new system, the patient swallows the capsule with water. After the non-reusable capsule is excreted, it's flushed down the toilet. The patient returns the recorder to the physician's office. If a polyp is found, the patient arranges to undergo a colonoscopy to remove the growth.

"Early detection has been proven to save lives, and the video capsule system offers a convenient screening test for people who are unable to have a complete colonoscopy," Mukund Venu from Loyola University, said in a statement.

The US Food and Drug Administration approved the capsule system for patients whose anatomy of the colon makes it difficult to guide a colonoscope through the entire colon and for patients who have elevated risk of complications due to age or other reasons.

New York, March 16 (IANS) A common genetic variant that accelerates normal brain ageing in older people by up to 12 years has been identified by US researchers.

The findings could point towards a novel biomarker for the evaluation of anti-ageing interventions and highlight potential new targets for the prevention or treatment of age-associated brain disorders such as Alzheimer's disease, the researchers said.

"If you look at a group of elderly, some will look older than their peers and some will look younger. The same differences in ageing can be seen in the frontal cortex, the brain region responsible for higher mental processes," said Asa Abeliovich, Professor at Columbia University Medical Centre (CUMC) in the US.

The results, published in the journal Cell Systems, showed that many of these differences are tied to variants of a gene called TMEM106B. About one-third of people have two copies of TMEM106B and another third have one copy.

People who have two 'bad' copies of this gene have a frontal cortex that, by various biological measures, tends to appear 12 years older than those who have two normal copies.

"TMEM106B begins to exert its effect once people reach age 65. Until then, everybody's in the same boat, and then there's some yet-to-be-defined stress that kicks in. If you have two good copies of the gene, you respond well to that stress. If you have two bad copies, your brain ages quickly," Abeliovich explained.

"It's in healthy tissue that you start to get disease. It appears that if you have these genetic variants, brain ageing accelerates and that increases vulnerability to brain disease. And vice versa: if you have brain disease, the disease accelerates brain ageing," he noted. 

New York, March 15 (IANS) Scientists have developed a high-resolution retinal prosthesis using nanowires and wireless electronics that may aid neurons in the retina to respond to light.

The technology could help tens of millions of people worldwide suffering from neurodegenerative diseases that affect eyesight, including macular degeneration, retinitis pigmentosa and loss of vision due to diabetes.

In the study, detailed in the Journal of Neural Engineering, the researchers demonstrated this response to light in a rat retina interfacing with a prototype of the device in vitro.

"We want to create a new class of devices with drastically improved capabilities to help people with impaired vision," said Gabriel A. Silva, Professor at the University of California San Diego in the US.

The new prosthesis relies on two ground-breaking technologies. One consists of arrays of silicon nanowires that simultaneously sense light and electrically stimulate the retina accordingly.

The nanowires give the prosthesis higher resolution than anything achieved by other devices -- closer to the dense spacing of photoreceptors in the human retina. 

The other is a wireless device that can transmit power and data to the nanowires over the same wireless link at record speed and energy efficiency.

Further, the new system does not require a vision sensor outside of the eye to capture a visual scene and then transform it into alternating signals to sequentially stimulate retinal neurons.

Instead, the silicon nanowires mimic the retina's light-sensing cones and rods to directly stimulate retinal cells.

Nanowires are bundled into a grid of electrodes, directly activated by light and powered by a single wireless electrical signal. 

The power provided to the nanowires from the single wireless electrical signal gives the light-activated electrodes their high sensitivity while also controlling the timing of stimulation.

Seoul, March 15 (IANS) Challenging a commonly held theory that changes in the Earth's orbit triggered Sahara desertification, a new study suggests that humans may have played an active role in the transition of a lush green landscape into the world's largest hot desert thousands of years ago.

The desertification of the Sahara has long been a target for scientists trying to understand climate and ecological tipping points. 

Most studies done to date point to changes in the Earth's orbit or natural changes in vegetation as the major driving forces.

In a new paper published in the journal Frontiers in Earth Science, David Wright from Seoul National University in South Korea challenges the conclusions of these studies.

"In East Asia there are long established theories of how Neolithic populations changed the landscape so profoundly that monsoons stopped penetrating so far inland," said Wright. 

Evidence of human-driven ecological and climatic change has been documented in Europe, North America and New Zealand, said Wright who believed that similar scenarios could also apply to the Sahara.

To test his hypothesis, Wright reviewed archaeological evidence documenting the first appearances of pastoralism across the Saharan region, and compared this with records showing the spread of scrub vegetation, an indicator of an ecological shift towards desert-like conditions. 

The findings confirmed his thoughts.

Beginning approximately 8,000 years ago in the regions surrounding the Nile River, pastoral communities began to appear and spread westward, increasing at the same time the spread of scrub vegetation, the study said.

Growing agricultural addiction had a severe effect on the region's ecology. As more vegetation was removed by the introduction of livestock, it increased the albedo (the amount of sunlight that reflects off the earth's surface) of the land, which in turn influenced atmospheric conditions sufficiently to reduce monsoon rainfall. 

The weakening monsoons caused further desertification and vegetation loss, promoting a feedback loop which eventually spread over the entirety of the modern Sahara, the study said.