Knowledge Update

​Toronto, Nov 17 (IANS) A single bout of sleep apnea - a condition where breathing repeatedly stops and starts during sleep -- impacts your ability to regulate blood pressure, says a study.

Sleep apnea can result in frequent periods of decreased oxygen levels in the body, known as intermittent hypoxia.

Just six hours of the fluctuating oxygen levels associated with sleep apnea can begin to deteriorate a person's circulatory system, the study found.

"While it is well established that sleep apnea is linked to high blood pressure, our study shows this condition has an impact on the cardiovascular system that can begin within a single day," said researcher Glen Foster, Assistant Professor at University of British Columbia's Okanagan campus in Canada.

"After just six hours of fluctuating oxygen levels, similar to what happens with sleep apnea, the body's ability to regulate blood pressure is impaired," Foster noted.

"These changes occurred almost immediately in healthy young adults who were not experiencing the cumulative effects years of sleep apnea could bring about," Foster said.

As part of his study, Foster examined the impact of intermittent hypoxia on the cardiovascular system in a few healthy young adults. 

Study participants wore a ventilating mask for six hours and oxygen levels were altered to mimic sleep apnea symptoms.

The study, published in the American Journal of Physiology, found that sleep apnea compromised the function of a person's baroreceptors--biological sensors that regulate blood pressure. 

It also found damaging blood flow patterns in the legs, which over time could impact vascular health.

"These findings suggest that interventions for people suffering sleep apnea should occur as soon as the condition is diagnosed," Foster said.

​New York, Nov 17 (IANS) High doses of vitamin D are likely to reduce the incidence of acute respiratory illness in older adults, suggests a study led by an Indian-origin researcher.

The study found that among those who took higher doses of vitamin D, there was a 40 per cent reduction in acute respiratory illness -- one of the leading causes of serious illness, debilitation and death among patients in nursing homes and other long-term care facilities.

"Vitamin D can improve the immune system's ability to fight infections because it bolsters the first line of defense of the immune system," said lead author Adit Ginde, professor at the University of Colorado, Denver, US.

"This is a potentially life-saving discovery. There is very little in a doctor's arsenal to battle ARI, especially since most are viral infections where antibiotics don't work. But vitamin D seems able to potentially prevent these infections," Ginde added.

In older people that first line of defence is often impaired. But vitamin D can reinforce it and prevent illnesses like pneumonia, influenza and bronchitis, Ginde said.

It may also prevent infections and exacerbations of chronic obstructive pulmonary disease (COPD) like emphysema.

Conversely, Ginde found that those who received higher doses of vitamin D also saw an increase in falls. 

The falls were lower in those given smaller doses rather than higher monthly doses of vitamin D.

For the study, the team looked at 107 patients with an average age of 84 over a 12 month period. 

Those who received higher doses saw acute respiratory illness cut nearly in half, but also had over double the incidence of falls, the study said.

The study was published in the Journal of the American Geriatrics Society.

​Washington, Nov 17 (IANS) Scientists have discovered a "great valley" in the southern hemisphere of Mercury, providing more evidence that the small planet closest to the sun is shrinking.

Scientists used images from NASA's MESSENGER spacecraft to create a high-resolution topographic map that revealed the broad valley -- more than 1,000 kilometres long -- extending into the Rembrandt basin, one of the largest and youngest impact basins on Mercury. 

"Unlike Earth's Great Rift Valley, Mercury's great valley is not caused by the pulling apart of lithospheric plates due to plate tectonics; it is the result of the global contraction of a shrinking one-plate planet," said lead author of the study Tom Watters, senior scientist at the Smithsonian National Air and Space Museum in Washington, D.C. 

About 400 kilometres wide and three kilometres deep, Mercury's great valley is smaller than Mars' Valles Marineris, but larger than North America's Grand Canyon and wider and deeper than the Great Rift Valley in East Africa, said the study published in the journal Geophysical Research Letters.

Mercury's great valley is bound by two large fault scarps ? cliff-like landforms that resemble stair steps. 

The scarps formed as Mercury's interior cooled and the planet's shrinking was accommodated by the crustal rocks being pushed together, thrusting them upward along fault lines, the study said.

NASA's MErcury Surface, Space ENvironment, Geochemistry and Ranging (MESSENGER) mission was launched on August 3, 2004 to understand Mercury, the smallest, densest and least-explored of the terrestrial planets.

​Berlin, Nov 15 (IANS) The German economic growth rose slightly in the third quarter of 2016, official data showed on Tuesday.

Germany's gross domestic product (GDP) increased by 0.2 per cent quarter on quarter, Xinhua news agency quoted German federal statistics office Destatis as saying.

​San Francisco, Nov 16 (IANS) At a time when governments and enterprises the world over are brainstorming over ways to secure their data on the Cloud platform, a right mix of security in both hardware and software is the key to ward off hackers and minimise cyber attacks, a top security expert has reiterated.

​London, Nov 16 (IANS) Brexit could be delayed by months, even as long as two years, after a Supreme Court judge of Britain suggested that "comprehensive" legislation was required to trigger Article 50.

San Francisco, Nov 16 (IANS) In a move to "democratise" artificial intelligence (AI) and making it accessible to everyone, Microsoft has teamed up with OpenAI, a non-profit AI research organisation co-founded by Elon Musk.

​New York, Nov 16 (IANS) Set to become one of the highest-profile stock debuts along with Chinese e-commerce company Alibaba and social media giant Facebook, photo and video sharing app Snap Inc has filed paperwork for an initial public offering (IPO) that may value the messaging platform at as much as $25 billion, media reported.

​New York, Nov 16 (IANS) Researchers at The Rockefeller University in New York said they discovered two promising new antibiotics by sifting through the human microbiome with the help of a software.

​London, Nov 16 (IANS) Love to binge on fatty foods such as oily samosas and cheese-laden pizzas? Beware, as a new study warns that such children may be at risk of developing cognitive and psychiatric problems such as schizophrenia or Alzheimer's disease in their adulthood. According to the study, diets rich in fat deplete the levels of a key protein known as reelin which help synapses in the brain to work properly. This hampers behavioural flexibility and memory. Low levels of reelin have been associated with a higher risk of developing Alzheimer's disease in later life. "These changes from a young age onwards are more the result of the fatty foods themselves, and the impact they have on young brains, rather than arising from the mere fact of being obese," said Urs Meyer from ETH Zurich in Switzerland. The authors focused on a prefrontal cortex -- a brain region -- associated with the planning of complex actions and decision making, expressing one's personality and controlling one's social behaviour. Adolescents eating high-fat diets were found to have cognitive deficits due to the immature character of the prefrontal cortex during this time frame. "We saw that plasticity in the prefrontal cortex was impaired in animals fed high-fat foods during adolescence and quite remarkably we then observed that when restoring reelin levels, both synaptic plasticity and cognitive functions went back to normal," explained Pascale Chavis from the INMED Institute in France. A careful nutritional balance during this sensitive period is pivotal for reaching the full capacity of adult prefrontal functions, the researchers said, in the paper published in the journal "Molecular Psychiatry".