Knowledge Update

​Washington, May 10 (IANS) Researchers have discovered how a small brain structure plays a central role in the many decisions that we make each day such as what to order for lunch or whether to go with the hearty red wine or the lighter white.

Studying how monkeys choose between juice drinks, the researchers found that some of the neurons in the orbitofrontal cortex (OFC) assign value to the options, while other neurons are related to making final choices. 

All of these neurons can re-map to make different decisions when circumstances change.

"When we choose between an apple and a banana, some neurons assign a value to the apple, some neurons assign a value to the banana, and other neurons represent the choice outcome," said the study's senior investigator Camillo Padoa-Schioppa from Washington University School of Medicine in St. Louis.

"Taken together, these different groups of cells seem to form a neural circuit that generates economic decisions," Padoa-Schioppa said.

In this study, reported in the journal Nature Neuroscience, the researchers examined how this neural circuit reorganises when decisions are made in different circumstances.

During the experiments, the researchers used a dozen different juice drinks. In each tasting session, the monkeys chose between two different drinks. Subsequently, they chose between two other juice drinks.

"If we look at individual cells, neurons are very flexible," Padoa-Schioppa said.

"However, if we consider the whole network, the decision circuit is remarkably stable. This combination of circuit stability and neuronal flexibility makes it possible for the same brain region to generate decisions between any two goods," Padoa-Schioppa noted.​

​London, May 10 (IANS) Scientists have found that upon deprivation of food a certain protein is produced that adjusts the metabolism in the liver, assisting in warding off fatty liver disease.

According to researchers, a reduced intake of calories, such as in the framework of an intermittent fasting diet, can help to whip the metabolism back into shape. 

The findings showed that during fasting, the stress molecule reduces the absorption of fatty acids in the liver and improves sugar metabolism.

In the study, published in the open access journal EMBO Molecular Medicine, the researchers found that during fasting GADD45 beta -- protein, whose name stands for 'Growth Arrest and DNA Damage-inducible' - controls the absorption of fatty acids in the liver.

Mice who lacked the corresponding gene were more likely to develop fatty liver disease.

However when the protein was restored, the fat content of the liver normalised and also sugar metabolism improved.

"The stress on the liver cells caused by fasting consequently appears to stimulate GADD45 beta production, which then adjusts the metabolism to the low food intake," said Stephan Herzig, professor and Director of the Institute for Diabetes and Cancer (IDC) at the Helmholtz Zentrum München in Germany.

Also, in humans, a low GADD45 beta level was accompanied by increased fat accumulation in the liver and an elevated blood sugar level.

"Once we understand how fasting influences our metabolism we can attempt to bring about this effect therapeutically," Herzig added.

The researchers now want to use the new findings for therapeutic intervention in the fat and sugar metabolism so that the positive effects of food deprivation might be translated for treatment.​

New York, May 10 (IANS) Are you getting bored easily when trying to focus, or having difficulty doing quiet tasks and activities? If yes, the pervasive use of a smartphone could be the reason behind these attention-deficit/hyperactivity disorder (ADHD)-like symptoms, new research suggests.

Recent polls have shown that as many as 95 percent of smartphone users have used their phones during social gatherings; that seven in 10 people used their phones while working; and one in 10 admitted to checking their phones during sex. Smartphone owners spend nearly two hours per day using their phones, said lead researcher Kostadin Kushlev from University of Virginia in the US.

"We found the first experimental evidence that smartphone interruptions can cause greater inattention and hyperactivity - symptoms of attention deficit hyperactivity disorder - even in people drawn from a nonclinical population," Kushlev said.

During the study, 221 students at University of British Columbia in Canada drawn from the general student population were assigned for one week to maximise phone interruptions by keeping notification alerts on, and their phones within easy reach. 

During another week participants were assigned to minimise phone interruptions by keeping alerts off and their phones away. 

At the end of each week, participants completed questionnaires assessing inattention and hyperactivity. 

The results showed that the participants experienced significantly higher levels of inattention and hyperactivity when alerts were turned on.

The results suggest that even people who have not been diagnosed with ADHD may experience some of the disorder's symptoms, including distraction, difficulty focusing and getting bored easily when trying to focus, fidgeting, having trouble sitting still, difficulty doing quiet tasks and activities, and restlessness.

"Smartphones may contribute to these symptoms by serving as a quick and easy source of distraction," Kushlev said.

The silver lining is that the problem can be turned off.

The findings were presented at the Association for Computing Machinery's the human-computer interaction conference in San Jose, California.​

​Sydney, May 9 (IANS) Although it may sound counterintuitive, researchers from the University of Adelaide say that the global increase in Type-1 diabetes is directly linked to advances in medical care that has significantly increased the life expectancy of people.

For the study, the researchers looked at the prevalence of Type-1 diabetes in 118 countries and changes in life expectancy from 1950 to 2010.

After applying a measure known as the Biological State Index to the data, they found that the rapid increase in Type-1 diabetes over the last few decades was directly linked with increases in human life expectancy, especially in Western countries.

"Up to the early 20th century, Type-1 diabetes was a horrible and dangerous disease, usually leading to people's death during their teens or early 20s," said lead study author Wenpeng You.

"This meant there was limited opportunity for people with the disease to have children and to pass their genetic material onto future generations. In evolutionary terms, this is what we call 'natural selection',” he explained.

However, with the widespread introduction of insulin from the 1920s onwards, and improvements in modern medicine, life expectancy for people with Type- diabetes has now increased to about 69 years.

"That is a remarkable achievement, but it also means that with reduced natural selection, the genetic material leading to the development of type-1 diabetes may be accumulating at a rapid rate within the world's population," You noted.

The findings were published in the journal BMJ Open Diabetes Research & Care.

The researchers decided to investigate the link because although cases of Type-1 diabetes have been increasing globally, its prevalence is uneven in different parts of the world.

"Not every country has access to good health care, or freely available insulin. In a number of poor countries, such as in Africa, the life expectancy for people with Type-1 diabetes is much lower than in the Western world. This means more people are dying prematurely, with less opportunity to produce offspring who will carry those genes from generation to generation," You said.​

​London, May 10 (IANS) An international team of astrophysicists has detected an intense wind from one of the closest known black holes to the Earth.

The team led by professor Phil Charles from the University of Southampton observed "V404 Cygni" which went into a bright and violent outburst in June 2015 after more than 25 years of quiescence.

They began taking optical measurements of the black hole's accretion disc using the Gran Telescopio CANARIAS (GTC) - the biggest optical-infrared telescope in the world in the Canary Islands.

The results show the presence of a wind of neutral material (unionised hydrogen and helium), which is formed in the outer layers of the accretion disc, regulating the accretion of material by the black hole.

This wind, detected for the first time in a system of this type, has a very high velocity (3,000 kms per second) so that it can escape from the gravitational field around the black hole.

“Its presence allows us to explain why the outburst, in spite of being bright and very violent, with continuous changes in luminosity and ejections of mass in the form of jets, was also very brief, lasting only two weeks,” explained professor Charles.

“V404 Cygni” is a black hole within a binary system located in the constellation of Cygnus. At only 8,000 light years away, it is one of the closest known black holes to the Earth and has a particularly large accretion disc (with a radius of about 10 million kms), making its outbursts especially bright at all wavelengths (X-rays, visible, infrared and radio waves).

The observations also revealed the presence of a nebula formed from material expelled by the wind.

This phenomenon, which has been observed for the first time in a black hole, also allows scientists to estimate the quantity of mass ejected into the interstellar medium.

“This outburst of 'V404 Cygni' will help us understand how black holes swallow material via their accretion discs,” noted Teo Muñoz Darias, researcher at the Instituto de Astrofísica de Canarias (IAC) in a paper published in the journal Nature.​

New York, May 10 (IANS) An experimental malaria vaccine has been found to protect a small number of healthy people from infection for more than one year after immunisation, says a study.

The vaccine, known as the PfSPZ Vaccine, was developed and produced by US-based biotechnology firm Sanaria.

"It is now clear that administering the PfSPZ Vaccine intravenously confers long-term, sterile protection in a small number of participants, which has not been achieved with other current vaccine approaches," said principal investigator of the trial Robert Seder from National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health.

NIAID researchers and collaborators at the University of Maryland School of Medicine in Baltimore conducted the clinical evaluation of the vaccine, which involved immunisation and exposing willing healthy adults to the malaria-causing parasite Plasmodium falciparum (P. falciparum) in a controlled setting.

The parasites that cause malaria are transmitted to humans through the bite of an infected mosquito. 

The PfSPZ Vaccine is composed of live, but weakened P. falciparum sporozoites -- the early developmental form of the parasite.

Previous research showed the PfSPZ Vaccine to be highly protective three weeks after immunisation. In this trial, researchers assessed if protection could last for five months to a year.

For the phase one clinical trial, the researchers enrolled 101 healthy adults aged 18 to 45 years who had never had malaria. 

Of these volunteers, 59 received the vaccine and 32 participants served as controls and were not vaccinated. 

Vaccine recipients were divided into several groups to assess the roles of the route of administration, dose, and number of immunisations in conferring short- and long-term protection against malaria.

To evaluate how well the vaccine prevented malaria infection, all participants - including the control participants who were not vaccinated - were exposed at varying times to the bites of mosquitoes carrying the same P. falciparum strain from which the vaccine was derived. 

The researchers found that the vaccine provided malaria protection for more than one year in 55 percent of people without prior malaria infection. 

The findings were published in the journal Nature Medicine.

In those individuals, the vaccine appeared to confer sterile protection, meaning the individuals would be protected against disease and could not further transmit malaria. 

The vaccinations were also well-tolerated among participants, and there were no serious adverse events attributed to vaccination, said the study.​

Washington, May 10 (IANS) Presence of warm water in the Pacific Ocean due to a stalled El Nino in 2014 stacked the deck for a monstrous version of the warming climate cycle to occur in 2015, a study says.

Easterly winds in the tropical Pacific Ocean stalled a potential El Nino in 2014 and left a swath of warm water in the central Pacific. This left over warm water gave the current El Nino a head start, the researchers explained.

El Nino and La Nina are the warm and cool phases of a recurring climate pattern across the tropical Pacific Ocean called the El Nino-Southern Oscillation, or ENSO. 

The warm and cool phases shift back and forth every two to seven years, and each phase triggers predictable disruptions in temperature, wind, and rain across the globe. 

During El Nino events, water temperatures at the sea surface are higher than normal. Low-level surface winds, which normally blow east to west along the equator, or easterly winds, start blowing the other direction, west to east, or westerly.

In the spring of 2014, strong westerly winds near the equator in the western and central Pacific Ocean created a buzz among scientists - they saw the winds as a sign of a large El Nino event to come in the winter of 2014, said lead author of the study Aaron Levine, a climate scientist at US National Oceanic and Atmospheric Administration (NOAA) Pacific Marine Environmental Laboratory in Seattle, Washington.

But as the summer progressed, El Niño did not form the way scientists expected it to. Sea surface temperatures in the eastern Pacific never warmed enough to truly be called an El Nino, and the buzz fizzled out.

But then, in the spring of 2015, episodes of very strong westerly wind bursts occurred and became more frequent throughout the summer. 

Following a pattern set by previous large El Ninos, 2015 to 2016 became one of the three strongest El Ninos on record, along with 1982 to 1983 and 1997 to 1998, Levine said.

The findings will be published in a forthcoming issue of the journal Geophysical Research Letters.

​Washington, May 10 (IANS) Turning the traditional knowledge on its head that young Earth had a thicker atmosphere, scientists, including an Indian-origin researcher, have found that air at that time exerted at most half the pressure of today's atmosphere.

The new finding reverses the commonly accepted idea that the early Earth had a thicker atmosphere to compensate for weaker sunlight.

The finding also has implications for which gases were in that atmosphere and how biology and climate worked on the early planet.

"For the longest time, people have been thinking the atmospheric pressure might have been higher back then, because the sun was fainter," said lead author Sanjoy Som, who did the work as part of his doctorate in earth and space sciences at University of Washington.

The team used bubbles trapped in 2.7 billion-year-old rocks to reach this conclusion.

"Our result is the opposite of what we were expecting," he added in a paper published in the journal Nature Geoscience.
Som is currently doing astrobiology research at NASA's Ames Research Centre in California.

The idea of using bubbles trapped in cooling lava as a "paleobarometer" to determine the weight of air in our planet's youth occurred decades ago to co-author Roger Buick, professor of earth and space sciences.

A potential site in western Australia was discovered by co-author Tim Blake of University of western Australia.

There, the Beasley River has exposed 2.7 billion-year-old basalt lava.

A stream of molten rock quickly cools from top and bottom, and bubbles trapped at the bottom are smaller than those at the top.

The size difference records the air pressure pushing down on the lava as it cooled, 2.7 billion years ago.

Rough measurements in the field suggested a surprisingly lightweight atmosphere.

More rigorous x-ray scans from several lava flows confirmed the result: The bubbles indicate that the atmospheric pressure at that time was less than half of today's.

Earth 2.7 billion years ago was home only to single-celled microbes, sunlight was about one-fifth weaker and the atmosphere contained no oxygen.

But this finding points to conditions being even more otherworldly than previously thought.

A lighter atmosphere could affect wind strength and other climate patterns and would even alter the boiling point of liquids.

Other geological evidence clearly shows liquid water on Earth at that time so the early atmosphere must have contained more heat-trapping greenhouse gases like methane and carbon dioxide and less nitrogen.

The result also reinforces Buick's 2015 finding that microbes were pulling nitrogen out of Earth's atmosphere some three billion years ago.

"People will need to rewrite the textbooks," the authors noted.

The researchers will now look for other suitable rocks to confirm the findings and learn how atmospheric pressure might have varied through time.​

London, May 10 (IANS) In a finding that could change the way the most common form of stroke is treated globally, researchers have shown that modified dosage of a clot-busting drug can reduce risk of serious bleeding in the brain and improve survival rates.

Intravenous rtPA (or alteplase) is given to people suffering acute ischaemic stroke and works by breaking up clots blocking the flow of blood to the brain.

However, it can cause serious bleeding in the brain in around five per cent of cases, with many of these proving fatal.

Compared to standard dose (0.9mg/kg body weight), the lower dose (0.6mg/kg) of rtPA reduced rates of serious bleeding in the brain, known as intracerebral haemorrhage (ICH), by two thirds, showed the results of the trial of more than 3,000 patients in 100 hospitals worldwide.

"Most patients who have a major stroke want to know they will survive but without being seriously dependent on their family. We have shown this to be the case with the lower dose of the drug,” said one of the researchers Tom Robinson, professor at University of Leicester in Britain.

The findings were published in the New England Journal of Medicine.

"At the moment you could have a stroke but end up dying from a bleed in the brain. It's largely unpredictable as to who will respond and who is at risk with rtPA,” lead author of the study Craig Anderson, professor at Sydney Medical School, University of Sydney in Australia.

"What we have shown is that if we reduce the dose level, we maintain most of the clot busting benefits of the higher dose but with significantly less major bleeds and improved survival rates. On a global scale, this approach could save the lives of many tens of thousands of people,” Anderson noted.​

Washington, May 9 (IANS) In a move that could immensely benefit private space technology companies, NASA has released 56 formerly patented agency technologies into the public domain, making its government-developed technologies freely available for unrestricted commercial use.