Knowledge Update

​London, May 19 (IANS) Taking aspirin immediately after minor strokes could substantially reduce the risk of major strokes in patients who have minor 'warning' events, a team of European researchers has found.

Writing in the journal Lancet, the researchers said that immediate self-treatment with aspirin when patients experience stroke-like symptoms would considerably reduce the risk of major stroke over the next few days.

Aspirin is already given to people who have had a stroke or transient ischaemic attack (TIA -- often called a 'mini-stroke') to prevent further strokes after they have been assessed in hospital and in the longer-term, reducing the subsequent stroke risk by about 15 percent. 

However, based on a previous study, the team suspected that the benefits of more immediate treatment with aspirin could be much greater.

"The risk of a major stroke is very high immediately after a TIA or a minor stroke (about 1,000 times higher than the background rate), but only for a few days,” said lead researcher Peter Rothwell, stroke expert from the University of Oxford.

The team revisited the individual patient data from twelve trials (about 16,000 people) of aspirin for long-term secondary prevention -- that is, to prevent a further stroke -- and data on about 40,000 people from three trials of aspirin in treatment of acute stroke.

They found that almost all of the benefit of aspirin in reducing the risk of another stroke was in the first few weeks, and that aspirin also reduced the severity of these early strokes.

Rather than the 15 percent overall reduction in longer-term risk reported previously in these trials, aspirin reduced the early risk of a fatal or disabling stroke by about 70-80 percent over the first few days and weeks.

"Our findings confirm the effectiveness of urgent treatment after TIA and minor stroke - and show that aspirin is the most important component. Immediate treatment with aspirin can substantially reduce the risk and severity of early recurrent stroke,” Rothwell said.

"This finding has implications for doctors, who should give aspirin immediately if a TIA or minor stroke is suspected, rather than waiting for specialist assessment and investigations,” Rothwell noted.​

Toronto, May 19 (IANS) People with anxiety disorders often refuse or drop out of therapies as it makes them weak and infirm, says a study, suggesting that making mental health treatments easy may be really helpful and beneficial to them.

Anxiety disorders and related problems such as obsessive-compulsive disorder (OCD) are among the most common mental health conditions and although effective therapies for these often debilitating disorders exist, many sufferers find them very difficult to engage with or complete. 

Canadian researchers decided to look for ways to make treatment easier to handle for those who need it most.

The team focused on safety behaviours -- things people do to make themselves feel less anxious.

“Giving patients greater agency is much more effective," said Adam Radomsky from Concordia University in a paper published in the Journal of Anxiety Disorders.

The team followed 157 participants -- ranging from people with low-level anxieties to those diagnosed with OCD -- as they adapted old habits with new ones that they could use to avoid anxiety during exposure therapy.

The therapist exposed the participants to feared objects or situations without any danger.

The findings showed that using new safety behaviours during exposure therapy was slightly more helpful to participants than their usual or typical safety behaviours.

“Under the right conditions, safety behaviours have the potential to make the therapy more effective and more acceptable," added another researcher Hannah Levy.

The findings will help reduce the number of people who refuse or drop out of cognitive behavioural therapies and should result in more people getting the help that they need, the authors noted. ​

Toronto, May 19 (IANS) Parents, please take note! Researchers have found that the more time teenagers spend splitting their attention between various devices such as their phones, video games or TV, the lower their test scores in maths and English tend to be.

More time spent multitasking between different types of media is also associated with greater impulsivity and a poorer working memory in adolescents, said one of the study authors Amy Finn from the University of Toronto. 

The term "media multitasking" describes the act of using multiple media simultaneously, such as having the television on in the background while texting on a smartphone, Finn explained.

While it has been on the rise over the past two decades, especially among adolescents, its influence on cognition, performance at school, and personality has not been assessed before.

For the study the researchers surveyed 73 eighth grade students.

Overall, participants reported consuming a great deal of media, and on average watched 12 hours of television per week. They tended to multitask between mediums 25 percent of the time.

The results show how participants' media consumption patterns outside of school are related to their performance in school tests. 

The researchers found that teenagers who spent more time media multitasking fared significantly worse academically than others. 

They scored lower in certain aspects of their working memory, tended to be more impulsive and were more likely to believe that intelligence is not malleable. 

The study was published in Springer's journal Psychonomic Bulletin & Review.

"We found a link between greater media multitasking and worse academic outcomes in adolescents. This relationship may be due to decreased executive functions and increased impulsiveness - both previously associated with both greater media multitasking and worse academic outcomes," Finn explained.​

​Wellington, May 19 (IANS) To conduct near-space scientific investigations, NASA recently launched a super pressure balloon from Wanaka Airport in New Zealand.

As the balloon travels around the Earth, it may be visible from the ground, particularly at sunrise and sunset, to those who live in the southern hemisphere's mid-latitudes, such as Argentina and South Africa, NASA said in a statement. 

The successful launch of the scientific balloon on Tuesday was the fifth launch attempt for the team. Previous attempts were scrubbed due to weather conditions not conducive for launch.

The purpose of the flight is to test and validate the super pressure balloon technology with the goal of long duration flight at mid-latitudes, NASA said.

The team expects the balloon to be airborne for more than 100 days. The current record for a NASA super pressure balloon flight is 54 days

The science and engineering communities have identified long duration balloon flights at constant altitudes as playing an important role in providing inexpensive access to the near-space environment for science and technology. 

"The balloon is pressurised, healthy, and well on its way for this important test mission,” said Debbie Fairbrother, NASA's balloon program office chief.

NASA estimates the balloon will circumnavigate the globe about the southern hemisphere's mid-latitudes once every one to three weeks, depending on wind speeds in the stratosphere.​

​London, May 19 (IANS) Scientists have found evidence of icy comets orbiting a nearby Sun-like star, which may give a glimpse into how our own solar system developed.

An international team of researchers, led by the University of Cambridge, detected very low levels of carbon monoxide gas around HD 181327, which is located around 160 light years away in the Painter constellation.

The amounts of carbon monoxide detected using data from the Atacama Large Millimetre Array (ALMA) -- an astronomical interferometre of radio telescopes in the Atacama desert of northern Chile -- are consistent with the comets in our own solar system.

The results of the study were presented at the recently-held 'Resolving Planet Formation in the era of ALMA and extreme AO' conference in Santiago, Chile. They have been accepted for publication in the Monthly Notices of the Royal Astronomical Society.

The young star system is about 23 million years old and the study is the first step in establishing the properties of comet clouds around Sun-like stars just after the time of their birth.

"Young systems such as this one are very active, with comets and asteroids slamming into each other and into planets," said led author Sebastian Marino from Cambridge.

"The system has a similar ice composition to our own, so it's a good one to study in order to learn what our solar system looked like early in its existence," Marino added.

Using ALMA, the astronomers observed the star, which is surrounded by a ring of dust caused by the collisions of comets, asteroids and other bodies.

It's likely that this star has planets in orbit around it, but they are impossible to detect using current telescopes.

HD 181327 has a mass about 30 percent greater than the Sun. ​

Geneva, May 19 (IANS) Dramatic gains in life expectancy have been made globally since 2000, but major inequalities persist within and among countries, according to a new report published by World Health Organisation (WHO).

The report, titled "World Health Statistics 2016: Monitoring Health for the SDGs", noted that life expectancy increased by five years between 2000 and 2015 -- the fastest increase since the 1960s, Xinhua news agency reported.

The biggest increase came from WHO African Region, where life expectancy increased by 9.4 years to 60 years, driven mainly by improvements in child survival, malaria control and expanded access to antiretrovirals for treatment of HIV.

"The world has made great strides in reducing the needless suffering and premature deaths that arise from preventable and treatable diseases," said Margaret Chan, Director-General of WHO.

"But the gains have been uneven. Supporting countries to move towards universal health coverage based on strong primary care is the best thing we can do to make sure no-one is left behind," Chan said.

Global life expectancy for children born in 2015 was 71.4 years (73.8 years for females and 69.1 years for males), but an individual child's outlook depends on where he or she is born.

The report showed that newborns in 29 high-income countries have an average life expectancy of 80 years or more, while newborns in 22 countries in sub-Saharan Africa have life expectancy of less than 60 years.

In China, the life expectancy reaches 76.1 years (77.6 years for females and 74.6 years for males).

With an average lifespan of 86.8 years, women in Japan can expect to live the longest. 

Switzerland enjoys the longest average survival for men, at 81.3 years. People in Sierra Leone have the world's lowest life-expectancy for both genders: 50.8 years for women and 49.3 years for men.

​London, May 20 (IANS) Treatments involving long-term use of antibiotics have the potential to disrupt brain functions, suggests a new research which found that healthy gut bacteria is crucial to keeping the mind sharp.

A special kind of immune cell serves as an intermediary between gut bacteria and the brain, showed the findings that could also help to alleviate the symptoms of mental disorders.

The gut and the brain "talk" to one another via hormones, metabolic products or direct neural connections. 

In this study, the researchers switched off the gut microbiome in mice, that is their intestinal bacteria, with a strong concoction of antibiotics. 

Compared to the mice that had not undergone treatment, they subsequently observed significantly fewer newly formed nerve cells in the hippocampus region of the brain. 

The memory of the treated mice also deteriorated because the formation of these new brain cells - a process known as neurogenesis - is important for certain memory functions.

As well as impaired neurogenesis, the researchers also found that the population of a specific immune cell in the brain - the Ly6C(hi) monocytes - decreased significantly when the microbiota was switched off. 

Applied to humans, the findings do not show that all antibiotics disrupt brain function, as the combination of drugs used in the study was extremely potent.

"It is possible, however, that similar effects could result from treatments involving long-term use of antibiotics," said one of the researchers Susanne Wolf from Max Delbruck Centre for Molecular Medicine in the Helmholtz Association, Berlin, Germany.

The findings were published in the journal Cell Reports. 

The research team also found that the antibiotics may affect neurogenesis directly, and not act only via the gut bacteria.

The new study is also of significance for treating people with mental disorders such as schizophrenia or depression, who also have impaired neurogenesis, Wolf said.

"In addition to medication and physical exercise, these patients could potentially also benefit from probiotic preparations,” Wolf noted.​

Toronto, May 20 (IANS) Researchers have discovered a type of brain cells that play a key role in reducing the effects of cocaine on the brain.

The discovery establishes that microglia cells can diminish the adverse changes to neural circuitry brought on by the chronic use of cocaine and has significant implications for developing an effective treatment for addiction.

Microglia may not be as well known as neurons, the brain cells that relay messages, but they have many important functions. 

They constantly monitor their environment, and can act to maintain normal brain functioning.

When they find something amiss, they can produce molecules that instruct neurons to make adaptive changes to their connections. One such example is the inflammatory molecule known as tumor necrosis factor (TNF).

"What we discovered is that cocaine activates these microglia, which causes the release of an inflammatory signal which then tries to reverse the changes that cocaine is inducing in the neurons," said the study's senior author David Stellwagen, associate professor at McGill University in Montreal, Canada.

The study was published in the journal Neuron.

Using a mouse model, the researchers detected this microglia-mediated reversal.

In further experiments the team used a pharmaceutical agent that stimulates microglial production of the inflammatory molecule known as tumour necrosis factor.

The researchers observed that a cocaine-induced behavioural change in mice, the progressive increase in movement induced by cocaine, was reduced in the animals who received this agent.

This exciting result holds promise for one day developing treatments that could cut down on drug relapse rates, which can run as high as 80 percent. 

"If we could develop a treatment that would suppress the craving that addicts have in stressful situations, or when they are re-exposed to situations in which they'd normally be taking the drug, that may allow them to avoid relapse,” Stellwagen said.

"And that's really the therapeutic goal of the work we have been doing," Stellwagen noted.​

New York, May 20 (IANS) Two large meteorites hit the Red Planet millions of years apart, triggering a pair of mega-tsunamis that forever scarred the Martian landscape and yielded evidence of cold, salty oceans conducive to sustaining life, reveal scientists.

About 3.4 billion years ago, a big meteorite impact triggered the first tsunami wave.

“This wave was composed of liquid water. It formed widespread backwash channels to carry the water back to the ocean," said Alberto Fairen, visiting scientist in astronomy at Cornell University.

The scientists found evidence of another big meteorite impact which triggered a second tsunami wave.

In the millions of years between the two meteorite impacts and their associated mega-tsunamis, Mars went through frigid climate change, where water turned to ice.

“The ocean level receded from its original shoreline to form a secondary shoreline, because the climate had become significantly colder,” Fairen added.

The second tsunami formed rounded lobes of ice.

These lobes froze on the land as they reached their maximum extent and the ice never went back to the ocean -- which implies the ocean was at least partially frozen at that time.

“Our paper provides very solid evidence for the existence of very cold oceans on early Mars,” the authors noted.

These icy lobes retained their well-defined boundaries and their flow-related shapes, meaning the frozen ancient ocean was briny.

“Cold, salty waters may offer a refuge for life in extreme environments, as the salts could help keep the water liquid... If life existed on Mars, these icy tsunami lobes are very good candidates to search for biosignatures," Fairen said.

“We have already identified some areas inundated by the tsunamis where the ponded water appears to have emplaced lacustrine sediments, including evaporites," added lead author Alexis Rodriguez of the Planetary Science Institute in Arizona.

“As a follow-up investigation, we plan to characterise these terrains and assess their potential for future robotic or human in-situ exploration,” he noted in Scientific Reports, a publication of the journal Nature.​

New York, May 20 (IANS) The larger the proportion of women on a board of a company, the fewer acquisitions it engages in, says a study.

"We found that this effect existed even if we looked at firms with a single female director on the board," said one of the researchers Craig Crossland from the University of Notre Dame in Indiana, US.

The researchers studied almost 3,000 acquisitions between 1998 and 2010 in the US.

"A change in female board representation from low to high levels was associated with an 18 percent decrease in acquisitiveness, a 12 percent decrease in acquisition size and a reduction of $97.2 million in merger and acquisition spending in a given year," Crossland noted.

In the study, published in the Strategic Management Journal, the researchers noted that increasing the proportion of female directors changes the dynamics of intra-board interactions.

"Groups comprised of distinct categories of people operate differently than groups where everyone shares similar characteristics," Crossland said. 

Diverse groups tend to engage in discussions that are more thorough, more contentious and more likely to identify problems with the topic at hand. 

"We think the boards with higher female representation are more likely to identify these challenges in a given deal, increasing the likelihood that it will be delayed or shelved entirely," Crossland explained. 

Crossland emphasised that the researchers are not making any claims that female directors differ from male directors in terms of dispositional tendencies such as risk-taking propensity or openness to experience​