Knowledge Update

New York, May 23 (IANS) A study into the significance of the plant microbiomes has found the first direct evidence that nitrogen fixation can occur in the branches of trees with no root nodule required.

The study has significant implications for common agricultural crop plants as there is a strongly held belief that only plants with root nodules can benefit from the symbiotic relationship with the nitrogen-fixing bacteria. 

Led by plant microbiologist Sharon Doty from University of Washington, the team demonstrated that poplar trees growing in rocky, inhospitable terrain contain bacteria within them that could provide valuable nutrients to help the plant grow.

The researchers found that microbial communities are highly diverse, varying dramatically even in cuttings next to each other.

"This variability made it especially difficult to quantify the activity but is the key to the biology since it is probably only specific groupings of microorganisms that are working together to provide this nutrient to the host," said Doty.

The microbes the team isolated from wild poplar and willow plants have helped corn, tomatoes and peppers, as well as turf grasses and forest trees to grow with less fertiliser.

"Having access to the key microbial strains that help wild plants thrive on just rocks and sand will be crucial for moving agriculture, bioenergy and forestry away from a dependence on chemical fertilizers and towards a more natural way of boosting plant productivity," Doty noted in a paper published in the journal PLOS ONE.

Nitrogen fixation is a natural process that is essential to sustain all forms of life. 

In naturally occurring low-nutrient environments such as rocky, barren terrain, plants associate with nitrogen-fixing bacteria to acquire this essential nutrient.​

Brasilia, May 23 (IANS) Researchers have developed a biosensor that has been proven capable of detecting molecules that lead to some types of cancer as well as neurodegenerative diseases.

The device is basically a single-layer organic nanometer-scale transistor on a glass slide.

The biosensor contains the reduced form of the peptide glutathione (GSH), which reacts in a specific way when it comes into contact with the enzyme glutathione S-transferase (GST), linked to Parkinson's, Alzheimer's and breast cancer, among other diseases. 

The findings showed that the device could detect such molecules even when they're present at very low levels in the examined material, because of its nanometric sensitivity. 

"This is the first time organic transistor technology has been used in detecting the pair GSH-GST, which is important in diagnosing degenerative diseases,” said Carlos Cesar Bof Bufon from National Nanotechnology Laboratory (LNNano) in Campinas, Brazil.

In addition to being portable and of low cost, the system can also be adapted to detect other substances, such as molecules linked to different diseases and elements present in contaminated material, among other applications. 

This requires replacing the molecules in the sensor with others that react with the chemicals targeted by the test.

The project focuses on the development of point-of-care devices by researchers in a range of knowledge areas, using functional materials to produce simple sensors and microfluidic systems for rapid diagnosis.

"Platforms like this one can be deployed to diagnose complex diseases quickly, safely and relatively cheaply, using nanometer-scale systems to identify molecules of interest in the material analysed," Bufon explained in the paper published in the journal Organic Electronics.

Future works include paper-based biosensors to lower the cost even further and to improve portability and facilitate fabrication as well as disposal, the researchers said.​

​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.​