Knowledge Update

​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​

​New York, May 20 (IANS) If you want your kids to shine in life, better brush up your own technical skills and start using online learning tools and games to help your children perform better, suggests new research.

An American study shows that low-income parents are less likely to use these extra resources or, when they do, they do it less effectively because of differences in motivation and parenting practices.

"A key goal for low-income parents is making sure their children stay in school, so often they are more focused on monitoring whether their kids are doing homework and going to class," said lead study author Betsy DiSalvo from Georgia Institute of Technology in the US. 

"Their attention is directed towards school and not what could happen outside the classroom," DiSalvo added.

The team interviewed 63 parents across socio-economic groups and conducted an online survey of 997 parents. 

The researchers found that higher-income parents are more likely to act as resource providers by searching for opportunities outside of school, whether it be a book, online game or extracurricular activities.

There were also differences between how high-income and lower-income parents use social networks for education. 

The results revealed that when low-income parents turn to online resources they face greater challenges and some of them also seem to experience greater face-saving concerns.

"They had lower perceived technical skills when it came to using computers, portable devices and conducting searches online. Even when they could do it, they downplayed their abilities," DiSalvo explained.

"If we can capture these parents and give them access to these educational resources, we can help them help their children, which can improve their learning for all children,” the authors stated.

The study was presented at Association for Computing Machinery's CHI 2016 conference in San Jose, California.​

​London, May 18 (IANS) Individuals suffering from chronic fatigue tend to be more anxious, distressed and are also more likely to suppress these emotions than people who do not have this condition, says a study.

In addition, when under stress, chronic fatigue syndrome patients show greater activation of the biological "fight or flight" mechanism, which may add to their fatigue, the study said.

"Patients with chronic fatigue syndrome often tell us that stress worsens their symptoms, but this study demonstrates a possible biological mechanism underlying this effect," said lead study author Katharine Rimes from King's College London. 

The findings appeared in the journal Health Psychology.

The research that involved examining 160 people in Britain relied on self and observer reports, as well as physiological responses that were collected before, during or after the participants watched a distressing film clip. 

Half of the participants had been diagnosed with chronic fatigue syndrome while the rest were healthy.

Half of each group were instructed to suppress their emotions and half were told to express their feelings as they wished. 

The researchers measured skin conductance in participants because this increases with greater sweating, which is a sign of activation of the body's sympathetic nervous system. This is often known as the biological fight or flight system used to cope with stress.

Regardless of the instruction they received, the chronic fatigue syndrome participants reported higher anxiety and sadness, and their skin responses indicated they were more distressed than the healthy control group, both before and after the film. 

"These findings may help us understand why some chronic fatigue syndrome patients don't seek out social support at times of stress," Rimes stated.​

​London, May 18 (IANS) Don't pluck that flower at night for the plant might be sleeping after a long day in the sun, suggests new research that measured the changes in the shape of plants during the day and night cycle.

Most living organisms adapt their behaviour to the rhythm of day and night. Plants are no exception: Flowers open in the morning, some tree leaves close during the night. And while researchers have been studying the day and night cycle in plants for a long time, nobody knew whether trees too go to sleep.

To find out, the team of researchers from Austria, Finland and Hungary measured the movement of fully grown trees using laser scanners.

"Our results show that the whole tree droops during night, which can be seen as position change in leaves and branches," said Eetu Puttonen from Finnish Geospatial Research Institute.

"The changes are not too large, only up to 10 cm for trees with a height of about 5 metres, but they were systematic and well within the accuracy of our instruments," Puttonen said.

To rule out effects of weather and location, the experiment was done twice with two different trees. 

The first tree was surveyed in Finland and the other in Austria. 

Both tests were done close to solar equinox, under calm conditions with no wind or condensation. 

The leaves and branches were shown to droop gradually, with the lowest position reached a couple of hours before sunrise. In the morning, the trees returned to their original position within a few hours. 

However, it is not yet clear whether they were "woken up" by the sun or by their own internal rhythm.

The findings appeared in the journal Frontiers in Plant Science.

The researchers noted that laser scanners use infrared light, which is reflected by the leaves. With this scanning technique, a full-sized tree can be automatically mapped within minutes with sub-centimeter resolution.

"We believe that laser scanning point clouds will allow us to develop a deeper understanding of plant sleep patterns and to extend our measurement scope from individual plants to larger areas, like orchards or forest plots," Norbert Pfeifer from Vienna University of Technology in Austria said.​

​Beijing, May 18 (IANS) Chinese scientists have found fossils of the world's oldest known multi-cellular organisms, dating back as far as 1.56 billion years, nearly one billion years earlier than previously estimated.

The research published on Wednesday in the journal "Nature Communications" showed the fossils were found in carbon-rich compressions in China's Hebei province. The biggest was 30 cm long and eight cm wide, Xinhua news agency reported.

Zhu Maoyan, the lead researcher, said the Yanshan Mountain region has Mesoproterozoic sedimentary mudstone. Organic fragments extracted from the host rock show well-preserved multi-cellular cell structures.

Zhu said multi-cellular life with modest diversity existed in the early Mesoproterozoic seas, but the species' affinity to extant species remains unclear.

"Further research will shed light on the ancient marine ecosystem," he said.

Prior to this discovery, fossils of multi-cellular life only dated back some 600 million years.

The new fossils show organisms large enough to be visible to the naked eye and predate the diversification of multi-cellular life by nearly one billion years.​

London, May 19 (IANS) Current rates of climate change could trigger instability in a major Antarctic glacier, ultimately leading to nearly three metre rise of the sea level, say researchers.

The scientists looked at the future of Totten glacier, a significant glacier in Antarctica that drains one of the world's largest areas of ice, on the East Antarctic Ice Sheet (EAIS).

By studying the history of Totten's advances and retreats, the researchers discovered that if climate change continues unabated, the glacier could cross a critical threshold within the next century, entering an irreversible period of very rapid retreat.

This would cause it to withdraw up to 300 kilometres inland in the following centuries and release vast quantities of water, contributing up to 2.9 metres to global sea-level rise.

"The evidence coming together is painting a picture of East Antarctica being much more vulnerable to a warming environment than we thought," said study co-author Martin Siegert, professor at Imperial College London.

"This is something we should worry about. Totten Glacier is losing ice now, and the warm ocean water that is causing this loss has the potential to also push the glacier back to an unstable place," Siegert noted.

The East Antarctic Ice Sheet is currently thought to be relatively stable in the face of global warming compared with the much smaller ice sheet in West Antarctica, but Totten Glacier is bucking the trend by losing substantial amounts of ice. 

The new research revealed that Totten Glacier may be even more vulnerable than previously thought.

The findings were published in the journal Nature. 

To uncover the history of Totten Glacier's movements, the team looked at the sedimentary rocks below the glacier using airborne geophysical surveys. 

From the geological record, influenced by the erosion by ice above, they were able to understand the history of the glacier stretching back millions of years.

The researcehrs found that the glacier has retreated more quickly over certain 'unstable' regions in the past. 

Based on this evidence, the scientists believe that when the glacier hits these regions again we will see the same pattern of rapid retreat.​

​Washington, May 19 (IANS) April 2016 was the 12th consecutive month a monthly global temperature record has been broken, the US government's climate agency said on Wednesday.

"This is the longest such balmy streak in the 137-year record, which dates back to 1880," Xinhua quoted the US National Oceanic and Atmospheric Administration (NOAA) as saying.

"The heat goes on -- and so do the records," the agency added.

For April, the average temperature across global land and ocean surfaces was 1.98 degrees Fahrenheit (1.10 degrees Celsius) above the 20th century average of 56.7 degrees Fahrenheit (13.7 degrees Celsius), according to the monthly report released by the NOAA.

This temperature departure from average was not only the highest for the month of April in the 1880-2016 record, but also the fourth-highest among all months on record, behind March 2016, February 2016, and December 2015, said the report.

On land, all six continents had at least a top nine warm April, with South America, Africa, and Asia observing a record high average temperature for April, the NOAA report said.

Only northeastern Canada and southern South America were cooler than average, with the most notable cool temperature departures across northeastern Canada.

Overall, "April 2016 was characterised by warmer to much warmer-than-average conditions across most of Earth's land surfaces," it concluded.

The globally averaged sea surface temperature for April was also highest for this month on record and surpassed the same period in 1998 by 0.43 degrees Fahrenheit (0.24 degrees Celsius) -- the last time a similar strength El Nino occurred.

This April also saw the the smallest Northern Hemisphere snow cover extent recorded in 50 years of snow-cover data collection.

For the four months of 2016, the average temperature for the globe was 2.05 degrees Fahrenheit (1.14 degrees Celsius) above the 20th-century average of 54.8 degrees Fahrenheit (12.7 degrees Celsius), the report added.​