Knowledge Update

​New York, Sep 21 (IANS) Have you ever wondered how our brain enables us to read a book even in a noisy cafe by filtering out the irrelevant stimuli coming through ears and "gating" in the relevant ones in our vision -- words on a page? It is possible due to the inhibitory neurons that the brain employs in such situations, new research suggests.

The inhibitory neurons are brain's traffic cops that help ensure proper neurological responses to incoming stimuli by suppressing other neurons and working to balance excitatory neurons, which aim to stimulate neuronal activity, said the study.

"Our computational model shows that inhibitory neurons can enable a neural circuit to gate in specific pathways of information while filtering out the rest," said senior author Xiao-Jing Wang, Professor at New York University.

Of particular interest to the team was a specific subtype of inhibitory neurons that targets the excitatory neurons' dendrites -- components of a neuron where inputs from other neurons are located. 

These dendrite-targeting inhibitory neurons are labeled by a biological marker called somatostatin and can be studied selectively by experimentalists. 

The researchers proposed that they not only control the overall inputs to a neuron, but also the inputs from individual pathways -- for example, the visual or auditory pathways converging onto a neuron.

"This was thought to be difficult because the connections from inhibitory neurons to excitatory neurons appeared dense and unstructured," Guangyu Robert Yang, a doctoral candidate in Wang's lab, observed. 

"Thus a surprising finding from our study is that the precision required for pathway-specific gating can be realised by inhibitory neurons," Yang noted.

The study's authors used computational models to show that even with the seemingly random connections, these dendrite-targeting neurons can gate individual pathways by aligning with excitatory inputs. 

In the study published in the journal Nature Communications, they showed that this alignment can be realised through synaptic plasticity -- a brain mechanism for learning through experience.

​New York, Sep 21 (IANS) Rocks formed by the grinding together of other rocks during earthquakes are rich in trapped hydrogen and similar seismic activity on Mars may produce enough hydrogen to support life, a study says.

"Mars is not very seismically active, but our work shows that 'Marsquakes' could produce enough hydrogen to support small populations of microorganisms, at least for short periods of time," said first author of the study Sean McMahon from Yale University, New Haven, Connecticut, US.

"NASA has plans to measure seismic activity on Mars during its 2018 InSight mission, and our data will make those measurements all the more interesting," study co-author John Parnell from University of Aberdeen in Scotland said.

The researchers studied rock formations around active fault lines in the Outer Hebrides, off the coast of Scotland. 

"Previous work has suggested that hydrogen is produced during earthquakes when rocks fracture and grind together. Our measurements suggest that enough hydrogen is produced to support the growth of microorganisms around active faults," McMahon said.

While humans and other animals get their energy mainly from the reaction between oxygen and sugar, bacteria use a wide array of alternative reactions to obtain energy. 

The oxidation of hydrogen gas, for example, generates enough energy for bacteria deep in the Earth's subsurface.

"This is just one part of the emerging picture of the habitability of the Martian subsurface, where other sources of energy for life may also be available. The best way to find evidence of life on Mars may be to examine rocks and minerals that formed deep underground around faults and fractures, which were later brought to the surface by erosion," McMahon pointed out.

The study was published in the journal Astrobiology.

​New York, Sep 21 (IANS) A computer-based brain training programme developed at Yale University helps improve student performance in reading and math -- in some cases even more than individualised tutoring, according to a new study.

In a study of more than 500 second graders, math and reading scores on school- administered tests increased significantly more in children who used the brain training programme Activate during the school year than in control classes.

The effect on math achievement scores was greater than what has been reported for one-on-one tutoring, said the study published in the journal Scientific Reports.

"The programme increases focus, self-control, and memory -- cognitive skills essential for learning," said lead author of the study Bruce Wexler, Professor Emeritus of Psychiatry at Yale University in New Haven, Connecticut, US . 

"And these are the exactly the cognitive skills affected by poverty, so we believe brain training programmes like Activate can help reduce the achievement gaps related to poverty that are seen in schools across the country," Wexler noted.

The findings illustrate that the benefits of the training, conducted three times a week for a four-month period, extend beyond getting better on the training games themselves and lead to improved learning of material that is very different from that in the games.

In a second finding from the same study, researchers discovered that doing a five-minute brain warm-up game just before beginning an Activate math or reading curricular content game can increase math and reading performance. 

New York, Sep 21 (IANS) Exposure to certain common chemicals called endocrine-disrupting chemicals found in several consumer products, including plastic bottles, may reduce levels of vitamin D in the bloodstream, says a study.

Endocrine-disrupting chemicals (EDC) are found in everyday products and throughout the environment. Bisphenol A (BPA), a known EDC, is often found in plastics and other consumer products. 

"Nearly every person on the planet is exposed to BPA and another class of endocrine-disrupting chemicals called phthalates, so the possibility that these chemicals may even slightly reduce vitamin D levels has widespread implications for public health," said the study's first author Lauren Johns from the University of Michigan School of Public Health in Ann Arbor.

EDCs are chemicals or mixtures of chemicals that can cause adverse health effects by interfering with hormones in the body. 

"Vitamin D plays a broad role in maintaining bone and muscle health. In addition, low vitamin D levels have been implicated in outcomes of numerous conditions such as cardiovascular disease, diabetes and cancer," Johns said.

The study examined data from 4,667 US adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2010. 

The participants provided blood samples so their vitamin D levels could be measured. To measure EDC exposure, the participants had their urine analysed for substances left behind after the body metabolised phthalates and BPA.

The study, published in the Journal of Clinical Endocrinology & Metabolism, found people who were exposed to larger amounts of phthalates were more likely to have low levels of vitamin D in the bloodstream than the participants who were exposed to smaller amounts of the EDCs. 

The link was strongest in women. There also was an association between exposure to higher levels of BPA and reduced vitamin D levels in women, although the relationship was not statistically significant in men.

"More research is needed into why an association exists, but it is possible that EDCs alter the active form of vitamin D in the body through some of the same mechanisms that they use to impact similar reproductive and thyroid hormones," senior author of the study John Meeker, Professor at the University of Michigan, explained.

​New York, Sep 20 (IANS) In a bid to build Wi-Fi drones, data servers and virtual reality goggles faster, social media giant Facebook has acquired Silicon Valley-based start-up Nascent Objects for an undisclosed sum, a media report said.

San Francisco, Sep 20 (IANS) Oracle Corp has predicted a sharp drop in the traditional IT spending of businesses across the globe over the next decade, making way for cloud services and leaving more room for innovation than hardware and software maintenance.

​Toronto, Sep 19 (IANS) Excessive use of internet may significantly increase the risk of mental health problems such as depression and anxiety, especially among college-going students, a study has found.

The findings showed that individuals with internet addiction had more trouble dealing with their day-to-day activities, including life at home, at work/school and in social settings.

They had problems with planning and time management, greater levels of attentional impulsivity as well as attention deficit hyperactivity disorder (ADHD).

Internet addiction may also be strongly linked to compulsive behaviour and several other addiction in students, the study said.

"This leads us to a couple of questions like are we grossly underestimating the prevalence of internet addiction and are these other mental health issues a cause or consequence of this excessive reliance on the internet?" said lead researcher Michael Van Ameringen from the McMaster University in Canada.

The study may also have practical medical implications.

"If you are trying to treat someone for an addiction when in fact they are anxious or depressed, then you may be going down the wrong route. We need to understand this more, so we need a bigger sample, drawn from a wider, more varied population," Ameringen added.

The Internet Addiction Test (IAT) developed in 1998 prior to the widespread use of smartphone technology, is the only standard test used to measure excessive reliance on the internet.

However, over the last 18 years internet use has changed radically with a substantial number of people working online, using social media among others, round the clock.

"We were concerned that the IAT questionnaire may not have been picking up on problematic modern internet use, or showing up false positives for people who were simply using the internet rather than being over-reliant on it," Ameringen said.

For the study, the team surveyed 254 students and correlated internet use with general mental health and wellbeing.

Only 33 students met screening criteria for internet addition, according to the IAT.

The research team also administered a further series of self-reported tests to see how the internet addicts compared to the others in the survey on areas such as symptoms of depression and anxiety, impulsiveness, inattention and executive functioning, as well as tests for ADHD.

The results were presented at the European College of Neuropsychopharmacology (ECNP) conference in Vienna, recently.

​New York, Sep 19 (IANS) Refuting claims that it is updating the astrological signs, NASA has said that it did not do it as the space agency studies astronomy not astrology.

"We did not change any Zodiac signs, we just did the math. The Space Place (an educational page for kids run by NASA) article was about how astrology is not astronomy, how it was a relic of ancient history and pointed out the science and math that did come from observations of the night sky," NASA spokesperson Dwayne Brown told Gizmodo.

Last week a news spread that 86 per cent of the people now have a different star sign as NASA had decided to update the astrological signs for the first time in 2,000 years. 

In NASA's educational page for children called Space Place, the agency discussed how, some 3,000 years ago, the ancient Babylonians were keen sky-watchers and thought that the changing positions of constellations throughout the year could be linked to certain behaviours or events on Earth.

As a result of this, those sky-watchers invented the zodiac.

"So, as Earth orbits the Sun, the Sun would appear to pass through each of the 12 parts of the zodiac. Since the Babylonians already had a 12-month calendar (based on the phases of the Moon), each month got a slice of the zodiac all to itself," Science Alert reported on Monday citing the article in Space Place. 

But seeing as this happened 3,000 years ago, things were a bit arbitrary, and for whatever reason, the Babylonians left a constellation out of their zodiac -- Ophiuchus, the report said. 

"Even then, some of the chosen 12 did not fit neatly into their assigned slice of the pie and slopped over into the next one," Space Place noted, adding, "To make a tidy match with their 12-month calendar, the Babylonians ignored the fact that the Sun actually moves through 13 constellations, not 12."

NASA said that due to a tiny wobble in the Earth's axis, the position of those constellations has shifted. This means that those constellations are no longer in the same spots today as they were when the ancient Babylonians were looking up.

But that has nothing to do with change of zodiac signs.

​London, Sep 19 (IANS) Individuals with autism spectrum disorder (ASD) are either over- or under-sensitive to sensory information.

The severity of social difficulties experienced by them daily may increase according to their senstitiveness to touch, which may be more than their visual or auditory sensitivities, a study has found.

The study showed that the sense of touch may play a more crucial role in individuals with ASD than previously assumed. 

For some with ASD, busy and crowded environments such as supermarkets are overwhelming, while others may be less sensitive to pain, or dislike being touched.

They may have difficulties in determining which tactile sensations belong to the action of someone else, the study said.

"The results can yield a novel and crucial link between sensory and social difficulties within the autism spectrum," said Eliane Deschrijver from Ghent University in Belgium.

A normal human brain can detect very quickly when a touch is not their own. However, this process is different in the brain of adults with ASD. 

Their brain may signal to a much lesser extent, when an external touch sensation does not correspond to their own touch.

Individuals who experienced stronger sensory difficulties showed a stronger disturbance in their brain. They were also the ones that experienced more severe social difficulties, the researchers said.

"It is the first time that a relationship could be identified between the way individuals with ASD process tactile information in their brain, and their daily social difficulties," Deschrijver noted.

"These findings can primarily lead to a better understanding of the complex disorder, and of associated difficulties," added Roeljan Wiersema, Professor at Ghent University in Belgium.

In the study, the researchers investigated how the brain of individuals with and without ASD uses own touch to understand touch sensations in the actions of others.

In a series of experiments with electro-encephalography (EEG), the scientists showed that the brain activity of adults with ASD differs from that of adults without ASD while processing touch.

The findings were published online in the journal Social, Cognitive and Affective Neuroscience.