Knowledge Update

​New York, July 18 (IANS) The specialised nerve cells in our brain that are responsible for emotional memory also play an important role in fear learning, say researchers.

The team from Mount Sinai Health System in New York City set out to identify the synaptic connections between brain's inhibitory cells called parvalbumin-interneurons (PV-INs), sensory pathways and neighbouring principal neurons in a brain region involved in detecting and responding to dangerous situations.

They found that the sparse but potent population of PV-INs in the amygdala region of the brain influence fear memory encoding -- the process responsible for persistent reactions to trauma-associated cues.

Stimuli encountered during a traumatic event can elicit strong emotional reactions long after the threat has subsided. 

These emotional memories are thought to be encoded through changes in the neural connections or synapses, within the basolateral amygdala that provide outputs to other brain areas, controlling the so-called "fight or flight" response. 

"Our study is the first to show that this default silencing may, in part, be attributable to a sparse population of inhibitory PV-INs," said Roger Clem from Mount Sinai. 

"The complex anatomy of these cells may allow them to function like master regulators on a hair trigger, springing into action to suppress their neighbours when they detect even the slightest sensory perturbation," Clem added.

To investigate whether fear learning alters PV-IN properties and their silencing effect on surrounding neurons, the researchers introduced fear conditioning in a mouse model, pairing an auditory tone with a subsequent aversive foot shock. 

They found that when animals acquire a fear memory, the suppressive influence of PV-INs is relieved, allowing the fear system to respond more vigorously during a "fight-or-flight" response.

The study was published recently in the journal Neuron.​

New York, July 20 (IANS) The key element in our decision-making that serves to both gauging errors and revising our approach is confidence, suggested a new study.

The study, published in the journal Proceedings of the National Academy of Sciences, offers insights into the hierarchical nature of how we make choices over extended periods of time, ranging from medical diagnoses and treatment to the strategies we use to invest our money.

"Overall, we found that the brain uses confidence to gauge errors and revise decision strategy. Specifically, the confidence in our initial assessments influences how we revisit them," said Roozbeh Kiani, Assistant Professor, New York University.

The research was to not only understand simple decisions about information immediately available to us but also to capture decisions about the strategies that guide multiple decisions over time.

"What is challenging about comprehending, why we make certain choices over long periods is to determine the true causes of the outcomes of our decisions," explains Braden Purcell, researcher, New York University.

To do so, the researchers devised an experiment in which subjects judged the net motion direction of multiple dots on a computer screen. The subjects' judgments were recorded by gauging their eye movement toward one of several targets on the screen.

Researchers discovered that when confident about motion direction, subjects attributed negative feedbacks to a change in the environment and quickly explored new targets.

When the subjects were less confident, they counted negative feedbacks as partial evidence for an environment change but withheld exploring a new target until the sum of evidence which is confidence on error trials -- reached a threshold, revealed the study.

According to the researchers, optimal decision-makers should adjust the threshold for switching strategy based on the volatility of the environment -- lower thresholds for environments that change more often.

They tested this possibility and showed that subjects were quicker to explore new targets when changes in the environment happened more frequently

London, July 18 (IANS) Children as young as nine months-old prefer to play with toys specific to their own gender -- boys with cars or balls and girls with dolls or cooking pots, says a new study.

The study, published in the journal of Infant and Child Development, showed that in a familiar nursery environment significant sex differences were evident at an earlier age than gendered identity is usually demonstrated.

“We found that, in general, boys played with male-typed toys more than female-typed toys and girls played with female-typed toys more than male-typed toys,” Brenda Todd, Senior Lecturer in Psychology at City University London.

To investigate the gender preferences seen with toys, the researchers observed the toy preferences of boys and girls engaged in independent play nurseries in Britain, without the presence of a parent. 

The toys used in the study were a doll, a pink teddy bear and a cooking pot for girls, while for boys a car, a blue teddy, a digger and a ball were used.

The 101 boys and girls fell into three age groups: nine to 17 months, when infants can first demonstrate toy preferences in independent play; 18 to 23 months, when critical advances in gender knowledge occur; and 24 to 32 months, when knowledge becomes further established.

Stereotypical toy preferences were found for boys and girls in each of the age groups, demonstrating that sex differences in toy preference appear early in development. 

Both boys and girls showed a trend for an increasing preference with age for toys stereotyped for boys.

"Our results show that there are significant sex differences across all three age groups, with the finding that children in the youngest group, who were aged between nine-17months when infants are able to crawl or walk and therefore make independent selections, being particularly interesting; the ball was a favourite choice for the youngest boys and the youngest girls favoured the cooking pot," Todd noted.

"Sex differences in play and toy choice are of interest in relation to child care, educational practice and developmental theory,” she pointed out.​

New York, July 18 (IANS) Taking a page from Jonathan Swift's "Gulliver's Travels", a team of researchers has created malleable and microscopic self-assembling particles that can serve as the next generation of building blocks in the creation of synthetic materials.

"Our work turns the tiniest of particles from inflexible, Lego-like pieces into ones that can transform themselves into a range of shapes," explained senior author Stefano Sacanna, Assistant Professor at New York University.

"With the ability to change their contours, these particles mimic alterations that occur in nature," Sacanna noted.

The findings appeared in the journal Nature Communications. 

The research focused on engineering particles a micrometer in width --about one/200th the width of a strand of human hair.

Specifically, it aimed to enhance the adaptability of colloids -- small particles suspended within a fluid medium. 

Such everyday items such as paint, milk, gelatin, glass, and porcelain are composed of colloidal dispersions, but it is their potential to control the flow of light that has scientists focused on creating exotic colloidal geometries.

The scientists discovered that -- much like Gulliver tied down by Lilliputians -- metallic particles encased in oil droplets were tethered by many chemical bonds. 

Breaking those tethers via a photocatalytic reaction--in which the absorption of light spurs a chemical response--caused the metallic particle to free itself, producing an overall shape change. 

In other words, shining a light on a simple crystal allowed the scientists to create a material that transforms its microstructure.​

London, July 18 (IANS) Antibodies derived from people suffering from a rare autoimmune disorder may have therapeutic potential for Type 1 diabetes and psoriasis -- a chronic, recurrent inflammatory skin disorder, says a study conduced on mice.

An international team, led by researchers from King's College London, analysed samples taken from 81 people with a rare autoimmune disorder called autoimmune polyendocrine syndrome type 1 (APECED). 

To discover if APECED patients' autoantibodies could have therapeutic potential, the team tested them in a mouse model of psoriasis.

They found that injecting the mice with autoantibodies from the APECED patients could inhibit the development of psoriatic pathology.

The team also found that increased T cell auto-reactivity in patients with APECED was linked with increased B cell auto-reactivity. B cells are a type of immune cell that produce antibodies. 

"This is very significant because antibodies make up one of the largest sectors of the pharmaceutical market, and one of the great quests in the pharmaceutical industry is to be able to routinely generate antibodies against human proteins implicated in diseases," said Adrian Hayday from King's College London. 

"The findings suggest a route to drug recovery in which, naturally arising highly-efficacious autoantibodies can be isolated from patients whose clinical information guides us as to the diseases most likely to benefit from those antibodies," he added in a paper published in the journal Cell.​

New York, July 19 (IANS) Inspired by Vitamin B12, researchers from Harvard University have identified a new class of high-performing organic molecules that can safely store electricity from energy sources like solar and wind power in large batteries.

In their previous work, the team developed a high-capacity flow battery that stored energy in organic molecules called quinones and a food additive called ferrocyanide.

Flow batteries store energy in solutions in external tanks -- the bigger the tanks, the more energy they store.

That advance was a game-changer, delivering the first high-performance, non-flammable, non-toxic, non-corrosive and low-cost chemicals that could enable large-scale, inexpensive electricity storage.

While the versatile quinones show great promise for flow batteries, Harvard researchers continued to explore other organic molecules in pursuit of even better performance.

“Now, after considering about a million different quinones, we have developed a new class of battery electrolyte material that expands the possibilities of what we can do," informed Kaixiang Lin, PhD student at Harvard and first author of the paper.

“Its simple synthesis means it should be manufacturable on a large scale at a very low cost, which is an important goal of this project,” he added in a paper published in the journal Nature Energy.

In this research, the team found inspiration in vitamin B2 which helps store energy from food in the body.

The key difference between B2 and quinones is that nitrogen atoms, instead of oxygen atoms, are involved in picking up and giving off electrons.

"With only a couple of tweaks to the original B2 molecule, this new group of molecules becomes a good candidate for alkaline flow batteries," said Michael J. Aziz from Harvard's John A. Paulson School of Engineering and Applied Sciences (SEAS).

"They have high stability and solubility and provide high battery voltage and storage capacity. Because vitamins are remarkably easy to make, this molecule could be manufactured on a large scale at a very low cost,' Aziz noted.

The team will continue to explore quinones, as well as this new universe of molecules, in pursuit of a high-performing, long-lasting and inexpensive flow battery.​

Sydney, July 19 (IANS) Using seismic data and sophisticated computer simulations, a team of international scientists has revealed the underlying mechanics when a pair of continents part ways -- a phenomenon that is still not completely understood.

The team used computer simulations to uncover a distinct two-phase separation process. 

At first, continents gradually inch apart as a hot, jagged rift is etched into the landscape. 

Then, after millions of years of strained, relentless pulling of the Earth's crust, the continents lurch away from each other, beginning their steady march towards separate sides of the globe as a new ocean forms between them.

According to the study, published in the journal Nature, this work highlights a phenomenon that is otherwise difficult to explain within the conventional framework of plate tectonics.

"Plates tend to shift around quite slowly because they're sitting on an otherwise very viscous mantle," said study co-author Dietmar Muller from the University of Sydney.

"However, throughout Earth's history, there have been plenty of instances where plates have suddenly sped up during supercontinent breakup. This has puzzled us for decades, as this behaviour can't easily be reconciled with our understanding of what drives plate motion," he added.

The study involved analysis of thousands of kilometres of seismic profiles to pinpoint areas where the continents had been vigorously stretched during their detachment. The researchers then designed computer simulations that independently verified this two-phase breakup.

The split did not tend to end amicably. 

"The breakup process leads to margin segmentation, where rapid subsidence, high heat flow and enhanced volcanism characterise the outer margin," said study lead author Sascha Brune from the University of Potsdam, Germany.

It results in a full-margin rupture that sends the outer rims of the continents plunging into the sea.

"The Earth's submerged continental shelves play an indelible role in biogeochemical cycles such as carbon burial and nutrient cycling," Brune said.​

​London, July 19 (IANS) The more variable a brain is and the more its different parts frequently connect with each other, the higher a person's intelligence quotient (IQ) and creativity are, researchers have revealed for the first time.

In a bid to unlock the secrets of the human brain, a team of researchers led by the University of Warwick quantified the brain's dynamic functions, identifying how different parts of the brain interact with each other at different times to discover how the intellect works.

More accurate understanding of human intelligence could lead to future developments in artificial intelligence (AI).

“Advanced brain imaging techniques in our study has helped us gain insights and inform developments in artificial intelligence as well as help establish the basis for understanding and diagnosis of debilitating human mental disorders such as schizophrenia and depression,” explained Professor Jianfeng Feng from the department of computer science studies at Warwick.

Using resting-state MRI analysis on thousands of people's brains around the world, the researchers found that the areas of the brain which are associated with learning and development show high levels of variability, meaning that they change their neural connections with other parts of the brain more frequently, over a matter of minutes or seconds.

On the other hand, regions of the brain which aren't associated with intelligence -- the visual, auditory and sensory-motor areas -- show small variability and adaptability.

Currently, AI systems do not process the variability and adaptability that is vital, as evidenced by Professor Jianfeng's research, to the human brain for growth and learning.

This discovery of dynamic functions inside the brain could be applied to the construction of advanced artificial neural networks for computers, with the ability to learn, grow and adapt.

This study may also have implications for a deeper understanding of another largely misunderstood field: mental health.

Altered patterns of variability were observed in the brain's default network with schizophrenia, autism and Attention Deficit Hyperactivity Disorder (ADHD) patients.

Knowing the root cause of mental health defects brings scientists exponentially closer to treating and preventing them in the future. The paper is forthcoming in the journal Brain.​

​New York, July 19 (IANS) Social networking giant Facebook has announced its support to "App Event Optimisation" across Facebook, Instagram and its Audience Network from Tuesday, promising more installs of apps and actions within the app.