Knowledge Update

​New York, July 22 (IANS) In a bid to use drones to beam free internet to the nearly four billion people (60 per cent of the global population) from the sky, social media giant Facebook has announced the first full-scale test flight of its Aquila solar-powered high-altitude unmanned aircraft.

​Tokyo, July 22 (IANS) Augmented reality smartphone game Pokemon Go finally launched in Japanon Friday, the country of the character's birth and the last big market where the possible release date had generated a huge buzz.

New York, July 22 (IANS) A team of researchers has developed a new type of artificial muscle for soft robotics that can support a broad range of motion at relatively low voltage and no rigid components.

​New York, July 22 (IANS) All high-ranking people do not always turn out to be selfish jerks. Some become generous, especially those who do not feel their status is fair and equitable, a study says.

London, July 21 (IANS) Why do people help those in distress or the needy when there is no direct benefit involved? Why do some people not like bribing or cheating the system? The answer may not lie in genes but elsewhere.

An international team of researchers has found that altruism is favoured by random fluctuations in nature -- offering an explanation to the mystery as to why this seemingly disadvantageous trait has evolved.

The team from the Universities of Bath, Manchester and Princeton (US), developed a mathematical model to predict the path of evolution when altruistic "cooperators" live alongside "cheats" who use up resources but do not themselves contribute.

Humans are not the only organisms to cooperate with one another.

The scientists used the example of Brewer's yeast, which can produce an enzyme called invertase that breaks down complex sugars in the environment, creating more food for all.

However, those that make this enzyme use energy that could instead have been used for reproduction, meaning that a mutant "cheating" strain that waits for others to do the hard work would be able to breed faster as a result.

Darwinian evolution suggests that their ability to breed faster will allow the cheats (and their cheating offspring) to proliferate and eventually take over the whole population.

This problem is common to all altruistic populations, raising the difficult question of how cooperation evolved.

"Scientists have been puzzled by this for a long time. What we are lacking is an explanation of how these behaviours could have evolved in organisms as basic as yeast. Our research proposes a simple answer - it turns out that cooperation is favoured by chance," said Dr Tim Rogers, Royal Society University Research Fellow at University of Bath..

The key insight is that the total size of population that can be supported depends on the proportion of cooperators: more cooperation means more food for all and a larger population.

If, due to chance, there is a random increase in the number of cheats then there is not enough food to go around and total population size will decrease.

Conversely, a random decrease in the number of cheats will allow the population to grow to a larger size, disproportionally benefitting the cooperators.

Dr George Constable, soon to join the University of Bath from Princeton, uses the analogy of flipping a coin, where heads wins ?20 but tails loses ?10.

"Although the odds winning or losing are the same, winning is more good than losing is bad. Random fluctuations in cheat numbers are exploited by the cooperators, who benefit more then they lose out," he noted in a paper appeared in the journal the Proceedings of the National Academy of Sciences.​

​New York, July 21 (IANS) Researchers, including one of Indian-origin, have found that long-term antibiotic treatment in mice decreases levels of amyloid plaques, a hallmark of Alzheimer's disease.

The study, published in the journal Scientific Reports, also showed significant changes in the gut microbiome after antibiotic treatment, suggesting the composition and diversity of bacteria in the gut play an important role in regulating immune system activity that impacts progression of Alzheimer's disease.

"We're exploring very new territory in how the gut influences brain health," said senior author of the study Sangram Sisodia, Professor of Neurosciences at the University of Chicago. 

Two of the key features of Alzheimer's disease are the development of amyloidosis, accumulation of amyloid-beta peptides in the brain, and inflammation of the microglia, brain cells that perform immune system functions in the central nervous system. 

For this study, Sisodia and his team administered high doses of broad-spectrum antibiotics to mice over five to six months. 

At the end of this period, genetic analysis of gut bacteria from the antibiotic-treated mice showed that while the total mass of microbes present was roughly the same as in controls, the diversity of the community changed dramatically. 

The antibiotic-treated mice also showed more than a two-fold decrease in amyloid-beta plaques compared to controls.

While the mechanisms linking these changes is unclear, the study points to the potential in further research on the gut microbiome's influence on the brain and nervous system.

Sisodia cautioned that while the current study opens new possibilities for understanding the role of the gut microbiome in Alzheimer's disease, it iss just a beginning step.

"There's probably not going to be a cure for Alzheimer's disease for several generations, because we know there are changes occurring in the brain and central nervous system 15 to 20 years before clinical onset," he said. 

"We have to find ways to intervene when a patient starts showing clinical signs, and if we learn how changes in gut bacteria affect onset or progression, or how the molecules they produce interact with the nervous system, we could use that to create a new kind of personalized medicine," he noted.​

​New York, July 21 (IANS) A new 3D technique developed by Disney Research can capture the crucial yet subtle details of the eyes with just a single facial scan or even a single photo.

The method requires far less time and hardware than existing eye capture techniques because it employs a parametric model of the eye.

The model can reproduce the variations in the size and shape of the eyeball, the spots, craters and banding of the coloured iris and even the red veins of the white sclera.

"This new method of eye capture enables us to create highly realistic animations for films, games and medical applications and to do so with as little fuss as possible," said Markus Gross, vice president at Disney Research.

The model can be used to automatically duplicate the details of an actor's eyes and can be manipulated to accommodate a story line, such as changing the dilation of the pupils to match lighting conditions, or increasing the size of veins to make the eyes look fatigued.

"After decades of research, facial capture technology is now so advanced that it can be difficult to distinguish between digital faces and real ones," added Thabo Beeler, senior research scientist at Disney Research.

The parametric model is based in large part on a database of 30 eyes that were captured in high resolution using that exhaustive process.

The database provides details about the white sclera and the coloured iris, while a separate model was used to represent variations in the size and shape of the eyeball itself.

The research team will present the findings at the ACM International Conference on Computer Graphics & Interactive Techniques (SIGGRAPH) in California on July 24.​

​London, July 21 (IANS) When it comes to rating one's own abilities, you are strongly influenced by the performance of others, a study has found.

Interaction with high performers makes one feel more capable of being cooperative in team settings but less competent in competitive situations, suggested the study published in the journal Neuron.

The research shows that comparisons with other people can be used as an effective means for self-evaluation and conversely people make judgments about others based on their own traits. 

"We found that although people estimated their abilities on the basis of their own performance in a rational manner, their estimates of themselves were partly merged with the performance of others," University of Oxford researcher Marco Wittmann said.

Moreover, the degree of "self-other-mergence" is associated with an activity in a brain region previously implicated in theory of mind -- the ability to understand the mental state of oneself and others.

Relatively little is known about which brain regions are involved in estimating the abilities of oneself and others, suggested the study.

However, the brain imaging data revealed that two distinct regions in the brains's frontal cortex tracked the estimated abilities of oneself and others.

According to the study, the researchers addressed this question by combining behavioural experiments with functional magnetic resonance imaging. 

Twenty-four subjects participated in two games that involved either assessing the colors of shapes or estimating elapsed time. 

The researchers also assessed how the subjects' expected performance ratings were influenced by cooperative and competitive contexts. 

In cooperative situations, the subjects evaluated themselves more positively when the other players performed well and more negatively when the other players performed poorly. 

However, in the competitive context, the subjects evaluated themselves more negatively when interacted with high performers compared to low performers, the study suggested.

"Our behavioural findings match well with what people experience in their workplace. They might feel better or worse about themselves depending on how well the group they are working with is doing, or they might feel worse about themselves when facing a strong competitor," added Wittman.​

New York, July 21 (IANS) Scientists have developed a new tool to scan the human brain for changes in synapses that are associated with common brain disorders.

A synapse is a junction between two nerve cells, consisting of a minute gap across which impulses pass.

The team from Yale University set out to develop a method for measuring the number of synapses, or synaptic density, in the living brain.

To quantify synapses throughout the brain, they combined Positron Emission Tomography (PET) scanning technology with biochemistry. 

A radioactive tracer was developed that, when injected into the body, binds with a key protein that is present in all synapses across the brain. 

The researchers used the imaging technique in both baboons and humans and confirmed that the new method did serve as a marker for synaptic density. 

It also revealed synaptic loss in three patients with epilepsy compared to healthy individuals.

"This is the first time we have synaptic density measurement in live human beings," said study senior author Richard Carson. 

"Up to now any measurement of synaptic density was post-mortem," he added in a paper published in the journal Science Translational Medicine.

The technique may provide insights into the diagnosis and treatment of a broad range of disorders, including epilepsy and Alzheimer's disease.​