Knowledge Update

​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.​

​London, July 21 (IANS) Exercise therapy is as effective as surgery for middle-aged patients with a common type of knee injury known as meniscal tear, a study has revealed.

Meniscal tear is the damage to the rubbery discs that cushion the knee joint.

According to the study published in the journal The BMJ, the researchers suggested that supervised exercise therapy be considered a treatment option for middle-aged patients with this type of knee damage.

The research suggests that arthroscopic knee surgery offers little benefit for most patients.

The researchers carried out a randomised controlled trial for the study to compare exercise therapy with arthroscopic surgery among middle-aged patients with degenerative meniscal tears.

They identified 140 affected adults (average age 50 years), almost all of whom had no definitive x-ray evidence of osteoarthritis.

Half of the patients received a supervised exercise programme over 12 weeks (two-three sessions each week) and half received arthroscopic surgery followed by simple daily exercises to perform at home.

Thigh muscle strength was assessed at three months and knee function was recorded at two years.

No clinically relevant difference was found between the two groups for outcomes such as pain, function in sport and recreation, and knee-related quality of life. At three months, muscle strength had improved in the exercise group of patients.

No adverse events occurred in either group during the two-year follow-up. Of all participants in the exercise group, 13 crossed over to surgery during the follow-up period -- with no additional benefits.

"Supervised exercise therapy showed positive effects over surgery in improving thigh muscle strength, at least in short term. Our results should encourage clinicians and middle aged patients with degenerative meniscal tear and no radiographic evidence of osteoarthritis to consider supervised structured exercise therapy as a treatment option," University of Helsinki researcher Teppo Jarvinen said.​

​New Delhi, July 21 (IANS) In its bid to bring best call experience to its over one billion monthly active users, instant messaging platform Whatsapp in its latest Android beta update has added a new call back and voicemail feature, media reported on Thursday.

​New York, July 21 (IANS) With the announcement that one billion people are now using Facebook Messenger every month, the social networking giant's shares hit an all-time intra-day high on Wednesday.

Washington, July 21 (IANS) Using NASA's Hubble Space Telescope, a team of astronomers has conducted the first search for atmospheres around Earth-sized exoplanets beyond our solar system and found indications that increase the chances of presence of life on two rocky exoplanets.

The exoplanets TRAPPIST-1b and TRAPPIST-1c -- approximately 40 light years away -- are unlikely to have puffy, hydrogen-dominated atmospheres usually found on gaseous worlds.

"The lack of a smothering hydrogen-helium envelope increases the chances for habitability on these planets," said team member Nikole Lewis from Space Telescope Science Institute (STScI) in Baltimore. 

"If they had a significant hydrogen-helium envelope, there is no chance that either one of them could potentially support life because the dense atmosphere would act like a greenhouse," he added.

The planets orbit a red dwarf star at least 500 million years old, in the constellation of Aquarius.

TRAPPIST-1b completes a circuit around its red dwarf star in 1.5 days and TRAPPIST-1c in 2.4 days.

The planets are between 20 and 100 times closer to their star than the Earth is to the Sun.

Because their star is so much fainter than our sun, researchers think that at least one of the planets, TRAPPIST-1c, may be within the star's habitable zone, where moderate temperatures could allow for liquid water to pool.

Julien de Wit from the Massachusetts Institute of Technology led a team of scientists to observe the planets in near-infrared light using Hubble's Wide Field Camera 3.

They used spectroscopy to decode the light and reveal clues to the chemical makeup of an atmosphere.

"These initial Hubble observations are a promising first step in learning more about these nearby worlds, whether they could be rocky like the Earth, and whether they could sustain life," said Geoff Yoder, acting associate administrator for NASA's Science Mission Directorate in Washington.

"This is an exciting time for NASA and exoplanet research," he added.

The researchers hope to use Hubble to conduct follow-up observations to search for thinner atmospheres, composed of elements heavier than hydrogen, like those of the Earth and Venus.

"With more data, we could perhaps detect methane or see water features in the atmospheres, which would give us estimates of the depth of the atmospheres," noted Hannah Wakeford from NASA's Goddard Space Flight Centre in a paper appeared in the journal Nature.

Observations from future telescopes, including NASA's James Webb Space Telescope, will help determine the full composition of these atmospheres and hunt for potential bio-signatures.

Webb also will analyse a planet's temperature and surface pressure -- key factors in assessing its habitability.​

Geneva, July 22 (IANS) The World Meteorological Organisation (WMO) on Thursday warned global temperatures for the first six months of this year shattered more records, meaning 2016 is on track to be the world's hottest year on record.

WMO noted June marked the 14th consecutive month of record heat for land and oceans and the 378th consecutive month with temperatures above the 20th century average. The last month with temperatures below the 20th century average was December 1984, Xinhua reported.

"Another month, another record. And another. And another. Decades-long trends of climate change are reaching new climaxes, fuelled by the strong 2015-2016 El Nino," WMO Secretary-General Petteri Taalas was quoted as saying.

"The El Nino event, which turned up the Earth's thermostat, has now disappeared. Climate change, caused by heat-trapping greenhouse gases, will not. This means we face more heatwaves, more extreme rainfall and potential for higher impact tropical cyclones," Taalas added.

Meanwhile, carbon dioxide concentrations have passed the symbolic milestone of 400 parts per million (ppm) in the atmosphere so far this year. Carbon dioxide levels vary according to the season, but the underlying trend is upwards. They showed a surprising increase for the first half of 2016, rising in June 2016 to nearly 407 ppm, four ppm greater than in June 2015.

United Nations Secretary-General Ban Ki-moon has invited leaders to a special event on September 21 to deposit their instruments of ratification, acceptance, approval or accession to the Paris Agreement on climate change. 

It will also provide an opportunity for other countries to publicly commit to the agreement before the end of 2016.