Knowledge Update

London, June 6 (IANS) There could soon be a pill to reduce your calorie consumption as researchers have identified a bitter plant extract that can suppress food intake by stimulating the secretion of gut peptide hormones involved in appetite regulation.

Gut chemosensory mechanisms, particularly those involved in detecting and relaying to the brain the chemical composition of food during digestion, play an important role in regulating appetite and food intake. 

The researchers hypothesised that activation of specific bitter taste receptors which are expressed throughout the gastrointestinal tract by hormone secreting 'enteroendocrine' cells, could also regulate food intake by triggering the release of satiety or 'fullness' hormones, a mechanism termed by the team as the "bitter brake."

The study was conducted by John Ingram and colleagues from the New Zealand Institute for Plant & Food Research Limited and University of Auckland, New Zealand.

The team screened over 900 plant extracts for their ability to stimulate enteroendocrine "I cell" hormone release before identifying a highly bitter, non-nutritive plant derived ingredient they have called "Amarasate extract" to take forward into clinical testing. 

Twenty lean healthy male volunteers were recruited (mean body mass index 23.4 kg/m2) with 19 completing all three treatments within the randomised, double-blind study.

Treatments comprising 500 mg Amarasate extract or a placebo were administered for targeted intestinal (duodenal) or stomach (gastric) release. 

The researchers found that, compared with placebo, both gastric and duodenal delivery of the Amarasate extract stimulated significant increases in the gut peptide hormones CCK, GLP-1 and PYY while significantly reducing total (lunch plus snack) meal energy intake by 218 calories and 226 calories, respectively. 

However, no significant treatment effects were observed for any subjective ratings of appetite or nausea.

"We have demonstrated that activation of the 'bitter brake' mechanism by a bitter plant extract can stimulate the release of gut peptide hormones involved in appetite regulation and suppress subsequent feeding behaviour in healthy men," the authors noted.

The findings were presented at the 2016 European Obesity Summit in Gothenburg, Sweden.​

​Washington, June 3 (IANS) In a discovery that points to exciting geological activity on a distant cold planet billions of miles from the Earth, NASA scientists have discovered that the icy surface of Pluto's "heart" is being constantly renewed by a process called convection that replaces older surface ice with fresher material.

The prime attraction in the photos of Pluto sent by NASA’s New Horizon spacecraft during its July 2015 flyby was its heart -- a large plain informally known as Sputnik Planum.

Combining computer models with topographic and compositional data gathered by the mission last summer, the scientists showed that the surface of Sputnik Planum is covered with icy, churning, convective "cells" 16 to 48 kms across, and less than one million years old. 

The findings offer additional insight into the unusual and highly active geology on Pluto and, perhaps, other bodies like it on the outskirts of the solar system.

"For the first time, we can really determine what these strange welts of the icy surface of Pluto really are," said lead researcher William McKinnon from Washington University in St. Louis. 

"We found evidence that even on a distant cold planet billions of miles from Earth, there is sufficient energy for vigorous geological activity, as long as you have 'the right stuff,' meaning something as soft and pliable as solid nitrogen," noted McKinnon, who is co-investigator on the New Horizons science team.

The study was published in the journal Nature.

McKinnon and colleagues believe the pattern of these cells stems from the slow thermal convection of the nitrogen-dominated ices that fill Sputnik Planum. 

A reservoir that is likely several miles deep in some places, the solid nitrogen is warmed by Pluto's modest internal heat, becomes buoyant and rises up in great blobs -- like a lava lamp -- before cooling off and sinking again to renew the cycle. 

The computer models showed that ice need only be a few miles deep for this process to occur, and that the convection cells are very broad. 

These convective surface motions average only a few centimetres a year - about as fast as your fingernails grow - which means cells recycle their surfaces every 500,000 years or so. While slow on human clocks, it is a fast clip on geological timescales, the researchers said.

"This activity probably helps support Pluto's atmosphere by continually refreshing the surface of 'the heart,'" McKinnon said. 

"It wouldn't surprise us to see this process on other dwarf planets in the Kuiper Belt," he added.

New Horizons flew through the Pluto system on July 14, 2015, making the first close observations of Pluto and its family of five moons.​

Toronto, June 4 (IANS) A dietary supplement containing a blend of 30 vitamins and minerals has the potential to slow the progress of catastrophic neurological diseases such as Alzheimer's and Parkinson's, researchers say.

The supplement has shown remarkable anti-ageing properties that can prevent and even reverse massive brain cell loss, according to the study by Ontario's McMaster University researchers.

"The findings are dramatic," said lead author of the study Jennifer Lemon.

"Our hope is that this supplement could offset some very serious illnesses and ultimately improve quality of life," Lemon noted.

The formula contains common ingredients such as vitamins B, C and D, folic acid, green tea extract, cod liver oil and other nutraceuticals.

The mice used in this study had widespread loss of more than half of their brain cells, severely impacting multiple regions of the brain by one year of age, the human equivalent of severe Alzheimer's disease.

The mice were fed the supplement on small pieces of bagel each day over the course of several months. Over time, researchers found that it completely eliminated the severe brain cell loss and abolished cognitive decline.

"The research suggests that there is tremendous potential with this supplement to help people who are suffering from some catastrophic neurological diseases," Lemon noted.

The findings were published online in the journal Environmental and Molecular Mutagenesis.

"We know this because mice experience the same basic cell mechanisms that contribute to neurodegeneration that humans do. All species, in fact. There is a commonality among us all," she explained.

In addition to looking at the major markers of aging, they also discovered that the mice on the supplements experienced enhancement in vision and most remarkably in the sense of smell - the loss of which is often associated with neurological disease - improved balance and motor activity.

The next step in the research is to test the supplement on humans, likely within the next two years, and target those who are dealing with neurodegenerative diseases, the researchers said.​

​London, June 4 (IANS) What archaeologists earlier thought to be ancient underwater remains of a long lost Greek city were in fact created by a naturally occurring phenomenon, suggests new research.

When underwater divers discovered what looked like paved floors, courtyards and colonnades, they thought they had found the ruins of a long-forgotten civilisation that perished when tidal waves hit the shores of the Greek holiday island Zakynthos.

But new research published in the journal Marine and Petroleum Geology reveals that the site discovered a few years ago was created by a natural geological phenomenon that took place in the Pliocene era - up to five million years ago.

"The site was discovered by snorkelers and first thought to be an ancient city port, lost to the sea. There were what superficially looked like circular column bases, and paved floors. But mysteriously no other signs of life - such as pottery," said lead author Julian Andrews , professor at the University of East Anglia in Norwich, England.

The research team went on to investigate in detail the mineral content and texture of the underwater formation in minute detail, using microscopy, X-ray and stable isotope techniques.

"We investigated the site, which is between two and five meters under water, and found that it is actually a natural geologically occurring phenomenon,” Andrews said.

"The disk and doughnut morphology, which looked a bit like circular column bases, is typical of mineralisation at hydrocarbon seeps - seen both in modern seafloor and palaeo settings,” Andrews noted.

Microbes in the sediment use the carbon in methane as fuel. Microbe-driven oxidation of the methane then changes the chemistry of the sediment forming a kind of natural cement, known to geologists as concretion.

"In this case the cement was an unusual mineral called dolomite which rarely forms in seawater, but can be quite common in microbe-rich sediments,” Andrews explained.​

​Toronto, June 4 (IANS) Factors such as whether you are alone or with friends can affect how wisely you reason, says a study that suggests that our level of wisdom varies depending on the situation.

The study defines wise reasoning as a combination of such abilities as intellectual humility, consideration of others' perspective and looking for compromise. 

"This research does not dismiss that there is a personality component to wisdom, but that's not the whole picture," said lead author of the study Igor Grossmann, Professor at the University of Waterloo in Canada. 

"Situations in daily life affect our personality and ability to reason wisely," Grossmann said.

The observation that wise reasoning varies dramatically across situations in daily life suggests that while it fluctuates, wisdom may not be as rare as we think. 

Further, for different individuals, only certain situations may promote this quality.

"There are many examples where people known for their critical acumen or expertise in ethics seem to fall prey to lack of such acumen or morals. The present findings suggest that those examples are not an anomaly," Grossmann said.

The study was published in the journal Social Psychological and Personality Science.

"We cannot always be at the top of our game in terms of wisdom-related tendencies, and it can be dangerous to generalise based on whether people show wisdom in their personal life or when teaching others in the classroom," Grossmann noted.

By examining conditions and situations under which people may or may not show wisdom in their lives, researchers and practitioners may learn more about situations promoting wisdom in daily life and recreating those situations. 

For the next stage of this work, Grossmann and his team are preparing a tool to assess wisdom according to the situation. ​

London, June 4 (IANS) Researchers have found a new test that can detect changes in the levels of metabolites in the blood and help identify whether a cancer drug is working as designed or not.

According to researchers, cancer drugs affect the amount of metabolites -- the building blocks of fats and proteins -- present in the blood of patients with the deadly disease. 

“Our study is an important step in the development of new precision cancer therapies and is the first to show that blood metabolites have real potential to monitor the effects of novel agents,” said Florence Raynaud from The Institute of Cancer Research in Britain. 

The study investigated the metabolic markers that could accurately assess how cancers were responding to the targeted drug pictilisib.

Pictilisib is designed to specifically target a molecular pathway in cancer cells, called PI3 kinase, which has key a role in cell metabolism and is defective in a range of cancer types.

As cancers with PI3K defects grow, they cause a decrease in the levels of metabolites in the bloodstream.

For the study, published in the journal Molecular Cancer Therapeutics, the team measured the levels of 180 blood markers in 41 patients with advanced cancers in a phase I clinical trial conducted both in preclinical mouse models and also in humans.

In the mice study, the findings showed an increase in the presence of 26 different metabolites in the bloodstream of mice that were given pictilisib, which were low prior to the therapy.

This indicated that the drug was hitting its target as well as reversing the effects of the cancer on mouse metabolites.

In the trial conducted on humans, 22 out of the 26 metabolites increased in response to the pictilisib therapy.

A single dose of pictilisib increased the blood levels of the metabolites, however, when the treatment stopped a resultant decrease was noted, suggesting that the effect was directly related to the introduction of pictilisib.

"Our method could eventually be used to monitor patients routinely during the course of treatment, as a quick and easy way of assessing whether a drug is still working, or whether treatment needs to be adapted," added one of the researchers Paul Workman, Professor at The Institute of Cancer Research.

The new way of monitoring cancer therapy could speed up the development of new-targeted drugs - which exploit specific genetic weaknesses in cancer cells - and help in modifying treatment for patients, the researchers concluded.

​London, June 2 (IANS) A part of the Antarctica coastline has been losing ice to the ocean for over four decades, far longer than had been expected, finds a new study of satellite images.

The images of 2,000 km of west Antarctica's coastline showed a loss of about 1,000 km of ice, the researchers said.

"We knew that ice had been retreating from this region recently but now, thanks to a wealth of freely available satellite data, we know this has been occurring pervasively along the coastline for almost half a century," said lead researcher Frazer Christie, doctoral student at the University of Edinburgh's School of GeoSciences in Britain.

The findings showed that ice has been retreating consistently along almost the entire coastline of Antarctica's Bellingshausen Sea since satellite records began.

Warmer ocean waters reaching Antarctica's coast, rather than rising air temperatures, are the reason behind the loss of ice, the scientists suggest. 

For the study, published in Geophysical Research Letters, the team analysed hundreds of satellite photographs of the ice margin captured by NASA, the United States Geological Survey (USGS) and the European Space Agency (ESA).

The team also monitored ice thickness and thinning rates using data taken from satellites and the air. 

This showed that some of the largest changes, where ice has rapidly thinned and retreated several miles since 1975, correspond to where the ice front is deepest.

"This study provides important context for our understanding of what is causing ice to retreat around the continent," said Robert Bingham from School of GeoSciences. 

The results will help improve estimates of global sea level rise caused by ice melt, the researchers noted adding that further satellite monitoring is needed to track progress of the ice sheet.

"We now know change to West Antarctica has been longstanding, and the challenge ahead is to determine what has been causing these ice losses for so long," Bingham said.​

Washington, June 3 (IANS) In a significant find, astronomers using NASA's Hubble Space Telescope have discovered that the universe is expanding five percent to nine percent faster than expected.

There are a few possible explanations for the universe's excessive speed. One possibility is that dark energy, already known to be accelerating the universe, may be shoving galaxies away from each other with even greater -- or growing -- strength.

"This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 per cent of everything and don't emit light, such as dark energy, dark matter and dark radiation," explained study leader and Nobel Laureate Adam Riess from the Space Telescope Science Institute and Johns Hopkins University.

Riess' team made the discovery by refining the universe's current expansion rate to unprecedented accuracy, reducing the uncertainty to only 2.4 per cent.

For the results, the team looked for galaxies containing both Cepheid stars and Type Ia supernova.

Cepheid stars pulsate at rates that correspond to their true brightness, which can be compared with their apparent brightness as seen from Earth to accurately determine their distance.

Type Ia supernovae are exploding stars that flare with the same brightness and are brilliant enough to be seen from relatively longer distances.

By measuring about 2,400 Cepheid stars in 19 galaxies and comparing the observed brightness of both types of stars, they accurately measured their true brightness and calculated distances to roughly 300 Type Ia supernovae in far-flung galaxies.

The team compared those distances with the expansion of space as measured by the stretching of light from receding galaxies.

They used these two values to calculate how fast the universe expands with time, or the Hubble constant.

The improved Hubble constant value 45.5 miles per second per megaparsec. (A megaparsec equals 3.26 million light-years.)

The new value means the distance between cosmic objects will double in another 9.8 billion years.

Measurements of the afterglow from the Big Bang by NASA's Wilkinson Microwave Anisotropy Probe (WMAP) and the European Space Agency's Planck satellite mission yield predictions which are 5 percent and 9 percent smaller for the Hubble constant, respectively.

"Comparing the universe's expansion rate with WMAP, Planck, and Hubble is like building a bridge," Riess added.

Another possibility of this expansion is that the cosmos contained a new subatomic particle in its early history that travelled close to the speed of light.

Such speedy particles are collectively referred to as "dark radiation" and include previously known particles like neutrinos.

More energy from additional dark radiation could be throwing off the best efforts to predict today's expansion rate from its post-Big Bang trajectory.

The speedier universe may be telling astronomers that Albert Einstein's theory of gravity is incomplete.

"We know so little about the dark parts of the universe, it's important to measure how they push and pull on space over cosmic history," said Lucas Macri from Texas A&M University in College Station.

The results are forthcoming in The Astrophysical Journal.​​

​New York, June 3 (IANS) A team of scientists from Harvard University has co-created a unique "bionic leaf" that uses solar energy to split water molecules and hydrogen-eating bacteria to produce liquid fuels.

Dubbed “bionic leaf 2.0,” the new system can convert solar energy to biomass with 10 percent efficiency -- far above the one per cent seen in the fastest growing plants.

"This is a true artificial photosynthesis system. Before this, people were using artificial photosynthesis for water-splitting but this is a true A-to-Z system and we've gone well over the efficiency of photosynthesis in nature,” said Daniel Nocera, the Patterson Rockwood professor of energy at Harvard University.

While the study shows the system can be used to generate usable fuels, its potential doesn't end there.

"In principle, we have a platform that can make any downstream carbon-based molecule. So this has the potential to be incredibly versatile,” added co-author Pamela Silver, the Elliott T. and Onie H. Adams Professor of Biochemistry and Systems Biology.

For this paper, the team designed a new cobalt-phosphorous alloy catalyst which, “we showed does not make reactive oxygen species. That allowed us to lower the voltage, and that led to a dramatic increase in efficiency”, Nocera noted in a paper published in the journal Science.

The new catalyst also came with another advantage. Its chemical design allows it to "self-heal" -- meaning it wouldn't leech material into solution.

The new system is already effective enough to consider possible commercial applications but within a different model for technology translation.

"It's an important discovery -- it says we can do better than photosynthesis," Nocera said. "But I also want to bring this technology to the developing world as well."

In many ways, the new system marks the fulfillment of the promise of his “artificial leaf” which used solar power to split water and make hydrogen fuel.​

New York, June 3 (IANS) A massive amount of ammonia gas lies beneath the colourful clouds on Jupiter, astronomers have revealed, a discovery coming just a month prior to the arrival of NASA's Juno spacecraft at the planet on July 4.

Using the Karl G. Jansky Very Large Array in New Mexico, the researchers from University of California-Berkeley measured radio emissions from Jupiter's atmosphere in wavelength bands where clouds are transparent. 

The observers were able to see as deep as 100 km below the cloud tops, a largely unexplored region where clouds form.

The planet's thermal radio emissions are partially absorbed by ammonia gas. Based on the amount of absorption, the researchers could determine how much ammonia is present and at what depth.

“We, in essence, created a three-dimensional picture of ammonia gas in Jupiter's atmosphere, which reveals upward and downward motions within the turbulent atmosphere," said principal author Imke de Pater, a UC Berkeley professor of astronomy.

The map bears a striking resemblance to visible-light images taken by amateur astronomers and the Hubble Space Telescope.

The study will shed light on similar processes occuring on other giant planets in our solar system and on newly-discovered giant exoplanets around distant stars.

The radio map shows ammonia-rich gases rising into and forming the upper cloud layers.

Conversely, the radio maps show ammonia-poor air sinking into the planet, similar to how dry air descends from above the cloud layers on Earth.

The map also shows that hotspots -- so-called because they appear bright in radio and thermal infrared images -- are ammonia-poor regions that encircle the planet like a belt just north of the equator. Between these hotspots are ammonia-rich upwellings that bring ammonia from deeper in the planet.

“With radio, we can peer through the clouds and see that those hotspots are interleaved with plumes of ammonia rising from deep in the planet, tracing the vertical undulations of an equatorial wave system," said UC Berkeley research astronomer Michael Wong.

The observations were reported in the journal Science at a time when NASA's Juno spacecraft plans, in part, to measure the amount of water in the deep atmosphere where the Very Large Array looked for ammonia.

"Maps like ours can help put their data into the bigger picture of what's happening in Jupiter's atmosphere," de Pater noted.​