Researchers uncover secrets of miracle fruit

first_img Food peptides activate bitter taste receptors (PhysOrg.com) — Though not very well known in the United States, at least until the past few years, the miracle fruit is a cranberry like fruit that has the unique property of being able to make acidic or bitter foods taste sweet. And while the protein that makes this possible has been known for quite a while, just how exactly it did its trick has been a mystery; until now. A team of Japanese and French researchers working together have solved the puzzle and have published the results of their efforts in the Proceedings of the National Academy of Sciences. Miracle fruit, the berry of the Synsepalum dulcificum plant, grows naturally in West Africa and the locals there have long known of its sweetening properties. Pop one of the little berries in the mouth and for an hour, foods like pickles, beer, grapefruit or lime, taste like sweet versions of their former selves. More recently, the effects of the miracle fruit have been popularized by flavor-tripping parties, so named because of the odd sensational resemblance to the effects of hallucinogens. Or as Keiko Abe, one of the team leads, reports, the effect is rather magical.To get to the bottom of how the miracle fruit performs its magic, the team grew human kidney cells in a dish that were engineered to produce sweet receptor proteins. They then applied a chemical that caused the receptor cells to light up when activated. Next, they applied miraculin, the protein in miracle fruit that is responsible for the sweetening effects. After that they added different substances with different pH levels and found that the miraculin had three distinct impacts on the receptors. At low levels there is little effect, at medium levels the miraculin boosted response and at high levels the receptors were activated on their own.This all happens, the researchers say, because the miraculin protein changes shape when exposed to acids. The higher the level, the more it changes shape. And because the protein binds very strongly to the receptors in the human tongue, those changes in shape change the way the receptors react when acids are introduced into the mouth. The bottom line is, the higher the pH level in a substance, the sweeter it tastes to the person doing the tasting.The end result of this research might be the introduction of a whole new kind of artificial sweetener, either as an ingredient, or as an additive by users wishing only to sweeten ordinary foods. And now that the effects of miraculin are better understood, researchers will next try to see if they can create it from scratch rather than having to rely on Mother Nature to grow it for them. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Photo of Miracle berry (Hamale Lyman/Wikipedia) Citation: Researchers uncover secrets of ‘miracle fruit’ (2011, September 27) retrieved 18 August 2019 from https://phys.org/news/2011-09-uncover-secrets-miracle-fruit.html Explore further More information: Human sweet taste receptor mediates acid-induced sweetness of miraculin, PNAS, Published online before print September 26, 2011, doi: 10.1073/pnas.1016644108AbstractMiraculin (MCL) is a homodimeric protein isolated from the red berries of Richadella dulcifica. MCL, although flat in taste at neutral pH, has taste-modifying activity to convert sour stimuli to sweetness. Once MCL is held on the tongue, strong sweetness is sensed over 1 h each time we taste a sour solution. Nevertheless, no molecular mechanism underlying the taste-modifying activity has been clarified. In this study, we succeeded in quantitatively evaluating the acid-induced sweetness of MCL using a cell-based assay system and found that MCL activated hT1R2-hT1R3 pH-dependently as the pH decreased from 6.5 to 4.8, and that the receptor activation occurred every time an acid solution was applied. Although MCL per se is sensory-inactive at pH 6.7 or higher, it suppressed the response of hT1R2-hT1R3 to other sweeteners at neutral pH and enhanced the response at weakly acidic pH. Using human/mouse chimeric receptors and molecular modeling, we revealed that the amino-terminal domain of hT1R2 is required for the response to MCL. Our data suggest that MCL binds hT1R2-hT1R3 as an antagonist at neutral pH and functionally changes into an agonist at acidic pH, and we conclude this may cause its taste-modifying activity. © 2011 PhysOrg.comlast_img read more

New research suggests tropical cyclones could develop on Saturns largest moon Titan

first_img(Phys.org) —Planetary scientist Tetsuya Tokano of Germany’s University of Cologne has found that the right ingredients might exist on Titan, Saturn’s largest moon, for the formation of tropical cyclones. In his paper published in the journal Icarus, Tokano says that if one the seas on Titan contains enough methane, then all the conditions could be present for the formation of the mini-hurricanes. What caused a giant arrow-shaped cloud on Saturn’s moon Titan? Titan is Saturn’s largest moon and is the only known natural satellite with a dense atmosphere. Its mass is roughly 80 percent larger than that of Earth’s moon, and because of the great distance from the sun, experiences year-round very low temperatures. And while its body is made mostly of a mix of rocks and frozen water, it has an atmosphere that is mostly nitrogen with some ethane and methane. Titan is also the only known moon in the solar system (besides Earth) to have liquid on its surface, and because of that, rainfall. Tokano believes Titan is capable of spawning tropical cyclones because he thinks one or more of the seas on the moon is not only large enough, but has enough methane in it to give rise to the storms—researchers can’t say for sure whether this is the case or not because past observations of the moon have been obscured by the dense atmosphere, making it difficult to determine what lies below.Tropical cyclones are spinning storms that develop on Earth when warm ocean water evaporates into the air, carrying with it enough energy to spawn spinning storms. On Earth, such storms generally develop around the equator, in the tropics, hence their name. On Titan, things would be a lot different as all of the seas that could be capable of generating such storms are located near its North Pole.In studying the topology of Titan, Tokano noted that the moon has at least three seas that should be large enough to support the formation of tropical cyclones, provided there is enough methane in them. He suggests that when methane evaporates up out of a sea during its summer season, it would carry with it heat that would be converted into kinetic energy—enough to drive the formation of a swirling storm. He notes that over the next few years, Titan will be entering its summer season, providing researchers monitoring data from Cassini—the spacecraft orbiting Saturn—an opportunity to see if the distant moon is indeed experiencing any tropical cyclones. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further More information: Tetsuya Tokano, Are tropical cyclones possible over Titan’s polar seas? Icarus, Available online 8 February 2013 dx.doi.org/10.1016/j.icarus.2013.01.023 AbstractWhile extratropical cyclones cannot be expected in Titan’s barotropic troposphere, tropical cyclones which gain their energy from the latent heat of sea evaporation cannot be entirely dismissed over Titan’s polar hydrocarbon seas. The most essential condition for the genesis of tropical cyclones on Titan is a methane-rich composition of the polar seas. The most likely season for Titan’s hypothetical tropical cyclones is around the northern summer solstice when the sea surface gets warmer and the relative vorticity of the near-surface air increases by seasonal convergence and equatorial wave activity. A tropical cyclone would manifest itself as an anti-clockwise swirling vortex right over one of the northern seas (Kraken Mare, Ligeia Mare, Punga Mare) and increase the surface wind over the seas by an order of magnitude. On the other hand, tropical cyclones are unlikely to emerge over Titan’s few tropical lakes for dynamic reasons such as negligible Coriolis parameter and large vertical wind shear.center_img Journal information: Icarus Titan’s hazy orange globe hangs before the Cassini spacecraft. Image credit NASA/JPL/Space Science Institute. Citation: New research suggests tropical cyclones could develop on Saturn’s largest moon Titan (2013, March 21) retrieved 18 August 2019 from https://phys.org/news/2013-03-tropical-cyclones-saturn-largest-moon.html © 2013 Phys.orglast_img read more

Researchers find proof that oysters turn pearls as part of development process

first_img © 2015 Phys.org Citation: Researchers find proof that oysters turn pearls as part of development process (2015, July 15) retrieved 18 August 2019 from https://phys.org/news/2015-07-proof-oysters-pearls.html Credit: NOAA Journal information: Royal Society Open Science This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. For many years researchers and others have speculated on the process that goes on inside of an oyster that results in the formation of a pearl (the only gem produced by an organism), especially the ones that are very nearly perfectly round. Many have suggested that in order for such pearls to come about, it must have been rotated inside the oyster—also markings on many pearls have suggested spinning. But until now, no one has been able to definitively prove that the pearl was turned.Pearls are created in many mollusks, not just oysters, and their development is due to a reaction by the mollusk to an invading bit of material. Because the insides of mollusks are delicate, they need to protect themselves against material that can cause harm—when a bit of sand or silica is detected in the mantel tissue, the mollusk creates a cover for it (called the pearl sac) and adds a material it secretes called nacre (made up mostly of calcium carbonate)—then, according to the researchers, they spin the material to smooth out rough edges.The researchers were able to make this discovery by using a specially modified magnetometer to watch the pearl inside of an oyster as it developed—it allowed for registering magnetic field variations inside the oyster due to magnetic material that was inserted into the pearl center. The setup allowed the researchers to “see” the developing pearl being turned starting after 40 days had passed and continuing on until the pearl was harvested after approximately a year. They report that the pearl was turned at a rate of 1.27° min−1 (averaged over four pearls) and that pearl shape and defects appeared to be impacted when rotating was interrupted.The team also used high magnification techniques to examine patterns that appeared on the surface of pearls during the development process and found that when bumps and grooves appear, the result is irregular notches, whereas those pearls that were more rounded tended to have more precise spiral shapes.center_img (Phys.org)—A team of researchers with members affiliated with institutions in French Polynesia, France and Qatar has finally proved that pearls do spin inside of oysters as they develop. In their paper published in Royal Society Open Science, the team describes their technique and other aspects of peal development they were able to observe. Explore further More information: Yes, it turns: experimental evidence of pearl rotation during its formation, Royal Society Open Science, DOI: 10.1098/rsos.150144AbstractCultured pearls are human creations formed by inserting a nucleus and a small piece of mantle tissue into a living shelled mollusc, usually a pearl oyster. Although many pearl observations intuitively suggest a possible rotation of the nucleated pearl inside the oyster, no experimental demonstration of such a movement has ever been done. This can be explained by the difficulty of observation of such a phenomenon in the tissues of a living animal. To investigate this question of pearl rotation, a magnetometer system was specifically engineered to register magnetic field variations with magnetic sensors from movements of a magnetic nucleus inserted in the pearl oyster. We demonstrated that a continuous movement of the nucleus inside the oyster starts after a minimum of 40 days post-grafting and continues until the pearl harvest. We measured a mean angular speed of 1.27° min−1 calculated for four different oysters. Rotation variability was observed among oysters and may be correlated to pearl shape and defects. Nature’s ability to generate so amazingly complex structures like a pearl has delivered one of its secrets. Pearly perfectionlast_img read more

Irregular fasting can help in weight loss

first_imgAre you obese and worried about your excess weight? Take heart. New research suggests that with irregular fasting and a strictly controlled diet, you can lose more weight and improve your health too. The study showed that women who fasted intermittently as well as restricted their food improved their health more than those who only restricted their diet or only fasted intermittently. Obese women who followed a diet in which they ate 70 per cent of their required energy intake and fasted intermittently lost the most weight. Also Read – Add new books to your shelf”Continuously restricting their diet is the main way that obese women try to tackle their weight,” said lead author Amy Hutchison, from the University of Adelaide in Australia. “This study is adding to evidence that intermittent fasting, at least in the short term, may provide better outcomes than daily continuous diet restriction for health and potentially for weight loss,” added Leonie Heilbronn, Associate Professor at the varsity. By adhering to a strict pattern of intermittent fasting and dieting, obese women have achieved significant weight loss and improvements in their health such as decreased markers for heart disease, said the paper, published in the journal Obesity. For the study, the researchers involved nearly 100 women aged between 35 and 70 who were overweight or obese. They followed a typical Australian diet consisting of 35 per cent fat, 15 per cent protein and 50 per cent carbohydrate over 10 weeks.last_img read more

Moon landing realisation of a dream – Pope

first_img <a href=’http://revive.newsbook.com.mt/www/delivery/ck.php?n=ab2c8853&amp;cb={random}’ target=’_blank’><img src=’https://revive.newsbook.com.mt/www/delivery/avw.php?zoneid=97&amp;cb={random}&amp;n=ab2c8853&amp;ct0={clickurl_enc}’ border=’0′ alt=” /></a> Pope Francis leads the Angelus prayer in Saint Peter’s Square at the Vatican, June 30, 2019. Picture taken June 30, 2019. Vatican Media/­Handout via REUTERSPope Francis leads the Angelus prayer in Saint Peter’s Square at the Vatican, June 30, 2019. Picture taken June 30, 2019. Vatican Media/­Handout via REUTERS “Fifty years ago, yesterday, man set foot on the moon, realizing an extraordinary dream.”Pope Francis made this comment when today Sunday he was making his customary address after the prayer of the Angelus.He prayed that the memory of that  “great step trigger the desire to progress together to even greater goals: more dignity to the weak, more justice between peoples, more future for our common home.”Addressing the crowd gathered in St Peter’s Square for the Angelus prayer, the Pope expressed his hope that the memory of “that great step for humanity” might spark the desire to reach even “greater goals”.Vatican News in one of its reports said that fifty years ago Pope St. Paul VI was one of the millions who watched Neil Armstrong set the first step on the moon. Paul VI was an enthusiast for space travel and spent lots of time at the Vatican Observatory.Service without anxietyPope Francis spoke about today’s Gospel about Martha and Maria. He said that the two sisters welcomed Him, and whilst one sister, Mary, sits at His feet – with the desire to listen to each and every word He speaks – the other sister, Martha, tends to Jesus’ needs.The Pope expressed the importance of Mary’s actions, explaining that when we really listen to Him, the Lord surprises us. The Pope underlined the importance of always making room for the Lord.”Pope Francis also explained Jesus’s words: “Martha, Martha, you are anxious and worried about many things”.Pope Francis explained that with these words, Jesus “does not intend to condemn the attitude of service, but rather the anxiety with which it is sometimes experienced”. Instead, he said “we express Martha’s concern” and we follow her example in order to make sure that in our communities “there is a sense of welcome”, so that “everyone can feel ‘at home’, especially the little ones and the poor”.WhatsApp SharePrintlast_img read more