Mine study demonstrates how quickly bacteria can evolve

first_img Citation: Mine study demonstrates how quickly bacteria can evolve (2012, April 30) retrieved 18 August 2019 from https://phys.org/news/2012-04-quickly-bacteria-evolve.html Explore further © 2012 Phys.Org Living sensor can warn of arsenic pollution Journal information: Science (Phys.org) — Two Earth and environmental scientists from the University of California have found that by observing bacteria in situ in an abandoned mine in northern California, they have, as they describe in their paper published in the journal Science, been able to observe how quickly a single nearly undisturbed species of bacteria has evolved in the wild. 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. Vincent Denef and Jillian F. Banfield have been studying the bacterium Leptospirillum that lives on the surface of both still and moving water in the Richmond Mine for over nine years. In so doing, they have found that the bacteria, which they believe initially inhabited the hot dark confines of the original caverns some 50,000 years, has experienced several evolutionary leaps over just the past several decades due to the introduction of bacteria from somewhere outside of the mine. In all, the two have identified six distinct strains of the bacteria, all of which evolved from the single original strain.This has all been made possible by the nearly heroic efforts of the research team, and the harsh conditions of the mine. The Richmond Mine was developed from the caverns that existed in the area also known as the Iron Mountain Mine. As its name implies, excavations in the already existing caverns led to iron mining, which was eventually abandoned in the early sixties, leaving behind one of the most acidic water environments on the planet. Making study even more difficult is the fact that temperatures in the mine hold steady at a scorching 118°F with humidity near 100%.To carry out their study, the two journeyed down into the mine on a periodic basis and collected bacteria samples from several different areas, then brought them back to their lab for DNA analysis. Over time they found they were able to identify six specific strains, each demonstrating an evolutionary leap as outside bacteria mixed with inside bacteria creating a new strain inside that was able to withstand the extreme conditions. But because of those harsh conditions, the researchers assume that many such pairings also likely resulted in new strains that were not able to survive and thus died out. But for those that have been able to survive, the team has found the mine and its bacteria colony to be a nearly ideal research lab; bacteria that exist without the constant need to adapt due to interactions with external environmental organisms.As part of their study, they’ve found that all of the mutations they’ve discovered thus far have occurred in just the past several decades, indicating they may have come about as the result of human activities, but also demonstrating just how quickly bacteria can evolve in an almost pure, yet wild environment.The two next plan to see if they pinpoint the origins of the external bacteria that have led to the evolutionary leaps inside the mine. More information: Science 27 April 2012: Vol. 336 no. 6080 pp. 462-466 DOI: 10.1126/science.1218389last_img read more

ExMIT company rethinks powerfeasting amplifiers

center_img Asymmetric multilevel outphasing (AMO) architecture. Credit: SungWon Chung et al. Citation: Ex-MIT company rethinks power-feasting amplifiers (2012, November 1) retrieved 18 August 2019 from https://phys.org/news/2012-11-ex-mit-company-rethinks-power-feasting-amplifiers.html 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.last_img read more

Researchers develop fully photonicsbased radar system Update

first_img The innovative radar has also been tested in different scenarios. Here the system demonstrator has been moved in a maritime scenario, controlling the naval traffic in the port of Livorno, in collaboration with the local Port Authority. Credit: Antonella Bogoni Journal information: Nature More information: A fully photonics-based coherent radar system, Nature 507, 341–345 (20 March 2014) DOI: 10.1038/nature13078AbstractThe next generation of radar (radio detection and ranging) systems needs to be based on software-defined radio to adapt to variable environments, with higher carrier frequencies for smaller antennas and broadened bandwidth for increased resolution. Today’s digital microwave components (synthesizers and analogue-to-digital converters) suffer from limited bandwidth with high noise at increasing frequencies, so that fully digital radar systems can work up to only a few gigahertz, and noisy analogue up- and downconversions are necessary for higher frequencies. In contrast, photonics provide high precision and ultrawide bandwidth, allowing both the flexible generation of extremely stable radio-frequency signals with arbitrary waveforms up to millimetre waves, and the detection of such signals and their precise direct digitization without downconversion. Until now, the photonics-based generation and detection of radio-frequency signals have been studied separately and have not been tested in a radar system. Here we present the development and the field trial results of a fully photonics-based coherent radar demonstrator carried out within the project PHODIR27. The proposed architecture exploits a single pulsed laser for generating tunable radar signals and receiving their echoes, avoiding radio-frequency up- and downconversion and guaranteeing both the software-defined approach and high resolution. Its performance exceeds state-of-the-art electronics at carrier frequencies above two gigahertz, and the detection of non-cooperating aeroplanes confirms the effectiveness and expected precision of the system. The research team while testing the photonics-based coherent radar system on the roof of the laboratory in Pisa, Italy, detecting the aerial traffic from the close airport. Credit: Antonella Bogoni The radar system the team built is still just a prototype, though it does appear feasible. The team tested its abilities by monitoring real aircraft taking off at a nearby airport and then comparing what they observed with data from traditional electronic signal based systems. They report that the systems matched very closely. That of course is just an initial test, as McKinney notes, much more research and testing will need to be done before the researchers will know if such a system could provide better results than conventional systems. Also, another area of concern is range, which could impact jitter, and thus the accuracy of the system. © 2014 Phys.org 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.center_img A quiet phase: NIST optical tools produce ultra-low-noise microwave signals The radar system, part of a project known as PHODIR (Photonics-based fully digital radar) is an effort to improve the tracking and speed calculation abilities of current electronic signal based systems. It’s well understood that making improvements in such a system will require higher frequency signals, something that can’t be done with current systems due to an increase in noise that creates more uncertainty in the signals received. For that reason, scientists have been looking to use lasers—such signals are much more stable.Building a radar system using a laser requires an optical mode of oscillation that is able to maintain a highly stable phase relationship—that’s the hurdle the researchers had to overcome. They used a mode-locked laser, it allowed for establishing a periodic sequence of laser pulses that exhibited low timing jitter. Using it, in conjunction with a computer running software they wrote, they were able to produce an RF signal with low phase noise by adding an optical filter located past the laser, which was sent to a photo diode, allowing for two optical modes to be selected. (Phys.org) —A team of researchers in Italy has developed the first fully photonics-based coherent radar system. In their paper published in the journal Nature, the team describes how they built their new radar system and what it might mean for the future of radar systems. Jason McKinney of the US Naval Research Laboratory offers a News & Views perspective piece on the development of the radar system in the same issue and outlines issues involved with attempting to implement such a system into real world applications. Citation: Researchers develop fully photonics-based radar system (Update) (2014, March 20) retrieved 18 August 2019 from https://phys.org/news/2014-03-fully-photonics-based-laser.html Explore furtherlast_img read more

Superinsulated clothing could eliminate need for indoor heating

first_img More information: Po-Chun Hsu, et al. “Personal Thermal Management by Metallic Nanowire-Coated Textile.” Nano Letters. DOI: 10.1021/nl5036572 A team of researchers led by Professor Yi Cui, along with PhD student Po-Chun Hsu and others at Stanford University, have published a paper on the AgNW-coated textiles in a recent issue of Nano Letters.As the researchers explain, most strategies to reduce indoor heating focus on improving the insulation of the buildings, such as by using high R-value insulation and low-emissivity windows. However, a large portion of the energy is still wasted on heating empty space and inanimate objects. To avoid this waste, the researchers have used a new strategy called “personal thermal management,” which focuses on heating people. They’ve demonstrated that clothing dipped in a solution of metallic nanowires, such as AgNWs, achieves this goal by both providing passive insulation and allowing for active heating when connected to an external power source.The main advantage of the AgNW-coated clothing is that it reflects over 90% of an individual’s body heat (i.e., infrared radiation) back to the individual. This reflectance is much higher than even the warmest wool sweater, as the average clothing material reflects back only about 20% of body heat. This increase in reflectance is due to differences in the materials’ emissivity, which is a measure of heat radiation. Low-emissivity materials like silver, which has an emissivity of 0.02, emit less radiation and so provide much better insulation than high-emissivity materials like common textiles, which have an emissivity of about 0.8.Of course, wearing clothing made completely of silver would be impractical and uncomfortable, not to mention expensive. A main reason for this discomfort is that silver, like all metals, is not breathable. For example, Mylar blankets, which are made of aluminum and plastic, are extremely warm but are not vapor-permeable, causing moisture to accumulate on a person’s skin. The new AgNW-coated clothing, on the other hand, is breathable due to the nanowires’ porous structure. The large spacing between nanowires of about 300 nm offers plenty of room for water vapor molecules, which are about 0.2 nm, to pass through. The 300-nm spacing is still much too small to allow body heat to pass through, since human body radiation has a wavelength of about 9 µm and so interacts with the nanowire cloth as if it were a continuous metal film, and is reflected. Explore further Clothing coated in AgNWs would feel virtually identical to normal clothing because such a small amount of AgNW solution is required to achieve high reflectivity. Dip-coating cotton cloth into the AgNW solution adds a mass of just 0.1 g/m2, which would be less than 1 gram for an entire outfit. Only a small fraction of this mass is silver, so the cost would be relatively inexpensive. Using other metals such as copper, nickel, or aluminum, which have similar properties as silver, could further reduce costs.Besides providing high levels of passive insulation, AgNW-coated clothing can also provide Joule heating if connected to an electricity source, such as a battery. The researchers demonstrated that as little as 0.9 V can safely raise clothing temperature to 38 °C, which is 1 °C higher than the human body temperature of 37 °C.Variables such as outdoor temperature, length of the winter season, and home size make it difficult to calculate exactly how much energy a person would save by wearing AgNW-coated clothing. However, the researchers have calculated a rough savings estimate of 8.5 kWh of heating energy per person per day, or 1,000 kWh per year assuming that the heating system operates for four months per year. This estimate is based on the average person requiring 367 W of heating power, compared with 12 W required by the AgNW-coating clothing when actively operating. The researchers note that a 1,000 kWh savings in power consumption is equivalent to the power generated by a 2-square-meter solar panel. Plus, fabrication, installation, and maintenance of the solar panel would likely cost much more than the AgNW-coated clothing.When testing the durability of the AgNW-coated clothing, the researchers found that the clothing could withstand multiple wash cycles while maintaining its electrical properties. Surprisingly, the electrical resistance decreased after the first two wash cycles, possibly due to the removal of extra coating on AgNWs and an increase in packing density of the nanowire mesh, and the resistance stabilized after the third wash cycle.The researchers also fabricated and tested clothing coated in a carbon nanotube solution. However, although carbon nanotubes are conductive and therefore suitable for Joule heating, their high emissivity of 0.98 does not enable them to reflect body heat nearly as well as the AgNW coating. 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. © 2015 Phys.org (a) Illustration showing that body heat passes through normal cloth but is reflected by AgNW cloth. (b, c) Photos of AgNW cloth and CNT cloth showing their flexibility. (d, e) SEM images of AgNW cloth and CNT cloth. Credit: Hsu, et al. ©2014 American Chemical Society Journal information: Nano Letters Nanowire clothing could keep people warm—without heating everything else Citation: Super-insulated clothing could eliminate need for indoor heating (2015, January 8) retrieved 18 August 2019 from https://phys.org/news/2015-01-super-insulated-indoor.html (Phys.org)—By wearing clothes that have been dip-coated in a silver nanowire (AgNW) solution that is highly radiation-insulating, a person may stay so warm in the winter that they can greatly reduce or even eliminate their need for heating their home. Considering that 47% of global energy is spent on indoor heating, and 42% of that specifically for residential heating, such highly insulating clothing could potentially have huge cost savings.last_img read more

Scientists make battery electrodes from waste eggshells

first_img The researchers, led by Assistant Professor Da Deng at Wayne State University, have published a paper on the novel approach in a recent issue of the journal Chemistry of Materials.”A large number of eggs are consumed daily, but the disposal of eggshell waste is still a challenging task,” Deng told Phys.org. “We outline an idea of the direct use of waste eggshells (or ‘trash’) as a unique reaction system (or ‘treasure’) for the synthesis of 1D nanorod arrays on eggshell membrane protein fibers. We prepared a composite of crystalline Co9S8 nanorod arrays on carbon fibers that demonstrate promising performance in both lithium- and sodium-ion batteries.”An eggshell has two main parts: the hard shell, which is made mainly of calcium carbonate; and the thin membrane that lines the inside of the hard shell. The membrane is made of protein fibers that contain sulfur and carbon. (The foul odor of rotten eggs is due to the hydrogen sulfide that is released when these sulfide proteins decompose.) In order to recycle eggshells for existing uses, such as fertilizer and dietary supplements, the two parts must be separated using expensive separation processes. One advantage of recycling the eggshells as multifunctional reactors for making battery electrodes is that the two parts do not need to be separated, since both parts are used together.A partially intact hard shell, curved like a small vase, is first placed in a larger container and used to separate two solutions: sodium hydroxide (NaOH) on the outside, and cobalt(II) sulfate (CoSO4) on the inside. If these two solutions were to rapidly come into contact with each other, they would react to form crystalline microparticles of cobalt(II) hydroxide (Co(OH)2). The eggshell keeps the two solutions separated for the most part, but since the shell is semi-permeable, it allows some OH- ions to diffuse very slowly from the outside to the inside of the shell. After about four days, the OH- ions raise the pH of the inside solution from 4.8 to 7, making it less acidic. This provides the right conditions for Co(OH)2 to form in the amorphous form instead of the crystalline form. © 2016 Phys.org Study finds color and thickness of eggshells in wild birds related to light level exposure (a) Photo of the experimental setup using an eggshell as a reactor. (b) Illustration of the reactor system. Credit: Meng et al. ©2016 American Chemical Society Journal information: Chemistry of Materials Explore further The advantage of having Co(OH)2 in the amorphous form is that it forms a coating on pieces of the eggshell membrane inside the shell. The coated membrane is then removed from the solution and heated for about two hours, which leads to both carbonization and sulfurization. The protein fibers are carbonized, meaning they turn into carbon fibers and, in doing so, they release sulfur. The sulfur reacts with the Co(OH)2 to form cobalt sulfide (Co9S8) nanorods. Cobalt sulfide is a commonly used battery electrode material, though not usually in nanorod form.The final product—carbon fibers coated with cobalt sulfide nanorods—can easily be turned into a slurry for use as battery electrodes. The researchers found that the initial battery prototype exhibits a good performance, including maintaining a stable capacity (540 mAh/g) over 300 cycles at low current, though the capacity decreases at higher currents. This cycling rate outperforms that of lithium-ion batteries that use cobalt sulfide films as electrodes. The researchers attribute this improvement to the cobalt sulfide’s nanorod structure. They explain that the nanorods are firmly attached on the carbon fibers, and the carbon fibers enhance contact between the electrode and electrolyte to improve the flow of current.Although this method requires that the eggshells be kept mostly intact, the researchers think that this requirement could be met by eggs prepared in commercial facilities.”Food manufacturers use a large quantity of eggs,” Deng said. “They could provide the eggshells needed. Our technology requires the use of the eggshells in the form of a container, not in the form of pieces of totally smashed eggshells. If the eggs could be broken by an egg cracking machine into containers, it should be possible to preserve the form needed as ‘reactors.’ For example, a half eggshell could still function as a container, but a smaller container as compared to the one we demonstrated in our paper, where we carefully cut a small hole in the eggshell.”Looking forward, cobalt sulfide has many other applications besides as a battery electrode material, such as in supercapacitors, solar cells, and catalysis. Usually, preparing nanostructured cobalt sulfide requires high pressures, toxic and expensive materials, and complex methods. With further refinements, the eggshell method could help alleviate some of these problems. In addition, future research on this method of using eggshells as reactors could lead to the synthesis of other types of nanostructured materials for a variety of uses.”We plan to explore the direct use of the eggshell reactor system to synthesize many other functional materials, which can find applications beyond batteries,” Deng said. Citation: Scientists make battery electrodes from waste eggshells (2016, June 9) retrieved 18 August 2019 from https://phys.org/news/2016-06-scientists-battery-electrodes-eggshells.html More information: Xinghua Meng and Da Deng. “Trash to Treasure: Waste Eggshells Used as Reactor and Template for Synthesis of Co9S8 Nanorod Arrays on Carbon Fibers for Energy Storage.” Chemistry of Materials. DOI: 10.1021/acs.chemmater.6b01142 (Phys.org)—Americans consume 76 billion eggs per year, and while some of the eggshell waste is used for fertilizer or dietary supplements, the majority of these eggshells are thrown away. In a new study, researchers at Wayne State University in Detroit have developed a method to recycle eggshells, using them as “chemical reactors” to synthesize sulfur-containing nanorods that can be used as battery electrodes. 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.last_img read more

A buffet of Ballet

first_imgAll the dance enthuisiasts can head over to experience some great ballet performances as Shriram Bharatiya Kala Kendra is up with their 11th Festival of Ballets that kick started on 9 May. The first day of the festival featured the dance performance Meera. The performance brought up the glory lies in her ability to articulate through her poetry the turbulence that transpired in her life. Meera’s life seems to be an allegory for most women, that centuries later, her name lives on. Wherever she went, through the effervescence of her poetry, she spread the message of liberation and urged an inner awakening. The performance was choreographed by Shashidharan Nair and the music was given by Shubha Mudgal under the production and direction by Shobha Deepak Singh.  Also Read – ‘Playing Jojo was emotionally exhausting’The second day of the festival (10 May) will feature the performance Shree Durga. The performance is choreographed by Shashidharan Nair and the vocal composition is by Shanti Sharma. The performance highlights that Durga and Kali are not vehicles of a bygone era but remain pertinent today. One reads daily about the atrocities on women. When the Gods give boons they themselves become victims of these boons and it is then that they invoke Shree Shakti; feminine power, to vanquish demons in society. Female power conquers over mindless demons of society. Also Read – Leslie doing new comedy special with NetflixOn the third day (15 May), the festival will  present Karna. It is choreographed by Late Guru Krishna Chandra Naik and Shashidharan Nair. The music is given by Barun Gupta. Towards no other persona of the epic of Mahabharata do circumstances remain consistently so hostile. Karna’s life and times are frozen in their entirety and his fortunes into a perpetual predicament. This ballet is dedicated to all the Karnas natural and unnatural, who are denied the rightful place in the social milieu, seen in its correct perspective. Karna’s life has been so unfair that it immediately elicits sympathy. His life in the epic is resplendent with magnificent misadventures and acts of valour. The closing day of the festival (17 May) will be featuring Kumar Sambhava. The music is been given by Barun Gupta and the scripting is done by Neelabh. The act is directed by Shobha Deepak Singh. It is an endearing story of the demon Tarak, who enjoyed sacred protection in the form of a boon of invincibility from Lord Brahma, of which he took blatant advantage and wreaked havoc on earth. In desperation, mankind appealed to Brahma and the gods to save them from Tarak’s oppression and Lord Brahma said that Tarak could only be killed by the son of Lord Shiva and Parvati, with the intervention of Kamdeva, the god of love. Shiva and Parvati married. After a peaceful existence in the mountains, Kartikeya, their eldest son who was incubated in six wombs of celestial virgins, was born to allow the world to rejoice. Kartikeya was taught by Shiva. At the end of his training Shiva asked his son to lead the army into battle and rid the world of Tarak. After a ferocious battle, Kartikeya mustered all his powers and released a deadly bolt against Tarak, that instantly saw him crash to the ground, dead. And so, the darkness lifted from the heavens and earth and the gods and humans rejoiced. Kamdeva’s death and his wife Rati’s lamentation offer the poignant and sad reality of a tale, where good and evil coexist.Where:  Kamani Auditorium, 1 Copernicus MargWhen: 10, 15, 17 May Timing: 7-8.30 pmlast_img read more

In the lap of nature

first_imgA photographer, a writer and an IPS officer, Somesh Goyal has enthralled the audiences across India through his rare collection of photographs. Goyal who has been into photography for the last four decades recently came up with his work Yellowstone: The Artist’s Point at AIFACS that provided a glimpse of the world’s first national park. The show exhibited the pictures taken by him at Yellowstone. Yellowstone is the world’s first national park and one of the largest in the contiguous United States. The park is located at the headwaters of the Yellowstone river, from which it takes its historical name. Home to a remarkable diversity of mammals, birds and fish, it’s one of the world’s foremost wildlife sanctuaries.  Here, every season brings special wonders and each of the park’s varied landscapes offers a range of exciting experiences. The park is home to seven species of conifer trees, more than 1,000 species of native vascular plants, 67 species of mammals and more than 320 bird species!last_img read more

Stressed Help a stranger feel better

first_imgProviding help to friends, acquaintances, and even strangers can reduce the effects of daily stress on our emotions and our mental health, says a study.“Our research shows that when we help others, we can also help ourselves,” explained study author Emily Ansell of the Yale University School of Medicine in the US. “Stressful days usually lead us to have a worse mood and poorer mental health, but our findings suggest that if we do small things for others, such as holding a door open for someone, we won’t feel as poorly on stressful days,” Ansell noted. Also Read – ‘Playing Jojo was emotionally exhausting’In the study, people used their smartphones to report on their feelings and experiences in daily life. A total of 77 adults, ranging from 18 to 44 years old, participated in the 14-day study.The participants received an automated phone reminder every night that prompted them to complete their daily assessment. They were asked to report any stressful life events they experienced that day across several domains such as interpersonal, work/education, home, finance, health/accident, and the total number of events comprised the measure of daily stress.  The results indicated that helping others boosted participants’ daily well-being.  Also Read – Leslie doing new comedy special with NetflixA greater number of helping behaviours was associated with higher levels of daily positive emotion and better overall mental health.“It was surprising how strong and uniform the effects were across daily experiences,” Ansell said. “For example, if a participant did engage in more prosocial behaviours on stressful days, there was essentially no impact of stress on positive emotion or daily mental health. And there was only a slight increase in negative emotion from stress if the participant engaged in more prosocial behaviours,” Ansell pointed out.The study was published in the journal Clinical Psychological Science.last_img read more

Locals distribute food tea to their rescuers

first_imgKolkata: This is a sight which one can behold only in the City of Joy. When the fire-fighters were giving their best to douse the devastating fire at Bagree Market, a group of locals came forward to support them by distributing water, food and tea.It was from almost 3 am on Sunday that the fire-fighters were battling hard to control the fire. They worked under an extremely difficult situation with heavy smoke billowing out of the windows of the building. Additional policemen were also deployed at the spot to ensure that the fire-fighters could work without facing any difficulty. Personnel of the Disaster Management Group were also there to restore normalcy at the earliest. Also Read – Rain batters Kolkata, cripples normal lifeApart from the men in uniform, another set of people were found working relentlessly, distributing food and water among those who were battling the blaze. The firefighting continued for more than 19 hours and the group of people had been working since morning. In a bid to ensure that the rescuers get food, around 500 packets containing pulao were distributed. Again, in the evening, tea was distributed and another 1,000 food packets were distributed after sundown. It may be mentioned that whenever there is any such situation, a good number of people from the city come together to carry out such works. The same thing was witnessed when the Vivekananda Flyover collapsed and the rescue work continued for three to four days. Food and water were distributed so that people working at the spot could get some food as and when required. Some locals from Ekbalpore came to the site where the Majerhat bridge caved-in on September 4 and they were found distributing cakes, biscuits and water among the rescuers.last_img read more

Mediterranean diet helps shed extra kilos

first_imgConsuming a Mediterranean diet rich in vegetable fats such as olive oil or nuts does not lead to significant weight gain compared to a low-fat diet, finds a new research.The findings showed that fats from nuts, fish and phenolic-rich vegetable oils found in the Mediterranean diet are healthier than fats from meat and processed foods. “Our study shows that a Mediterranean diet rich in vegetable fats had little effect on bodyweight or waist circumference compared to people on a low-fat diet,” said lead author Ramon Estruch from the University of Barcelona, Spain. Also Read – ‘Playing Jojo was emotionally exhausting’A Mediterranean diet has been known to reduce mortality, heart diseases as well as cancer.However, the fear of eating an all fat diet means that a low-fat diet continues to be recommended as a means of weight loss, the researchers said. “The study certainly does not imply that unrestricted diets with high levels of unhealthy fats such as butter, processed meat, sweetened beverages, deserts or fast foods are beneficial,” Estruch added. For the study, published in ‘The Lancet Diabetes & Endocrinology’ journal, the team included 7447 participants (men and women) aged 55-80 who were randomly assigned to one of three groups – an unrestricted calorie Mediterranean diet rich in olive oil (2543), an unrestricted calorie Mediterranean diet rich in nuts (2454), or a low-fat diet where the advice was to avoid all dietary fat (2450).  Also Read – Leslie doing new comedy special with NetflixAfter five years, the low-fat diet group (from 40 per cent to 37.4 per cent) showed a decrease in the total fat intake and both Mediterranean diet groups (40 per cent to 41.8 per cent in olive oil; 40.4 per cent to 42.2 per cent in nuts) showed slight increase. The percentage of energy intake from protein and carbohydrate decreased in both Mediterranean diet groups.On an average, participants in all three groups lost some weight with the greatest weight loss seen in the Mediterranean diet with olive oil group (0.88 kg weight reduction in the olive oil group, compared to 0.60 kg for the low-fat diet group and 0.40 kg for the nuts group). “Calorie-obsessed caveats and warnings about healthier, higher-fat choices such as nuts, phenolic-rich vegetable oils, yoghurt should also be dropped. We must abandon the myth that lower-fat, lower-calorie products lead to less weight gain,” commented Dariush Mozaffarian, Professor at Tufts University in the US, in a linked article.last_img read more