(PhysOrg.com) — Scientists digging in Trowbridge, Wiltshire in England have uncovered the fossilized remains of a prehistoric squid-like creature that lived in the Jurassic period around 150 million years ago. Among their finds was a rock, which they broke open to reveal the intact one-inch long fossilized ink sac. Citation: Scientists Use Squid Ink to Draw its Jurassic Period Owner (2009, August 28) retrieved 18 August 2019 from https://phys.org/news/2009-08-scientists-squid-ink-jurassic-period.html An X-ray Time Machine? The ink sac was found to be similar to modern-day squid ink, and as an experiment, the researchers extracted a sample of the black ink and dissolved the ground specimen in an ammonia solution. To their amazement they were able to use the black, inky solution to write with and even to draw a picture of the animal. The leader of the paleontological dig, Dr Phil Wilby said it is usually only hard parts such as bone and shell that become fossilized, and soft tissue fossils have only been found in a few dozen sites around the world. Dr Wilby explained that sometimes soft-bodied creatures could be turned to stone within a matter of days after death in an effect paleontologists call the Medusa effect, or instantaneous fossilization. The result is a fossil that can be dissected to show even cells and cell nuclei in 3D images when viewed with powerful microscopes. One of the sites where soft tissue fossils had been discovered in the past was in Trowbridge, where thousands of fossils of Jurassic period fossils were found in the 1840s during the construction of the Great Western Railway. Two years ago, Wilby and his team decided to try and find the almost forgotten site. After locating the site through a series of trial drills, they received funding from the Curry Fund and the British Geological Survey, and were able to carry out a ten-day dig to look for fossils.During their excavations the team exposed several thousand fossils of the squid-like creature, Belemnotheutis Antiques, in the 265 tons of rock they examined. Dr Wilby explained that it seems likely the area was a breeding site and the thousands of congregated animals were poisoned by algal blooms. In total the team found a couple of dozen specimens with soft parts such as eyes and muscles perfectly preserved. But the ink sac was the most exciting find.Part of the fossilized ink sac has been sent to a Yale University laboratory in the US for detailed chemical analysis. The rest of the specimen is now in Nottingham in the British Geological Survey collection.More information: Geology Today, Volume 24 Issue 3, Pages 95 – 98. DOI: 10.1111/j.1365-2451.2008.00666.x© 2009 PhysOrg.com Drawing: British Geological Survey (BGS), (c)NERC 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
Citation: Physicists investigate structural properties of spider webs (2010, February 8) retrieved 18 August 2019 from https://phys.org/news/2010-02-physicists-properties-spider-webs.html Spider web glue spins society toward new biobased adhesives Physicists have developed a model for the mechanics of spider orb webs, like the one shown, which spiders have been spinning for at least 200 million years. Credit: Wikimedia Commons. Explore further (PhysOrg.com) — “Although the orb web of a spider is a lightweight structure, it seems to be a highly optimized structure, presumably as a result of evolution from the Jurassic period or earlier,” explain physicists Yuko Aoyananagi and Ko Okumura, who are investigating the structural properties of spider webs. “It seems to resist different loads such as wind and insect impact efficiently and can catch prey even if some threads are broken.” More information: Yuko Aoyanagi and Ko Okumura. “Simple Model for the Mechanics of Spider Webs.” Physical Review Letters 104, 038102 (2010). DOI:10.1103/PhysRevLett.104.038102 Copyright 2010 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Although much research has been done on spider silk as a high-performance fiber, much less is known about the structural mechanical properties of webs. In a recent study, Aoyananagi and Okumura, both from Ochanomizu University in Tokyo, Japan, have developed a model that explains the mechanical adaptability of spider orb webs. As the most familiar web form, orb webs have features that are universal to many spider species, suggesting that they have beneficially evolved by natural selection. By better understanding the unique structural properties of spider webs, researchers could apply the information to other areas, such as designing buildings, bridges, and space structures.As the researchers explain, orb webs consist of two kinds of threads: radial threads radiate out from the center of the web, while spiral threads connect the radial threads together to form the familiar circular pattern. Previous research has shown that the radial threads are significantly stronger than spiral threads, which is due to radial threads’ greater thickness, chemical composition and microscopic structure. When completed by a spider, the entire spider web is under tension. In the physicists’ model, the force distribution is such that the threads with the maximum force are the radial threads located at the outmost parts of the web. The scientists also found that, for a typical web, spiders can change the number of radial or spiral threads without reducing the strength of the web. This versatility is likely very useful for spiders to adapt the web to various environments, such as in areas with few places on which to attach radial threads. Or, when a spider wishes to make the web denser to catch smaller insects, it can spin more spiral threads without significantly increasing the maximum force.Aoyananagi and Okumura also investigated what happens when one of the spiral threads is damaged in an otherwise intact web. In most structures made of elastic materials, the force gets redistributed when damage occurs, and a stress concentration occurs near the damage, which weakens the overall structure. However, in a spider web, the force distribution remains unchanged when any spiral thread is broken, and the web retains its strength. The scientists attribute this damage tolerance to the web’s hierarchical design, which they hope to model in greater detail in the future. 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.
In the study, Liu et al. used dragline silks from the pictured spider species Nephila eduli, Nephila pilipes and Argiope versicolor. Image credit: Spider ID (spiderid.com/pictures/?fwp_attributes=webs) Credit: Science Advances, doi: 10.1126/sciadv.aau9183 Spider silk could be used as robotic muscle , Science Liu et al. then compared the results from the second protocol of cyclic humidity changes in which the spider dragline silk showed torsional response sensitive to humidity, providing a method to control twist deformation. As the number of RH cycles increased, the twist speed and angular acceleration of the dragline silk decreased, indicating that torsional deformation was reaching a state of saturation. The scientists recorded that all silks elongated by approximately 5 to 10 percent after each test. Since humidity-induced twist is a unique characteristic of spider dragline silk, the scientists investigated the molecular structure and the morphology of the material to reveal the underlying mechanism of this behavior. They also analyzed the specific secondary structures and hierarchical structural organization of the molecule. Liu et al. showed that the presence of proline in the MaSp2 protein produced a more pronounced unidirectional twist at the scale of the single molecule. The scientists therefore assumed that the striated linear proline ring orientation may have forced the molecule into a twisted pattern. Using molecular simulation protocols at the protein level, they explained the observed glass transition behavior of spider silk at high RH. Spider silk is a self-assembling biopolymer with hydrogen bonds underlying its chemical structure, yet despite weak chemical bonding it outperforms most materials relative to mechanical performance. The biopolymer is produced from the spider major ampullate gland and is an extraordinary fiber that can surpass most synthetic materials in mechanical toughness by balancing strength and extension/flexibility. Properties of spider dragline silk include high thermal conductivity, peculiar torsion dynamics and the potential for exceptional vibration propagation. To add more distinction to the natural fiber, spider dragline silk display a giant shape-memory effect upon exposure to water; in an effect known as supercontraction. The unique and remarkable properties of spider dragline silk are attributed to its hierarchical structure and morphology. In a recent study, now published in Science Advances, Dabiao Liu and co-workers at the multidisciplinary research fields of engineering, physics, molecular mechanics, biomedical engineering and life sciences, report on the new feature of humidity-induced torsional behavior of spider silk. They demonstrated the impact of spider dragline silk and possible structural origins of the torsional response in the study with potential to engineer a “whole new class of materials”. Understanding the structure-property relationship of spider silk can benefit materials scientists by providing an impression of the precise physical nature of the biopolymer. New biomaterials based on the significant mechanical properties of spider silk can be engineered to translate the structure-property relationship of the material into practical applications. Spider dragline silk material is sensitive to water and can shrink up to fifty percent in length with radial swelling. Water can disrupt hydrogen bonds at high humidity to rearrange the nanocrystalline molecules to lower energetic configurations, resulting in supercontraction. In applied sciences and engineering, supercontraction can find original applications as artificial muscles or tensile actuators. For instance, spider silk from Nephila clavipes and Ornithoctonus huwena can display a reproducible shrink-stretch behavior due to water and humidity, allowing cyclical weight lifting to occur. Recent examples of such applications include engineered torsional artificial muscles with synthetic polymers, carbon nanotubes and graphene-made fibers. Left: SEM images of the fibers and the responses to environmental humidity stimulus. (A) B. mori silk (7.7 ± 0.3 μm in diameter). (B) Human hair (68.7 ± 2.5 μm in diameter). (C) Kevlar fiber (10.7 ± 0.2 μm in diameter). (D) Torsional responses of the representative fibers to environmental humidity: B. mori silk fiber (65.1 mm in length), human hair (69.5 mm in length), and Kevlar fiber (86.9 mm in length). A negligible twist driven by humidity can be seen in these fibers. Right: Torsional actuation of spider dragline silks by increasing the RH from 40 to 100%. (A) Torsional actuation of N. pilipes spider dragline silk (121 mm in length, 3.1 ± 0.1 μm in diameter). (B) Rotation speed (blue line) and angular acceleration (red line) of the torsional actuation of N. pilipes spider dragline silk. (C) Torsional actuation of A. versicolor spider dragline silk (87.9 mm in length, 6.7 ± 0.1 μm in diameter). (D) The rotation speed (blue line) and angular acceleration (red line) of A. versicolor spider dragline silk. Inset shows the SEM images of representative silks. Credit: Science Advances, doi: 10.1126/sciadv.aau9183 In this way, Liu et al. showed that spider dragline silk can generate a huge twist (up to 2550/mm for N. pilipes and 1270/mm for A. versicolor spider dragline silks) under 70 percent RH. The scientists showed that torsional actuation of the material could be controlled simply by tuning the level of the RH. The observed power generated in dragline silk was not passive but an active change of state in response to the driving force of humidity. The humidity-induced twist turned the dragline silk to act as a torsional actuator. These research findings will have applications in the development of humidity-driven soft robots, novel sensors of precise humidity, smart textiles or green energy devices. , Journal of the Royal Society Interface Schematic diagram of the apparatus used to measure torsional actuation of silks or other fibers driven by the relative humidity (RH). Credit: Science Advances, doi: 10.1126/sciadv.aau9183 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. Citation: Spider dragline silk as torsional actuator driven by humidity for applications as artificial muscle (2019, March 7) retrieved 18 August 2019 from https://phys.org/news/2019-03-spider-dragline-silk-torsional-actuator.html Torsional actuation of dragline silks to RH cyclically changing from ~40 to ~100%. (A) N. pilipes dragline silk (98 mm in length, 3.1 ± 0.1 μm in diameter). (B) A. versicolor dragline silk (87.9 mm in length, 6.7 ± 0.1 μm in diameter). (C) N. edulis dragline silk (82 mm in length, 2.8 ± 0.1 μm in diameter). The horizontal dashed lines indicate the RH thresholds to trigger the twist. The vertical dashed lines indicate the start and end of the induced twist. Note that the rotation direction of clockwise direction observed from top to bottom paddle is consistent for all silk samples. Credit: Science Advances, doi: 10.1126/sciadv.aau9183 Using scanning electron microscopy (SEM), the scientists first characterized the morphology and structure of spider silks. They conducted screening tests on three control fibers; B. mori silk, human hair and Kevlar fiber. The experiments revealed the torsional responses of the representative fibers to environmental humidity. They then observed humidity-induced cyclic contractions/relaxations of dragline silk from different spider species to understand torsional actuation driven by humidity in dragline silk. After the tests, the surface of the dragline silk became rougher than at the initial stage. The spider dragline silk of N. pilipes achieved torsional deformation approximating 2550/mm in one direction, a value greater than that generated by carbon nanotube artificial muscles (2500/mm) powered by electricity. The value was also 1000 x greater than those reported for other actuators based on shape-memory alloy and conducting polymers with twist deformation ability. For the A. versicolor dragline silk, the torsional actuation started at 70 percent RH, this value was lower than that of N. pilipes dragline silk but still comparable to carbon nanotube muscles. Although previous studies have investigated torsional properties of spider dragline silk, structural origin of its torsional behavior remains to be explored in depth. In this work, Liu et al. observed the unique behavior of spider dragline silk in comparison to control fibers such as Bombyx mori silk, Kevlar fiber and human hair. The scientists designed the experiments to reveal the stepwise personal response of dragline silk to increased humidity. They conducted atomistic simulations of the two-component proteins MaSp1 and MaSp2 to understand the mechanism of structural twist behavior at the level of the molecule. They then proposed a possible relationship between the observed twist deformation driven by humidity and the molecular structure of dragline silk. Journal information: Science Advances Mechanisms for humidity-induced torsion in dragline silks on a molecular level. (A) Representative angle displacement curve for MaSp2, showing consistent and negative angles traveling down the strands, which corresponds to clockwise twist. Inset shows molecular model of MaSp2. (B) Representative angle displacement curve for MaSp1, showing alternating positive and negative angles. Inset shows molecular model of MaSp1. (C) Hydrogen bond density scaled by the number of those residues present in the MaSp2 sequence. Proline shows the lowest hydrogen bond density compared to other residues. (D) Hydrogen bonds (shown in blue) within a 3-Å radius around (i) glutamine (Gln), (ii) glycine (Gly), and (iii) proline (Pro). (E) Hydrogen bond density scaled by end-to-end molecular length within a 3-Å radius around amino acids Glu, Gly, Ser, Tyr, and all amino acids in sequences MaSp1 and MaSp2. (F) Hydrogen bonds shown in blue in (i) MaSp1 and (ii) MaSp2 molecules. (G) Secondary structure content in MaSp1 and MaSp2. (H) The location of proline residues (with proline rings shown in red) in MaSp2 depicts a striated, linear ring orientation. Zoomed panel shows dotted guiding lines representative of linear proline ring orientation. Credit: Science Advances, doi: 10.1126/sciadv.aau9183 Explore further Liu et al. used dragline silks from Nephila pilipes, Nephila eduli and Argiope versicolor spider species by successfully replicating a previous method for silk sample collection. They used an apparatus based on image processing to study humidity-driven torsional actuation of the thin fibers. In the experimental setup, the scientists used a torsion pendulum made of a single fiber enclosed in a humidity cabinet and recorded the motion of the pendulum using a video camera while increasing or decreasing the relative humidity (RH). They designed two different protocols to understand the response of spider dragline silks to the changing humidity; one protocol increased the RH stepwise to maintain high values for a long period of time. In the second method, they cyclically changed the RH from 40 to 100 percent and returned to 40 percent five times. © 2019 Science X Network More information: Dabiao Liu et al. Spider dragline silk as torsional actuator driven by humidity, Science Advances (2019). DOI: 10.1126/sciadv.aau9183Sinan Keten et al. Nanostructure and molecular mechanics of spider dragline silk protein assemblies, Journal of The Royal Society Interface (2010). DOI: 10.1098/rsif.2010.0149J. Foroughi et al. Torsional Carbon Nanotube Artificial Muscles, Science (2011). DOI: 10.1126/science.1211220
A theatrical adaptation of Mahesh Bhatt’s Hindi classic, Daddy is going to be staged in the Capital soon. Directed by Danish Iqbal, the ninety minute play tells the story of a princess and her father and how her courage broke an evil spell to make them live happily ever after.The show will be graced by the presence of Mahesh Bhatt and Pooja Bhatt among the audience. Imran Zahid has been roped in to reprise the role of the father, played by Anupam Kher on screen. Also Read – ‘Playing Jojo was emotionally exhausting’Mahesh Bhatt says, ‘After the success of Arth’s theatrical version, I thought that Daddy, too ,was a kind of movie that could be brilliantly adapted for the stage. It has same raw human emotions and naked truths about life and hence can have a similar kind of impact. The description of the play is on the shoulders of Danish Iqbal, who is an able director’.Iqbal noted, ‘At a time when, people are moving towards film industry from theatre, it is a good sign that such a renowned director is giving importance to stage’. Also Read – Leslie doing new comedy special with NetflixRajesh Kumar who scripted The Last Salute and Trial of Errors is the script writer for Daddy. Pooja bhatt, who made her big-screen debut with the movie, is excited that the movie is coming alive on stage and a fresh face would be portraying her role. She said, ‘Daddy was my debut film. I had a few offer for commercial movies at that time, and I remember that Bhatt saab had asked me if I’d like to be known as an actor or a star, as he wanted to offer me a film that would be mentioned in my obituary. I’m glad that Daddy touched the lives of many people. The issue is still relevant today and I hope this adaption is going to be a success’.When: 4 – 5 August Where: Sri Ram Centre, Mandi House Time: 7 pm onwards
Kolkata: Mayor Sovan Chatterjee reiterated on Wednesday that the KMC has not waived tax and will not do so for any agency so that the revenue collection of the civic body is not jeopardized by any means.Responding to an allegation from Congress councillor Prakash Upadhyay, who alleged that the KMC is hesitant in mopping up the exorbitant dues of Kolkata Port Trust, Chatterjee at the monthly meeting said: “We will not allow any agency to keep tax dues and will collect it in full amount. The KoPT has already paid us an ad hoc amount of Rs 50 crore. Also Read – Heavy rain hits traffic, flightsPresently, we are trying to obtain the tax due records prior to 2012-13. Some documents in this regard are not tallying with the records of KoPT. We have asked the KoPT to share their records for this time period and will facilitatefurther course of action accordingly.”The Mayor further added that a tripartile meeting in this regard has been held recently with Urban Development minister Firhad Hakim, KMC and KoPTregarding dues.Congress councillor Prakash Upadhyay had demanded an answer from the Mayor regarding what measures have been taken by the civic body to collect tax dues of Rs 422 crore Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedfrom the KoPT.Speaking on the matter, Vinit Kumar, KoPT chairman said: “In a recent meeting with the KMC and state Urban Development andMunicipal Affairs minister, it has been decided that that some settlement will be made concerning the old tax dues. After 2012-13, there were dues of around Rs 150 crore out of which KoPT has already paid Rs 50 crore, three to four months back to the civic body. For the rest of the amount, talks are on.”
The City Sessions Court of Kolkata on Saturday issued an order for arrest warrants against the Gorkha Janmukti Morcha chief Bimal Gurung and 22 others in connection with the alleged murder of Madan Tamang.“We had prayed for the issue of warrant against 23 people accused in the murder of Madan Tamang, including GJM chief Bimal Gurung. The court has ordered to issue the warrant, to be executed by CBI by June 26,” said Arun Bhagat, counsel for CBI.Gorkha leader Madan Tamang was hacked to death at Upper Clubside in the heart of Darjeeling town on May 21, 2010, while overseeing preparations for a public meeting. Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJIMeanwhile, sources in GJM have revealed that the 23 accused are likely to move higher court for anticipatory bail.On May 29, the CBI had filed a charge-sheet against the Morcha chief Gurung, his wife, sitting MLA from Kalimpong, Harkabahadur Chhetry and 20 others in connection with the alleged murder of Tamang, president of Akhil Bharatiya Gorkha League in 2010. Besides Gurung, CBI also filed a charge-sheet against the then office bearers of GJM – assistant general secretary Binoy Tamang, vice-president Pradeep Pradhan, general secretary Roshan Giri and two others Devendra Sharma and Dinesh Theeng have also been named in the charge-sheet.
Kolkata: Once again, residents of Lalgarh are spending sleepless nights being scared that a tiger might have entered the village.The fear has hit the entire village of Lalgarh in Jhargram after one full grown cow and a calf were found critically injured in an attack by an unidentified animal on Saturday morning.The Forest department officials are yet to confirm the animal that had attacked the cow and a calf. A search was conducted by the Forest department officials on Sunday but they have failed to trace the animal. Also Read – Rain batters Kolkata, cripples normal lifeIt may be mentioned that a full grown Royal Bengal tiger was found dead a few months ago in the same area where the incident took place on Saturday.The tiger had strayed into the forests of Lalgarh, from a tiger habitat, hundreds of kilometres away. It was found dead inside the Baghghara forest area in April this year with multiple injury marks on his neck and eyes. The villagers have claimed to have found pug marks at various places in the past few days. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedThe Forest department is yet to confirm whether the footprints found in the Lalgarh forests are of a tiger. Senior forest department officials suspect that they might be of some other animal. A probe has been started in this regard.It was learnt that one Aswini Manna, a resident of Baghghara forest, had taken his four cows and a calf for grazing in the forest on Saturday morning. He left the cows inside the forest and returned home. In the afternoon, three cows returned home, however, the other two did not.Manna went back into the forest only to find his cow and calf serious injured. Several deep injury marks were there on various parts of their bodies. The injuries were caused by sharp claws, suspect the villagers.A senior forest department official in the district said they are looked into matter.Forest personnel have already started a search operation in the area. There is nothing to spread panic, the official said.
Frozen snacks come as a saviour when it comes to pleasing the palate, but quality and safety are some of the things one should keep in mind while purchasing them, says an expert.1. Frozen produce is picked at the peak of its nutrition and flash frozen to maintain the flavours and nutrients. Flash freezing locks in all the product’s goodness. 2. Frozen foods stay fresh for longer because the freezing process suspends enzyme activity that causes the food to rot. Depending on the type of food, you can store it for several months without losing quality, but always check for longevity of your purchase. Also Read – Add new books to your shelf3. Manufacturers have refined preparation, storage and reheating techniques to create flavourful, gourmet-quality meals and entrees. Frozen meals also expose people to foods they might not otherwise eat, such as ethnic foods with long preparation times, or specialty foods that may be too expensive to obtain fresh.4. Freezing suspends microbial and fungal activity in the food. As long as the food remains frozen, it is safe. Frozen ready-to-cook food can be prepared within the hygiene of the house. Add to it your own special touch.
Kolkata: The countdown for the 5th Bengal Global Business Summit 2019 has begun. The two-day business spectacle will be held on February 7 and 8 at the Biswa Bangla Convention Centre, India’s biggest convention centre in New Town.Senior officials including Debashis Sen, NKDA chairman and Alapan Bandyopadhyay, additional chief secretary Industry, along with 100 officials visited the venue and oversaw the last minute arrangements. Chief Minister Mamata Banerjee will host a dinner for the guests at Mistika Banquet at Eco Park. Also Read – Bose & Gandhi: More similar than apart, says Sugata BoseThe officials visited the car parking where final touches are being given. After parking the vehicles, the delegates will have to come to the shuttle point. Buses will be provided to take them to the venue. The main event will be held at the central hall of the convention centre. It will be addressed by the Chief Minister Mamata Banerjee. The state Finance minister Amit Mitra will also address the gathering. The central hall can accommodate 3,000 people. Businessmen from across the country and representatives from various business houses will be present. Cultural shows will be held in the evening. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataThe partner countries are Australia, United Kingdom, Czech Republic, France, Germany, Italy, Japan, Poland, Republic of Korea and UAE. There will be participation from over 35 countries in total. New Town, which is coming up as a Clean and Green city, is ready to welcome the guests. Mamata Banerjee had inaugurated the Biswa Bangla Gate. The roads have been repaired and the railings given a fresh coat of paint. In 2018, business announcements worth Rs 2,19,925 crore were made at the BGBS. There was exchange of business documents, expressions of interest and investment proposals. Around 4,000 delegates from across India and 32 countries took part in the BGBS last year. BGBS started in 2015 and the sole purpose was to give a message to the businessmen that Bengal now is an ideal destination for invest- ment. During 34 years of the Left Front regime, strikes and bandhs made businessmen feel insecure to invest in Bengal. Under the Trinamool Congress rule, the situation has improved vastly, with the investors showing keen interest to invest in the state. A 22-member French delegation to be led by its Ambassador to India will participate in the summit. Ambassador of France to India, Alexandre Ziegler, Minister Counsellor and head of the regional economic department of the Embassy of France in India Jean-Marc Fenet and Consul General of France in Kolkata Virginie Corteval, will be leading a 22 member French business delegation comprising 14 French companies for BGBS, Embassy officials said. Accor, Alstom, Bassetti, Capgemini, Decathlon and Schneider Electric would participate in the summit. It may be mentioned that more than 600 French companies operate in India.
In the midst of today’s hectic lifestyle, let’s spare a thought for one of the biggest threats to our health and general well-being: Excess of processed high calories and sugar. It is said that “prevention is better than cure”. Does this mean we should stop consuming food and drinks which have sugar? Maybe not. What if someone told you that you can maintain the sweetness in your life without adding any calories? And this, from a natural source with the same sweet flavour that your taste buds love? And, yes, with no harmful side-effects? Sounds too good to be true, but nature has gifted us “stevia” – a plant which has sweetness in its leaves – a sweetness that surpasses that of sugar, sugarcane juice, honey or coconut sugar. Also Read – Add new books to your shelfGiven that stevia can replace unwanted sweetener calories, it can be the one tool for cutting calories from the Indian diet without affecting blood sugar or insulin levels. Plus, it is safe for people with diabetes and is also tooth friendly.Here are some of its advantages:Stevia does not increase blood glucose: Numerous studies have been conducted on the use of stevia and its effects on consumption. The stevia plant’s leaves contain naturally sweet molecules called steviol glycosides, which can be up to 400 times sweeter than sugar, but studies have shown that stevia has no effect on blood glucose levels. Thus, one can consume it without fear of affecting the blood sugar level. Also Read – Over 2 hours screen time daily will make your kids impulsiveStevia leaves have almost no calories: It’s a gift of nature that has been used in various parts of the world. The leaves have been used by Guarani Indians in Paraguay for several hundreds of years to sweeten their “matte” (tea). In the 1970s, the Japanese picked it up as a natural sweetening option. Today, it is the No. 1 sugar substitute in Japan and the fastest-growing sweetener in most markets in the developed world like France and the US.Global safety recognition: Stevia sweeteners are permitted for use in foods and beverages in countries around the globe. Over 200 global studies have illustrated stevia’s safety for the entire family. Studies have also shown that it is safe for pregnant women. Stevia is safe for people with diabetes as it does not contain any calories or carbohydrates and therefore does not affect blood glucose or insulin levels. It has zero glycemic index.Stevia v/s artificial sweeteners: Realisation of the harm caused to health from consuming excess calories from sugar was the reason that ignited the search for substitutes, or artificial sweeteners. Saccharin, aspartame sucralose and the like became popular substitutes and then went out of favour owing to concerns from public about their origin and perceived lack of safety.What evidently seals the deal in stevia’s case as a sugar substitute is the fact that it is zero-calorie, zero-fat and 100 per cent natural.Imagine your rossogulla or gulab jamun without an overload of sugar, serving your child tomato ketchup without thinking of the extra sugar and calories, enjoying a serving of ice cream, cool carbonated drink without any sugar at all. The latest varieties of star leaf stevia can make the greatest taste possible without any harm or guilt.However, one must keep in mind that, till date, the research on stevia being a non-nutritive sweetener is still inconclusive. The impact of nonnutritive sweetener on an individual’s health may depend on the amount that is consumed, as well as the time of day it’s consumed. Many stevia products available at the grocery stores have very little stevia in them. They’re made from a highly refined stevia leaf extract called rebaudioside A (Reb-A), which is about 200 times sweeter than table sugar. Reb-A sweeteners are considered “novel sweeteners” because they’re a blend of different sweeteners, such as Reb-A, erythritol (a sugar alcohol), and dextrose (glucose). The U.S. Food and Drug Administration (FDA) says stevia glycosides, such as Reb-A, are “generally recognized as safe.” They haven’t approved whole-leaf stevia or crude stevia extract for use in processed foods and beverages due to a lack of safety information.