RNA reactor could have served as a precursor of life

first_img Copyright 2011 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 This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. (PhysOrg.com) — Nobody knows quite how life originated on Earth, but most scientists agree that living cells did not abruptly appear from nonliving cells in a single step. Instead, there were probably a series of pre-cellular life forms that arose from nonliving chemicals and eventually led to a living cell, one that could undergo metabolism and reproduce. One of the most well-known theories of pre-cellular life is the RNA world theory, which proposes that life based on RNA predates current life, which is based on DNA, RNA, and proteins. But recently, scientists have been wondering what may have preceded RNA. In a new study, a team of scientists from Germany has suggested that the ability to self-replicate may have first emerged in the form of an RNA reactor, which they show can transmit information. Prediction of RNA pseudoknots using heuristic modeling with mapping and sequential folding Citation: RNA reactor could have served as a precursor of life (2011, July 11) retrieved 18 August 2019 from https://phys.org/news/2011-07-rna-reactor-precursor-life.html Explore further More information: Benedikt Obermayer, et al. “Emergence of Information Transmission in a Prebiotic RNA Reactor.” Physical Review Letters 107, 018101 (2011) DOI: 10.1103/PhysRevLett.107.018101 In the RNA reactor, nucleotides accumulate in a narrow pore due to a temperature gradient. Due to bond formation and hybridization of RNA strands, weak information transmission can occur: information can be conserved beyond the lifetime of a single molecule. Image credit: Obermayer, et al. ©2011 American Physical Society The scientists, Benedikt Obermayer, Hubert Krammer, Dieter Braun, and Ulrich Gerland of the Ludwig Maximilians University of Munich, have published their study on the prebiotic RNA reactor in a recent issue of Physical Review Letters.The biggest piece of support for RNA molecules as pre-life forms is that RNA can act as both genes (to store information) and enzymes (to catalyze chemical reactions). Like DNA, RNA is made up of a long chain of nucleotides. However, scientists do not know how a self-replicating RNA system could have arisen from a pool of random polynucleotides.To address this question, Obermayer, et al., have turned to RNA replicators. As described in previous research, RNA replicators can transmit information from one molecule to another so that the information survives even when the original carrier molecules have become degraded. Here, the researchers have investigated how RNA replicators may have arisen from simpler RNA reactors billions of years ago.“We show that a combination of simple physico-chemical mechanisms can greatly facilitate the spontaneous emergence of a prebiotic evolutionary system, such as envisaged by the RNA world,” Gerland told PhysOrg.com.Using computer simulations, the scientists analyzed a scenario in which a hydrothermal RNA reactor emerges with the ability to perform intermolecular information transmission. The scene begins inside porous rocks on the sea floor, where strong temperature gradients produce thermal convection, and the convective flow transports molecules inside the narrow pores. Due to temperature variations, nucleotides in the pores accumulate in a small region and randomly form bonds with one another. Through folding and hybridization, the polynucleotides can form longer sequences, eventually resulting in RNA strands.One of the key factors that allows the formation of RNA strands is the preferential cleavage (splitting) of bonds at unpaired bases. This effect creates a selection pressure for base pairing, and leads to an increase in the complexity and lifetime of RNA structures. One such structure that could emerge as a result is a primitive ribozyme – or “RNA enzyme” – which can catalyze chemical reactions as a component of a true RNA replicator. Most importantly, the computer simulations showed that the RNA reactor can perform weak replication based on information transmission by hybridization of the RNA strands. As the researchers explained, evidence of information transmission appears as an unexpected increase in the lifetime of certain sequences.“Hybridization simultaneously protects a sequence motif and its complement from degradation,” Gerland explained. “Thereby, it extends not only the lifetime of the sequence motif, but also the lifetime of its complement, which in turn can protect other copies of the sequence motif after dissociation. This constitutes a form of information transmission between molecules, since it can conserve the information in the sequence motif beyond the lifetime of a single molecule.”Overall, the computer simulations showed that the prebiotic RNA reactor could serve as a stepping stone toward the emergence of a true RNA replicator. Acting as a filter to keep potentially useful sequences of nucleotides, the RNA reactor could lead to complex sequences, such as ribozymes. Once ribozymes emerge from an RNA reactor, they could establish an efficient self-replicating system in the form of an RNA replicator. In the future, the researchers hope that they might be able to experimentally demonstrate such a process.“The experimental investigation of this scenario is indeed a very exciting direction to explore,” Gerland said. “We believe it is possible to realize essential aspects of the scenario in the lab, on a small scale. We are working towards that end.” 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

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Samsung tablet concept shows a seethrough bendable future w video

first_img 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. With all the visual interest going on in this video, the most attention among bloggers and mobile device enthusiasts is being centered on the bendable, AMOLED (active-matrix organic light-emitting diode) display. Explore further Samsung Flexible AMOLED Display at CES While some bloggers wonder why, beyond novelty, they and others would want to have a device that bends, some strong reasons are easily found from those tracking new technologies in mobile devices. Louis Bedigian of Benzinga lists some key advantages. Bendable screens can withstand impact and be less likely to break or crack; bendable screens open up new possibilities in wearable computing; new applications, especially in gaming, can leverage the screen’s physical flexibility. Users can not only tilt and twist but bend the screen to influence gaming elements. Nokia has also been teasing away in promoting a similar future of smart devices with concepts of flexible, bendable phones. Also, according to reports, the firm’s research and development unit, the Nokia Research Center, has been working with scientists at The University of Cambridge to create products that can change the appearance and interface of handsets. Besides exploring technology that allows a phone to be controlled by squeezing and twisting, Nokia is reportedly exploring technology involving wearable phones. Foldable display shows no crease after 100,000 folding cycles © 2011 PhysOrg.com Citation: Samsung tablet concept shows a see-through, bendable future (w/ video) (2011, December 5) retrieved 18 August 2019 from https://phys.org/news/2011-12-samsung-tablet-concept-see-through-bendable.html (PhysOrg.com) — A Samsung smartphone-ish, tablet-ish sized device is see-through, bends at will, and changes size according to what kind of app you want to use. Lest we forget, the device translates, explores, and locates, among other things. It shows images on either side, at the same time. Really? Yes, but. Samsung has released a concept video of a transparent, flexible 3D AMOLED display based tablet of the future, not anywhere near now. The video shows a user walking around the streets brandishing his wafer-thin see through rubbery device that is sized somewhere between smartphone and tablet, performing a range of tasks that connects him to people and places. That is where mobile devices are headed in the near future, even though the concept device shown in the Samsung video, with all its bells and whistles, may be far off.OLED is a display technology and the “active matrix” points to the control of pixels. AMOLED technology is already in use and is seen as becoming a staple in the new generation of screen displays, Samsung considers itself the leader in AMOLED technology.The company demonstrated ‘bendable’ AMOLED screens earlier this year. According to numerous reports, bendable AMOLED smartphones from Samsung are due in 2012. last_img read more

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Human hybrids a closer look at the theory and evidence

first_imgThere was considerable fallout, both positive and negative, from our first story covering the radical pig-chimp hybrid theory put forth by Dr. Eugene McCarthy, a geneticist who’s proposing that humans first arose from an ancient hybrid cross between pigs and chimpanzees. Despite the large number of comments, here at Phys.org, on macroevolution.net, and on several other discussion forums, little in the way of a scientific consensus has emerged. By and large, those coming out against the theory had surprisingly little science to offer in their sometimes personal attacks against McCarthy. 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. The objection that mating between such different animals is just too strange has been addressed at length on McCarthy’s website. Ample counterexamples have been given there and elsewhere, including the evidence for matings, without issue, between such strange pairings as a buck rabbit with female cat (or even with a domestic hen), or a dog with a monkey, or with a swan goose. In general, as McCarthy points out, it has long been known that many organisms, as adults, prefer to mate with whatever animal they are exposed to at the critical early stage in their lives when sexual imprinting occurs.He also notes that it is not as if his hypothesis that humans are pig-chimp hybrids has not been tested. Under the alternative hypothesis (humans are not pig-chimp hybrids), the assumption is that humans and chimpanzees are equally distant from pigs. You would therefore expect chimp traits not seen in humans to be present in pigs at about the same rate as are human traits not found in chimps. However, when he searched the literature for traits that distinguish humans and chimps, and compiled a lengthy list of such traits, he found that it was always humans who were similar to pigs with respect to these traits. This finding is inconsistent with the possibility that humans are not pig-chimp hybrids, that is, it rejects that hypothesis.Also raised was the argument that pigs and humans might have converged anatomically as a result of longstanding animal husbandry, not limited to but perhaps including genes carried over by retroviruses. If that is, in fact, a general mechanism that operates behind the scenes, then we might justifiably ask—why don’t a lot of the traits that distinguish us from primates connect us with dogs, with whom we have obviously lived, at close quarters, since prehistoric times? Why is it only pigs?One objection which seems to have really stretched the genetic exclusion argument was an appeal to junk DNA as a mechanism that can prevent two species from reproducing. The reference was to a paper in PLoS Biology which revealed interesting phenomena occurring in Drosophila (fruit flies) that can prevent embryos from developing. The study points to faster mutation rates found for noncoding DNA, and outlines a mechanism where mutation in a segment on the X chromosome of the father prevents proper separation of the whole chromosome. Clearly, a unique situation in this particular species, however interesting, does not invalidate the documented existence of successful hybrids produced in thousands of other species crosses.In moving forward, we hope to see more discussion on this issue from both sides of the argument. Nothing is preventing anyone from taking a closer look at the genetic picture. In fact, doing so has never been easier. Sites like eEnsembl let you “browse a genome” with unprecedented ease. Sequence data, or genome organization can be curated to support both observation and idea, as it can also be done to oppose the same. For the matter at hand, we might expect each side to continue to accuse the other of cherry-picking their arguments. Eventually though, sufficient data will fall from the collisions between example-fed discussion and informed search to deliver an elevated consensus. One particular approach recommended McCarthy is in silico chromosome painting of the human genome with random pig and chimp sequences in an effort to find hotspots of similarity to pig.Another possibility that McCarthy does not recommend, but which several scientists have suggested to him, is producing an actual hybrid. He objects to this approach, not on scientific, but humanitarian grounds. After all, he says, such an experiment might result in an intelligent but non-human creature, much more piglike than any human being, who would have no happy place in our world. He in fact includes such a hybrid, an F1 female, as one of the major characters in The Department, his kindle book satire of academic life. In it he observes, “I hope never to meet her in the flesh.” You can see McCarthy address some of the issues raised above in greater depth in a podcast that has just been released. As any skilled listener might observe, the most important thing in communication is not always hearing what is said, but rather, hearing what isn’t said. One thing we have not heard here is objection from those writer-scientists who have any kind of public reputation in the evolutionary sciences. I don’t think that is because they didn’t hear about the story. Talk show host Jimmy Kimmel found the article, or at least parts of it, to be rather revealing, and he used segments from it on his show. Commenters on the O’Reilly Factor also called in asking for his opinion on the story. The reason for the silence from above, so to speak, is that they have nothing to gain in being right, but much to lose when any statement they might offer is picked apart by someone with a little more conceptual fluidity, and who has substantial research vested in the theory.As many critics noted, the advancement of scientific knowledge does not require disproving every radical theory that comes along. Lots of incorrect theories exist that cannot, for all practical purposes, be formally disproven. It seems, however, that decent arguments against the hybrid origins theory are surprisingly hard to find, and moreover, the established elders of the field, well, they know it. We decided it would be worthwhile to take a closer look at the objections that were most commonly offered against the hybrid hypothesis. Chief among them was that the chromosome differences here are just too large to support a viable hybrid. One of the previous examples we gave, the zedonk (zebra parent, 2n=44, donkey parent, 2n=62), can and does result in female hybrid offspring that have been reported to produce offspring in backcrosses. The same is true for the geep (sheep, 2n=54, and goat 2n=60). While the reduction in fertility associated with large differences of this sort is often severe, the existence of fertile hybrids, particularly in backcrosses, invalidates this objection. More information: www.macroevolution.net/ , PLoS Biology Explore further A chimp-pig hybrid origin for humans?center_img Citation: Human hybrids: a closer look at the theory and evidence (2013, July 25) retrieved 18 August 2019 from https://phys.org/news/2013-07-human-hybrids-closer-theory-evidence.html Journal information: Nature Credit: ristorantemystica.wordpress.com © 2013 Phys.org Another argument was that the morphological distance, or genetic differences besides chromosome number, are just too great. Most of us are familiar with the platypus. A paper published in Nature a few years ago demonstrated that the platypus genome contains both bird and mammal chromosomes, and therefore that the vastly different bird and mammal sex chromosome systems have been successfully bridged by this creature. This example is not offered as any kind of proof. But it does suggest that sometime, long ago, a cross occurred that would have been even more distant than that between a chimpanzee and a pig – one between a otter-like mammal and a duck-like bird. And if such was the case, the hybrids from the cross must have been able to produce offspring (otherwise they would have died out, and the platypus would not exist today). Credit: http://www.skullsite.co.uk/Pig/pigdom.htmlast_img read more

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Philips LED bulb with rad design set for January arrival

first_img 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. (Phys.org) —Netherlands-based Philips’ SlimStyle LED bulbs will be arriving on January 2 at Home Depot stores, and the SlimStyle appears to be a promising newcomer in lightbulbs, with a flat design, energy-saving benefits. and ease of use for consumers. Intended as a replacement for 60- watt incandescents, SlimStyle is highly efficient; it uses only 10.5 watts, yet still puts out 800 lumens. Explore further Kickstarter project team claims its LED bulb world’s most efficient Citation: Philips LED bulb with rad design set for January arrival (2013, December 17) retrieved 18 August 2019 from https://phys.org/news/2013-12-philips-bulb-rad-january.html This lightbulb is shaped such that a string of LEDs are arranged into a horseshoe shape that arc out from the base. The shape is not just about grabbing attention; the technical advantage is that the SlimStyle does a good job in dispersing heat and does away with the need for heavy heat sinks. In a GigaOM report on the SlimStyle, a Philips spokeswoman e-mailed comments about the bulb’s design “The flat surface,” she said, “helps conduct heat away from the LEDs, eliminating the need for the heavy aluminum heat sinks associated with LED bulbs. This eliminates the cost of the bulb, while still delivering omnidirectional light.” Illumination in Focus further reflected on the significance of the design: “Philips has once again created an LED-based retrofit lamp with a novel shape that still delivers an omnidirectional beam that the company expects to win Energy Star certification. The design looks somewhat akin to a doughnut on top of an Edison base although there is only a flat area rather than a whole in the center of the doughnut. The solid-state lighting (SSL) design enabled a new approach to thermal management that does not rely on a visible metal heat sink.”Chris Davies, meanwhile, writing in SlashGear, had a look at the SlimStyle, and observed still another advantage in its design, and that is its ease of use for those who may otherwise struggle with conventional bulbs. The elderly or infirm with weak grips, for example, might find the SlimStyle easier to manage with just a twist. The plastic body, too, will feel sturdy enough so that the user does not worry about cracking or breaking the bulb while handling it.The introduction comes at a good time for Philips, as 2014 in the US also marks the point when 60- and 40-watt incandescent bulbs will be phased out. In 2014, the bulb will no longer be manufactured or imported. That also means that consumers in 2014 will be especially interested in finding alternative “green” LED fixtures and can expect promotional messages of better efficiency, The phaseout is In line with the Energy Independence and Security Act of 2007.This Act is designed to help raise the efficiency of products, buildings, and vehicles. © 2013 Phys.orglast_img read more

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The sparrow takes flight

Sakshee Pradhan’s Schon [meaning beautiful in German] takes inpiration from little sparrows and spring that dominates her entire collection in the form of delicate cut outs of the bird that graced every piece of the looks showcased. Predominantly is salmon pink with well places swatches of shimmer, sheer and champagne sequins -the collection falls beautifully but the colour tends to get a little monotonous after a point. One delicate gown in an ivory white with sparrows in colour on branches is striking. Diana Penty as showstopper flowed on the ramp in her ensemble – but we really wish the collection had a little more edge to stand out. read more

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The Crucible comes to capital

first_imgThe three-hour performance by the final year students of the coveted NSD is a reflection of our society where emotions of greed and jealousy are overpowering human values.‘In his play Miller had shown how innocent people were killed and jailed during the witchcraft trails. This play focuses on the silent method adopted by many Indian states to push poor people out of the system,’ its director, Santanu Bose said.A witch or ‘daayan’ is used as a metaphor in the play to showcase how witchcraft can be used as a tool to denounce people and make them outcasts. Also Read – ‘Playing Jojo was emotionally exhausting’‘Even Miller used the garb of a witch through this play to showcase political insensitivities during the trials. He couldn’t have been upfront about the injustice, so he used his play as a tool to tell the story,’ pointed out Bose who also teaches at NSD.Miller’s 1953 production had initially received hostile reviews because of its obvious reference to the Salem witch trials – mass hysteria that led to a series of hearings and prosecutions of people accused of witchcraft in Massachusettes. Also Read – Leslie doing new comedy special with NetflixBose found similarities of in rustic Jharkhand and felt the setting was apt for his play.‘I could have chosen any place in south or anywhere in India. But Jharkhand relates well with the settings of Miller’s play,’ he noted.‘I need a place where industrialisation, indigenous community, superstitious beliefs and ulta-left politics were prevalent,’ he added. Hence the four-act play treads same path as Miller’s.Betty Parris, the one believed to be under the spell of a witch becomes Rupa, and Abigail, the niece of the temple’s priest, becomes Savitri in Bose’s play.The characters of the play have adapted well to the local dialect of Jharkhand, their ways of living and dressing. There is an ease with which each character plays his role.last_img read more

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World Book Fair to focus on childrens literature

first_imgThe nine-day fair organised by the National Book Trust in association with the India Trade Promotion Organisation (ITPO) is particularly themed ‘Kathasagara: Celebrating Children’s Literature’ this year. Approximately 25 countries are participating this year with Poland being the guest country. A contingent of  around 25 people including authors, illustrators and publishers are participating from Poland in the fair.Speaking on the occasion, the President said, ‘We must be uncompromising in rejecting intolerance, prejudice and hatred. Book fairs such as NDWBF should remind us that our history and traditions have always celebrated the ‘argumentative’ Indian and not the ‘intolerant’ Indian. Multiple views, thoughts and philosophies have competed with each other peacefully for centuries in our country and freedom of speech is one of the most important fundamental rights guaranteed by our Constitution.’ Also Read – ‘Playing Jojo was emotionally exhausting’Congratulating the organizers for having chosen children’s literature as the theme for this year’s fair, Mukherjee said that no human society can develop in all dimensions if it does not produce meaningful literature. He appealed to parents and teachers to inculcate in children the habit of reading. He said implanting the habit of reading in children will ensure that it becomes a skill that stands them in good stead throughout their lives.Commenting on the fair the director of the Polish institute, Anna Tryc-Bromley said ‘We see this Fair not only as a feast of literature but also as a historic opportunity for Polish and Indian publishing industry to meet.’last_img read more

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Art within reach

first_imgIt is time for Gallerie Nvya’s much awaited annual show Within Reach driven with the intention of displaying well priced works of masters alongside new works by emerging artists . The quality as well as the priceline of the art works is the main criteria of selection. Within Reach, in its fifth year, is targeted essentially at discerning collectors who want to collect remarkable works at incredible prices! The art works are in varied genres and mediums like paintings, drawings, serigraphs, sculptures and installations. And the works come from a host of 50 artistes from across the country.  Also Read – ‘Playing Jojo was emotionally exhausting’Priced reasonably, each of the works is selected after serious deliberation on the individual profile and work corpus of the respective young artist. For Nvya this is an opportunity to share and make available art that stands on the threshold of recognition and is filled with promise. Through the show they provide a platform for emerging artists in a space shared with more established names; affirm aesthetic sensibility, and celebrate the creative impulse that weaves colour and form into variegated manifestations of visual reality.Art galleries had a formidable aura in earlier times, a standoffish, snobbish setup which was interpreted as elitist by many, especially the young and not so affluent. With passage of time, this has changed to some extent. Gallerie Nvya has made this little endeavor with the Within Reach series of exhibitions to modify and revise this myth. Whether you are buying a piece or not -head over!last_img read more

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Important bills have to be passed to maintain growth Venkaiah

first_imgUnion Minister M Venkaiah Naidu on Friday said important bills like GST Bill and Real Estate Bill need to be passed for economic development, even as he noted that 30 per cent of Indians live below the poverty line.“We have 30 per cent of Indians living below poverty line. The government has recorded 7.3 per cent GDP growth. If the same pace of growth is continued for two to three years, there is a possibility of India overtaking China’s growth rate,” he said. Also Read – Punjab on alert after release of excess water from Bhakra dam“Initially, the government faced a lot of problems like fiscal deficit, revenue deficit, trade deficit, current account deficit and a trust deficit. We must pass GST Bill, Real Estate Bill and Negotiable Instruments Bill. Mudra scheme has to be strengthened further,” he said. He said that contrary to public notion that large industries create more employment opportunities, it is small enterprises which employ as many as 12 crore people.“It is the small enterprise sector which our PM wants to target through the Pradhan Mantri Mudra Yojana in order to help budding entrepreneurs,” he said.last_img read more

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Bandh day 2 Attempts fail to hamper normal life services

first_imgKolkata: The second day of the bandh called by the opposition trade unions had no impact across the state including Kolkata. In several areas, the bandh supporters resorted to hooliganism to obstruct vehicular movement.In Rajabazar, the bandh supporters attacked a pool car carrying school children. One child was injured by the stone pelters supporting the bandh. Transport service remained normal and more government buses were pressed into service. Also Read – 3 injured, flight, train services hit as rains lash BengalThe State government offices, educational institutions and even private companies recorded normal attendance. The IT sector and Port activities were normal and so was the attendance at tea gardens. Attendance at Nabanna, new Secretariat buildings and other state offices at different parts of the city and the state recorded above 95 percent of attendance. On Wednesday morning, the bandh supporters again tried to put up a blockade by organising a rally at Jadavpur led by CPI(M) leader Sujan Chakraborty. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedPolice immediately intervened and dispersed the mob. Several CPI(M) leaders and cadres have been arrested including Chakraborty. In Rajabazar, the SFI workers and leaders resorted to hooliganism to make the bandh a success. They even attacked a pool car carrying several nursery students to school. It is alleged that the bandh supporters pelted stones at the pool car. As a result, the windshield and other glass windows broke. One child got injured and was immediately rushed to Calcutta Medical College Hospital where the doctors treated him. Later, police arrested the SFI leaders. Train service was partially affected in the Sealdah and Howrah section. Howrah Division was made obstruction free by 8:10 am and Sealdah Division was made the same by 12:30 pm. On Wednesday morning, the bandh supporters allegedly placed bombs on the railway track near Habra railway station. Due to this train services got disrupted in the Bongaon section for almost three hours. In the Ranaghat section, the bandh supporters put up a blockade at Ranaghat and Simurali station. Banana leaves were thrown on the overhead electric wires. In the Sealdah South section, train services got disrupted at Lakshmikantapur and Namkhana. In Basuldanga, the bandh supporters placed concrete slabs on the railway tracks and put up a blockade. Later, Railway Protection Force (RPF) personnel dispersed the mob and normal train movement commenced after almost an hour. Over 10,000 police personnel were deployed in the city along with an additional force of 5,000 to prevent any untoward incident. Kolkata Police arrested 99 persons in connection with attempts of enforcing the bandh on Wednesday. In the Hills, the bandh failed to make an impact. Shops, offices, business establishments and educational institutes remained open. There was normal traffic on the road. Tea gardens in the Hills also remained open.last_img read more

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