Monthly archives: August, 2019

Snakes heat vision enables accurate attacks on prey

first_imgHowever, pit organs work a little differently than pinhole cameras in that incoming radiation does not strike a single point on the membrane. Because the pit hole is very large compared to the membrane size, the radiation strikes many points. When detecting pointlike and even non-pointlike objects, it’s nearly impossible to tell the location of the heat source. Until now, scientists did not know how snakes could use this heat vision to make accurate attacks on their prey. Sichert, Friedel and van Hemmen confronted this paradox—that the optical quality of the infrared vision is much too blurry to allow snakes to strike prey with the observed accuracy of about 5 degrees. In order to develop an algorithm to explain the paradox, the scientists decided to work backward: by using solely the heat distribution on the pit organ membrane, they reconstructed the original 3D spatial heat distribution (e.g. rabbit shape, as shown in the figure). Because they used very simple computations similar to those of snakes, the group generated an image similar to what the snake “sees” with its neuronal map via its network of synapses.By including several variables, including background noise, the snakes’ measurement errors, and correlation of the input signals, the scientists then developed a neuronal algorithm that accurately reconstructed the heat image from the membrane. Whereas the group found that snakes have a fairly high input-noise tolerance, they found that one of the most vital requirements is accurate detectors and the ability to detect edges in the images produced on the pit membrane.“A heat distribution in 3-dimensional space causes a heat image on the pit membrane that, by the very nature of the big pit hole, is heavily blurred,” said Sichert. “A superposition of edge detectors in the brain can now reconstruct the heat distribution by using the whole image on the membrane for each point in space to be reconstructed. So reconstruction is possible because the information is still available in the blurred image on the pit membrane, where the receptors are.”In fact, Sichert added that snakes’ heat vision presents such a clear image when reconstructed that it surpasses even many human devices. “The infrared system of snakes is still as good as—and, in fact, far better than—any technical uncooled infrared camera with a similar number of detector cells,” he said.Citation: Sichert, Andreas B., Friedel, Paul and van Hemmen, J. Leo. “Snake’s Perspective on Heat: Reconstruction of Input Using an Imperfect Detection System.” Physical Review Letters. 97, 068105 (2006).By Lisa Zyga, Copyright 2006 Explore further The detection system, which consists of cavities located on each side of the head called “pit organs,” operates on a principle similar to that of a pinhole camera, explain scientists Andreas Sichert, Paul Friedel and J. Leo van Hemmen in a recent issue of Physical Review Letters. A pinhole camera is a camera without a lens, where light from an image passes through a very small hole. Similarly, a pit organ’s aperture is about 1 mm—large enough to allow the snake to quickly detect moving prey. Some scientists (de Cock Buning) even suggest that pythons—a type of boid—have a variety of differently shaped pit organs, each serving a different biological function.“The information of the infrared and the visual system are both represented in the optic tectum,” Sichert told “This information forms a neuronal map, where, for example, the front part of the optic tectum represents the part of visual space in front of the snake. How exactly the two systems merge is as yet unknown. In the optic tectum, six classes of tectal cells have been identified that respond to infrared and visual stimuli in different ways. So a snake can get additional information such as ‘is a moving visible object warm (e.g., a warm-blooded animal) or cold?’ In case of bad optical conditions (most prominent example is darkness), it can of course ‘see’ warm (or cold) objects.” Researchers make a water filter from the sapwood in tree branches The image at left shows a figure as captured by a snake’s pit organ. When Sichert and colleagues applied their algorithm (similar to calculations in a snake’s brain), they reconstructed the image of a rabbit at right. (The illustration is based on a photo and does not correspond to a realistic thermal profile.) Image credit: Sichert, Andreas, et al. Call it a sixth sense, or evolution’s gift to these cold-blooded reptiles: some snakes have infrared vision. Also called “heat vision,” the infrared rays, which have longer wavelengths than those of visible light, signify the presence of warm-blooded prey in 3 dimensions, which helps snakes aim their attacks. Pit vipers and boids, the two snake types that possess this ability, have heat-sensitive membranes that can detect the difference in temperature between a moving prey—such as a running mouse—and its surroundings on the scale of milliKelvins.center_img The scientists explained that typical prey, such as mice and rabbits, have a surface temperature of about 25 degrees C and emit body heat at wavelengths under 75 micrometers, in the infrared range. “If the radiation intensity hitting the membrane at some point is larger than the emitted thermal radiation of the membrane itself, the membrane heats up at that location,” the scientists reported in their study. In pit vipers, which have only two pit holes (one in front of each eye), a block of about 1,600 sensory cells lie on a membrane which has a field of view of about 100 degrees. This means the snake’s brain would receive an image resolution of about 2.5 degrees for pointlike objects, such as eyes, which are one of the hottest points on mammals. The head of this pit viper shows a nostril, pit hole and eye (left to right). In the sketch at right, radiation enters the pit organ and hits a heat-sensitive membrane. Because point-like objects spread out into disc-shaped images on the membrane, images are blurry. Scientists recently found that edge detectors in the brain must reconstruct the heat distribution from blurry images to inform the snake of greater detail of its surroundings. Image credit: Sichert, Andreas, et al. Citation: Snakes’ heat vision enables accurate attacks on prey (2006, August 31) retrieved 18 August 2019 from 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 New Kind of Quantum Pump

first_img“We hope to apply quantum pumping to quantum computing architecture,” Ari Mizel, a professor at Penn State tells In a world where scientists are striving to build quantum computing mechanisms and processes, various blueprints are on the table. And one of the integral parts of any quantum computing scheme is entanglement. Along with his student Sungjun Kim at Penn State and his postdoctoral researcher Kunal Das, now an assistant professor at Fordham University, Mizel proposes a quantum pumping method of delivering entangled electron pairs for use in quantum computing. A method that provides electron pairs and eliminates the background noise associated with single electron transport. Their findings are published in a Letter titled “Controlled Flow of Spin-Entangled Electrons via Adiabatic Quantum Pumping,” in Physical Review Letters.“Quantum pumping,” explains Mizel, “is a lot like swallowing. Electrons are in a channel, and as the walls deform periodically, it pushes stuff down.” Quantum pumping itself is not brand new, although the idea is a relatively recent development. Different experimental groups have been working with quantum pumping and use it to push charge or individual electrons with spin. What is different about the model of Kim, Das, and Mizel is that it would work by gathering paired electrons only, rather than “grabbing” single electrons and pumping them as well. Mizel’s team proposes a quantum pumping method that eliminates the transport of these single electrons that can provide background noise and increase decoherence.“We worked out a way to grab a couple of carriers at a time by changing interactions between the carriers,” says Mizel. The channels that hold the electrons are contorted, and the oscillations force the electron pairs through, carrying entanglement. Mizel explains, “The energy of individual electrons is not changed by the contortions. There is a counterbalance, so the individual electrons don’t feel the change. The electron pairs, though, feel it and get mushed closer together. Then the oscillations force them down and through.”This method would make it easier to eliminate non-entangled electrons. Right now, the background noise they create either has to be accounted for, or scientists attempt to catch and remove individual electrons. With this method devised by Mizel, Kim and Das, there would be no need to try to remove individual electrons; the carriers would just leave them behind, creating better entanglement. “There would be a stream of pairs, an individual electron will only feel contortion if it’s in proximity to a second electron. Then the carriers would be pushed down in groups.”Mizel admits that right now, this idea is in the theoretical stage. “We try to talk to people at conferences, and we’re familiar with who’s been doing quantum pumping in the past. Hopefully we can get some interest in this.” And it shouldn’t be that difficult. While Mizel concedes that this method of quantum pumping would be challenging to instigate, he also points out that it is not far beyond current scientific capabilities. “This doesn’t require any bold, brand new technology,” he insists. “It’s not far outside the possibilities. It would be interesting to see what could be achieved by this method.”Citation: Kunal K. Das, et al., Controlled Flow of Spin-Entangled Electrons via Adiabatic Quantum Pumping, Physical Review Letters, 97, 096602 (2006)By Miranda Marquit, Copyright 2006 Citation: A New Kind of Quantum Pump (2006, September 19) retrieved 18 August 2019 from 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 Explore further Digitally programmable perovskite nanowire-block copolymer compositeslast_img read more

Going the Mijwan way

Well, to start with, nothing that Malhotra showcased on finale show of Day II can exactly be called new. The show was to promote his works with the Mijwan Welfare Society, the NGO founded by poet and lyricist Kaifi Azmi. We expected more  Bollywood touch but only got Parineeti Chopra walk the ramp in a lehenga and Salman Khan’s ex-flame Sangeeta Bijlani on the front row. The show started with men showcasing bandhgalas and sherwanis with lots of chikankari work which has been done by girls from Mijwan. Malhotra used khadi, silks, velvets to create jackets, trapeze pants, saris, knee-length kurtas and lehengas. read more

How about some water conservation

first_imgFrom cracking jokes to business deals, we Indians love talking, and we talk about everything under the sun. Let’s for a change today talk about something as important as life itself – Water. Should we care? We must, each one of us, says Vivek Mishra MD/Technical Head Premium Pools. When so much is happening around us, don’t you think it’s time we as individuals contribute in our own capacities before we actually reach a stage when we would either be fighting or paying for water as a luxury item. Also Read – ‘Playing Jojo was emotionally exhausting’Water conservation has had negative connotations for many people because it unintentionally implies hardship and inconvenience associated with it. However, conserving water is not simply a matter of using less water through restrictions. It is about careful management of water supply sources, use of water saving technologies, reduction of excessive demand and many other actions. Water conservation is the responsibility of both water users and suppliers. Also Read – Leslie doing new comedy special with NetflixWith pools, the only way to ensure happiness is by taking care of durability, comfort and long term cost benefits. This can only be done by choosing the right builder at the onset. Hardly people in India realise that ideally a pool should never be emptied. In a pool with proper filtration and plumbing, water is changed only a couple of years.  In Indian climate conditions one can consider emptying the pool to harvest rain water. Given that they are built right, pools can help. But a bad pool can leave you helpless.last_img read more

Celebrating cinematic excellence

first_imgA warm farewell to Delhi International Film Festival (DIFF) 2014 was given by many eminent personalities like Tigmanshu Dhulia, Meera, Taslima Nasreen, Khalid Mahmood Mithu, OP Mishra (director of NDMC), Vinod Goyal (Commissioner of Customs in Central Exercise), Sangeeta Gupta (Commissioner of Income Tax), Bouthaina Al (Deputy Chief of Mission Morocco Embassy, India), Rajeev Gupta (actor) and Bharati Taneja. A total of 28 awards in various categories that includes films, art, literature, photography and fashion were given at the grand finale that took place at NDMC Convention Centre in the Capital. Also Read – ‘Playing Jojo was emotionally exhausting’The closing ceremony began with National Award Winner Filmmaker, Tigmanshu Dhulia receiving Special Honor award for his contribution to Indian Cinema. Tigmanshu who is the brand ambassador and founder member for DIFF, addressed the media and stressed upon the fact of creating a film city in Delhi and the support the kid on the block DIFF 2014.On receiving the best actress Award Meera Ali, expressed herself, “I am glad to receive this Award at the Delhi International Film Festival, I am thankful to India for giving me this award, my first award by India. I was honoured with many awards in my country Pakistan, but here I am really grateful to Ram Kishore Parcha ji for honouring me and all credit  goes to Khalid who made a fabulous film”. Also Read – Leslie doing new comedy special with NetflixDIFF 2014 was planned as an eight Day event and showcased 250 films from more than 45 nations. It was an initiative by ‘The Social Circle, A Society for Cause and – A step toward inclusiveness’ to showcase the best of Cinema, Art and Literature from across the globe.Started in the year 2012, the advisory board for this festival is headed by Dada Sahab Phalke awardee Adoor Gopal Krishnan. Working closely with him are some of the greats of Indian Cinema namely  National award winning director Tigmanshu Dhulia, Anurag Kashyap, Anooj Kapoor, Mohan Agashe, Manoj Bajpai,  Shriram Raghwan, N. Chandra, Sandeep Marwah, Shailesh Loadha, , Arvind Gaur  with Jamal Shah and Satish Anand from Pakistan. Awards was given in various competitive categories as the ‘Life Time Achievement Award’ was presented to Subhash Ghai, ‘Special Honour Award’ to veteran actor Biswajeet and a special award called ‘Minar-e-Dilli’ was  conferred to Olympic Medallist,   Sushil Kumar.The festival began with Ilan Yagoda’s Israeli film The Neighbourhood and a short Greek film The Sun and The Wind directed by Thansis Neophotolistos. Critically acclaimed film, Zinda Bhaag from Pakistan starring Naseeruddin Shah and directed by Meenu Gaur was the closing film for this edition of the festival. The festival also screened films on social issues, book launches, and workshops on wildlife photography and animation and special Seminar to promote Delhi as Film City.last_img read more

Revised vehicle fares implemented in city

first_imgKolkata: The hike in the fare of bus and other public transport vehicles was implemented on Monday, with most of the commuters accepting it.The state government was compelled to give its nod for increasing the fare of bus and other modes of transport, as the Centre “remained indifferent” in bringing down the diesel price.The decision to increase the bus fare was taken following a high level meeting held in the state secretariat Nabanna. Chief Minister Mamata Banerjee, the state Transport minister Suvendu Adhikari and representatives of bus operators were present in the meeting. Also Read – Heavy rain hits traffic, flightsAdhikari had apologised to the people of Bengal, stating that they had to give its nod for increasing the bus fare despite their unwillingness, as the Centre has done nothing to bring down the prices of diesel, despite repeated requests.It was on June 8 that the state Transport department had issued the notification, finally declaring the hike in the fare. The minimum bus and mini-bus fare was increased to Rs 7 and Rs 8 respectively. At the same time, the minimum taxi fare increased to Rs 30 and it is for the first 2 km. At the same time, taxi fare for every additional 0.2 km has become Rs 3 and the luggage charge has become Rs 5. Similarly, there was minimum increase in the fare for tram and ferry services as well. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedWith the news spread about the increase in fare, the commuters were prepared to pay more to travel from one point to another. The new fare chart was put up in all the buses and commuters were found checking the same before paying their fare on the first day after the fare was increased. Taxi drivers were also found explaining to the commuters the increase in the fare.Madhumita Ghosh, teacher of a private school, said: “The state government had nothing to do apart from increasing the fare as buses need diesel to ply and its price has skyrocketed.”Manojit Ghosal, a helper of a private bus, said: “The increase in the fare has not left any affect on the number of passengers.”last_img read more

Handloom push

first_imgThe handloom sector plays a very important role in the country’s economy. It is one of the largest economic activity providing direct employment to over 70 lakhs persons engaged in weaving and allied activities. Handloom Industry is the symbol of self reliance and generates employment for millions of small weavers. A panel discussion on Revival of handloom and increasing earning of the the Handloom weavers, was recently held at the India International Centre, where the panelists were Ritu Kumar, eminent Fashion Designer, Sudha Pillai, Retd. IAS, Member Secretary of Planning Commission, Jaya Jaitley, Founder – President of  Dastkari Haat Samiti, Anita Lal,  the founder of Good Earth, along with SK Panda, IAS, Secretary, Ministry of Textiles.  Also Read – ‘Playing Jojo was emotionally exhausting’“The economy of Panipat is based on several industrial agriculture, tourism and handloom. The city is famous for ‘panja durrie’, a kind of floor covering, which is in great demand in India and abroad. Originally, it was a traditional item made by village women but slowly the  product came to be recognised beyond Panipat and growing demand for durries resulted in a burgeoning numbers of private and state owned weaving units within the city,” said SK Panda, IAS, Secretary, Ministry of Textiles.  Also Read – Leslie doing new comedy special with NetflixFashion designer Ritu Kumar noted, “Handloom goods are the important cottage and home industries taken up by the people. Among the women folk, handloom cloth weaving is the traditional occupation of the district. The whole handloom industry survives on heavy subsidies today, as it has always done.”Jaya Jaitley, founder-president of the Dastkari Haat Samiti shared how she brought into being the vibrant Dilli Haat where crafts are displayed and sold in the atmosphere of a mela.  Author of the book The Artistry of Handwork, she further explains, “We take things for granted and don’t perceive what is around us. This book helps us notice, and feel happy about the simple beauty of craft.”But the question which lingers is… ‘People are willing to spend so much in malls on diffrent products and they don’t bargain. Why not on crafts that help form our identity and culture?, to which  Sudha Pillai, Retd. IAS, Member Secretary of Planning Commission commented, ‘Many exhibitions needs to be showcased, which displays applications on metal, wood, clay, woven textiles and traditional art. There are hand block-printed and embroidered textiles from Rajasthan, hand-woven textiles from Varanasi, terracotta from Kerala, leatherwork from West Bengal, Madhubani art, hand-painted and natural-dyed textiles in Kalamkari from Andhra Pradesh, Pattachitra from Orissa, painted wooden objects from Kashmir and plenty more to choose from.’last_img read more

Housing Doon students unique initiative

first_imgJayadityavir Singh, a student of The Doon School, Chand Bagh, Dehra Dun has come up with an initiative which uses plastic bottles filled with mud and other wastes instead of bricks for the construction of homes. Titled-Project Plastech, the main focus is to cut down costs of construction in which bricks is an integral part.“In this initiative we fill plastic bottles with any form of sand or waste and then we use these bottles as substitutes for bricks,” said Jayadityavir Singh. Also Read – ‘Playing Jojo was emotionally exhausting’He reveals that Plastech is an initiative that aims at working towards providing sustainable cost-effective housing from a completely different perspective. This initiative places emphasis on the use of plastic bottles as substitutes for bricks, thereby cutting down total costs by a significant amount. It started for the sole purpose of providing housing cheaply for the underprivileged and the needy. The economic aspect as well as the relative cost cuts serve as great pluses from which this initiative can appeal to the masses.  Also Read – Leslie doing new comedy special with NetflixHe reveals the level of skepticism he had to face regarding this project, he said: “Yes, we tend to have a large amount of skeptics when we describe our technology, but as you continue to read and see our various projects, it will be clear that we, indeed, know what we’re talking about. This initiative has several other advantages, the use of plastic bottles mean there will be a significant reduction of bricks being baked, minimising the carbon dioxide emissions.” A great problem faced by farmers and agriculturists in our country today is the lack of top soil cover in states to provide adequate incomes for farmers and people related with agriculture in India as a whole. This is primarily due to majority of farmers selling off top soil to brick kilns. These kilns require top clay soil in order to bake bricks, but this has adverse affects on the  yieldsof the land.It tends to amplify into butterfly effect hampering the productivity per hectare of farmers all around the country and obviously pushes the productivity of the country backward in terms of yields per hectare.last_img read more