Researchers develop net nanodetector

center_img © 2010 PhysOrg.com Low levels of formaldehyde in clothing unlikely to pose health risk Citation: Researchers develop “net” nanodetector (2011, August 1) retrieved 18 August 2019 from https://phys.org/news/2011-08-net-nanodetector.htmllast_img read more

Team Prosecco dismantles security tokens

first_img Citation: Team Prosecco dismantles security tokens (2012, June 27) retrieved 18 August 2019 from https://phys.org/news/2012-06-team-prosecco-dismantles-tokens.html RSA SecurID Expands Support for Mobile Platforms Explore further RSA SecurID SID800 Authenticator Token (Phys.org) — As password systems alone prove inadequate to protect information on computers against hackers, security customers have taken the advice of vendors to step up to tokens, those online security credentials that add an extra layer of protection at login. The token is designed to generate a six-digit security code that is unique to the person’s credential. The rise of two-factor authentication has been accepted as the way to go for governments and corporations trying to bolster their information security. This week, though, leading token vendors are hearing news they can do without. center_img © 2012 Phys.Org An international team of computer scientists figured out how to extract the keys from RSA’s SecurID 800 model in as few as thirteen minutes. The token heists were performed by a group calling themselves Team Prosecco. If they could figure the way to break in so quickly, then that places troubling questions about the efficiency of cryptographic keys being used to log into sensitive corporate and government networks, the kinds of keys stored on “hardened” security devices used by governments and businesses. One argument often heard among security vendors defending their token systems is that attempts, though possible, would take so long and be so difficult that risks are minimal.The team reports that their token attack also works against older versions of the Estonian national ID card. In the case of the Estonians ID system, they were able to figure out how to forge a digital signature in about 48 hours.Their method consisted of both modifying and improving the “Bleichenbacher” attack on RSA PKCS#1v1.5 padding.Bleichenbacher’s padding oracle attack was published in 1998. The method they use is called the “padding oracle attack.” It involves slightly modifying encrypted text thousands of times. If the system views the extra padding as a valid encryption, the attacker learns something about the original text until eventually the whole thing becomes known. As the researchers report, “We show how to exploit the encrypted key import functions of a variety of different cryptographic devices to reveal the imported key. The attacks are padding oracle attacks, where error messages resulting from incorrectly padded plaintexts are used as aside channel.”When the oracle (server) responds, it leaks data that may allow attackers to decrypt messages without knowing the encryption key. The team has refined the method to the point where the number of calls is significantly reduced to reveal the key. The attack also works against other widely used security tokens than just that one particular model, SecurID 800, from RSA. All of the companies involved were notified before the paper was published, says the research team.RSA’s SecurID 800 model took the shortest time to open at thirteen minutes. A device model made by Siemens took 22 minutes. A device model made by Netherlands-based Gemalto took 92 minutes. The researchers will be describing their successful exploits in a paper presented at the CRYPTO 2012 (the 32nd International Cryptology Conference) in Santa Barbara, California, in August. The accepted paper is titled “Efficient Padding Oracle Attacks on Cryptographic Hardware.” The document is an Inria (the French National Computer Science Research Institute) study.Not all security watchers, however, are convinced that the study is useful. An RSA blog posting, written by Sam Curry, said “Don’t believe everything you read,” and that “Your SecurID Token is Not Cracked.” He went on to say that “This is not a useful attack. The researchers engaged in an academic exercise to point out a specific vulnerability in the protocol, but an attack requires access to the RSA SecurID 800 smartcard (for example, inserted into a compromised machine) and the user’s smartcard PIN. If the attacker has the smart card and PIN, there is no need to perform any attack, so this research adds little additional value as a security finding.” 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

MIT group shows unseen motion captured in video

first_img © 2013 Phys.org More information: people.csail.mit.edu/mrub/papers/vidmag.pdfweb.mit.edu/newsoffice/2013/cs … visible-changes.html Citation: MIT group shows unseen motion captured in video (2013, March 1) retrieved 18 August 2019 from https://phys.org/news/2013-03-mit-group-unseen-motion-captured.html Explore further The process is called Eulerian Video Magnification. “Our method, which we call Eulerian Video Magnification, takes a standard video sequence as input, and applies spatial decomposition, followed by temporal filtering to the frames. The resulting signal is then amplified to reveal hidden information,” they wrote. They noted that their technique can run in realtime to show phenomena occurring at the temporal frequencies selected by the user.”We are inspired by the Eulerian perspective,” according to the scientists, “where properties of a voxel of fluid, such as pressure and velocity, evolve over time, in a spatially multiscale manner.” In their approach to motion magnification, they said they do not explicitly estimate motion but rather exaggerate motion by amplifying temporal color changes at fixed positions. 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) —A baby lies in the crib looking motionless, a typical situation causing worry to new parents, wondering if the baby is still breathing. A video run through an algorithm designed for amplification shows the baby is indeed breathing with movements that were invisible to the naked eye. It’s that special algorithm at the heart of interest in the work of a group of scientists at MIT who work on a project called motion magnification. They have said that “Our goal is to reveal temporal variations in videos that are difficult or impossible to see with the naked eye.” Their process breaks apart the visual elements of every frame of a video, reconstructed with an algorithm tool that can amplify aspects of the video. This is not the first time their advances have been publicized. The program was presented last year at the annual computer graphics conference, Siggraph. What is new is that the team has revamped the work and they posted code online for people interested in exploring such renderings of motion that otherwise would not be detected by the naked eye. “Our team is still actively working on this direction, so people can expect more to come,” said a team member. “We hope that it will motivate people to look deeper into this type of processing and different applications it can support.” Researchers amplify variations in video, making the invisible visible The team from MIT’s Computer Science and Artificial Intelligence Laboratory are working on the program to analyze videos to pick up movements. The program was first developed essentially to monitor neonatal babies. They believe their algorithm can be applied to other scenarios to reveal changes imperceptible to the naked eye as well, as in hospital monitoring of patients. You can see a person’s face flushing as the blood pumps from his heart. You can read a baby’s pulse. A spatial pattern of when the blood goes and where is seen; scientists could look to see where the blood flows on the body as well as on the face. “There is a big world of small motions out there,” said a team member. Overview of the Eulerian video magnification framework. Credit: Hao-Yu Wu et al.last_img read more

Harmonic holograms Highspeed threedimensional imaging captures biological dynamics

first_img PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Moving forward, says Bartels, the team is working to develop and integrate other methods of high-speed 3D imaging into their SHG holography platform – specifically, 3D fluorescent imaging capabilities, which is more challenging because fluorescent light lacks the coherence that we are able to exploit for high speed SHG 3D imaging. “We’re primarily interested in studying fast dynamics in live biological tissues and systems, and are working with a number of collaborators to look at various systems that display native SHG emission. We’re also expanding the capabilities of the microscope to increase axial resolution through new hologram reconstruction algorithms and modifications of the microscope design.” Their goal is to study dynamics that have been too fast to be captured by current microscopy tools and better understand that relevant biological processes. High-speed 4D reconstructions with centroid tracking. (A) 3D reconstructions of potato starch granules with a trace marking the centroid path. Yellow indicates t = 0 ms, orange indicates t = 32 ms, and red indicates t = 63 ms. (B) 3D volume reconstructions show movement in three dimensions. Yellow indicates t = 0 ms, orange indicates t = 50 ms, and red indicates t = 92 ms. (Scale bars: 10 μm.) (A video recording of the moving particles is provided in Movie S1.) Copyright © PNAS, doi:10.1073/pnas.1306856110 Holograms set for greatness Bartels tells Phys.org that while laser scanning is the standard approach to imaging with nonlinear optical contrast, since the beams must be scanned 3D image update rates are limited – and the capture of fast dynamics are restricted to 1D or 2D images, or charting a trajectory through the specimen. “A major problem is that live specimen motion provides changes to the image that distort measurements and make it impossible to track high speed behaviors. On the other hand, SHG holography is a non-scanning technique that captures 3D information in a single shot for each volume image frame.”Bartels adds that in addition to neural circuit dynamics, the scientists are interested in observing the high speed dynamics of muscle contraction and connective tissues subjected to high speed stresses, and observing the resultant strains. “Current imaging techniques lack the ability to observe the effect of such trauma on tissues, as well as to follow the subsequent strains and relaxation or damage that occurs. SHG holography will be able to capture a time sequence of images from these tissues to better understand tissue properties. Moreover,” he continues, “SHG holography opens up imaging of dynamics that were previously not observable. As biological functions are determined by 3D organization in tissues, the ability to study high speed dynamics of biological functions – or the response of biological systems and tissues to rapid external stimuli, perturbations, or trauma – will expand our understanding of the biology, and may inform our ability to treat injuries.” © 2013 Phys.org. All rights reserved. Citation: Harmonic holograms: High-speed three-dimensional imaging captures biological dynamics (2013, November 28) retrieved 18 August 2019 from https://phys.org/news/2013-11-harmonic-holograms-high-speed-three-dimensional-imaging.html Given these challenges, Bartels says that increasing imaging speed required us to understand how to optimize the signal to noise levels of the SHG hologram and balance that optimization with an experimental design that prevented holographic fringes from washing out during high speed object motion. “We developed rigorous metrics for independently estimating noise and signal levels of a hologram, and optimized image speed, sensitivity, and signal to noise levels to obtain the optimal performance from the experimental system.” Their results suggested improvements that they plan to implement in their next-generation system. Comparison of SHG holographic reconstructions with LSM 3D images. All images were taken from a 50-μm thick slice of mouse skeletal muscle. (A) Holographic reconstruction shows connective tissue and sarcomere structures. (B) LSM 3D image of the same tissue region. (C) Volumetric overlay of the 3D images in A and B. (Scale bars: 10 μm.) Another volume reconstruction comparison is provided in SI Methods, section 13, Fig. S7. Copyright © PNAS, doi:10.1073/pnas.1306856110 Schematics of the SHG holographic microscope. (A) Off-axis holography setup is configured as a modified Mach–Zehnder interferometer. A detailed description is provided in Methods. (B) Representation of a sample emitting SHG, which is combined with the reference on a high-speed camera. (C) Holograms are numerically reconstructed, forming video-rate 3D information from a 2D hologram image. Copyright © PNAS, doi:10.1073/pnas.1306856110 “Beyond biological applications,” Bartels concludes, “I can imagine high throughput imaging of starch content for studying or monitoring biofuel production. Alternatively, kinetics of crystal formation and growth for some classes of crystals, including protein crystals, could be monitored.” (Phys.org) —In the world of biomedical science, optical microscopy rules – and nonlinear optical microscopy, which uses ultrashort pulse lasers as the illumination source, allows researchers to glean much greater detail from biological specimens. That being said, the technique’s weak signal levels significantly limit 3D image acquisition rates. Recently, however, scientists at Colorado State University employed 3D second harmonic generation achieved frame rates over 8,000 times faster than is possible with current nonlinear optical microscopy. (In second harmonic generation, or SHG, photons interact with a nonlinear material to form new photons with twice the energy and, therefore, twice the frequency and half the wavelength. While conventional optical microscopes obtain contrast by detecting variations in optical density, path length, or refractive index of the specimen, a second harmonic imaging microscope derives contrast from variations in a specimen’s ability to generate second harmonic light from incident laser light.) Moreover, the scientists introduced new methods that greatly improve the ability to quantify signal-to-noise quality. The researchers state that their study allows nonlinear optical imaging to study behavior that current experimental methodologies are unable to capture, such as neural circuit dynamics. 3D reconstructions of 350-μm thick mouse skeletal muscle at depths up to 150 μm. With the focus on the surface of the tissue as indicated in the cartoon, an SHG hologram is recorded (A) and reconstructed 75 μm deep into the tissue (B), 100 μm deep into the tissue (C), and 150 μm deep into the tissue (D). Holograms were recorded with an exposure time of 1 ms (A–C) or 4 ms (D). (Scale bars: 10 μm.) Copyright © PNAS, doi:10.1073/pnas.1306856110 Journal information: Proceedings of the National Academy of Sciences Play 3D SHG video recording of a potato starch flow recorded at 1,594.6 fps. (Scale bar: 10 μm.) Copyright © PNAS, doi:10.1073/pnas.1306856110 The main challenges in observing dynamics in live tissue, Bartels says, are the same as needed to speed up imaging to 10 mm/s – namely, brighter SHG scattering (which for a given specimen can only be increased by decreasing the illumination pulse duration) and optimizing the detection geometry. “While in this study we used a bulk ytterbium (Yb) solid state laser built in my laboratory that makes 350 femtoseconds laser pulses, we’re rebuilding the microscope with a new laser source that generates 80 fs pulses. This should increase our signals and top-end image field velocity by more than a factor of four. Also, it’s important to move the camera plane as close to the object as possible,” he points out, “as long as the fringes aren’t degraded by the moving objects.” The current paper provides a framework for evaluating an optimal experimental setup. Comparison of SHG holographic reconstructions with LSM 3D images. All images were taken from a 50-μm thick slice of mouse skeletal muscle. (A) Holographic reconstruction of collagen-rich connective tissue found in the skeletal muscle slice. (B) LSM 3D image of the same tissue region. (C) Volumetric overlay of the 3D images in A and B. (Scale bars: 10 μm.) Copyright © PNAS, doi:10.1073/pnas.1306856110 Explore further More information: Submillisecond second harmonic holographic imaging of biological specimens in three dimensions, PNAS November 12, 2013 vol. 110 no. 46 18391-18396, doi:10.1073/pnas.1306856110 The scientists have also been able to exploit coherent scattering of second harmonic light from an entire specimen volume. “We’ve already observed the benefits of coherent volume scattering by comparing images captured with SHG holography and more conventional laser scanning second harmonic holography,” Bartels notes. “In structures, such as sarcomere segments in muscle fibers, we observed significantly brighter SHG signals from holography as compared to laser scanning SHG microscopy.” He adds that the differences were less pronounced for more compact objects. Prof. Randy A. Bartels discussed the paper that he, David R. Smith and David G. Winters published recently in Proceedings of the National Academy of Sciences. “Our current configuration is capable of imaging continuously at essentially 10 mm/s for bright enough objects,” Bartels tells Phys.org. “In general, the main challenge in achieving this is making sure that the fringes don’t wash out for a given velocity – and we provide theory to easily calculate these conditions, such that the configuration in this paper was capable of recording holograms of objects moving at this velocity. If we consider an object moving at 10 mm/s,” he explains, “then in a 1-ms integration time (which we can easily do continuously), we need to resolve an object displacement of ~ 10 micron, which is roughly twenty times our current imaging resolution.” Although faster imaging is possible for a bright enough object with the camera plane moved farther away from the image plane, he adds, the object scatter enough second harmonic light to form a good hologram – and while for any particular object this is limited by the hyperpolarizability of constituent harmonophores (molecules or particles that produce second harmonic generation), the researchers can increase brightness with shorter illumination pulses.”We’re already using SHG to observe endogenous harmonophores,” Bartels continues, and are now studying live dynamics of a number of processes such as muscle contractions in embryonic models, and dynamics of structural tissues such as tendons, under high strain rates.” The team is also taking beginning steps to image action potentials of neurons. 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

Make it a childs play

first_imgThis is the silver jubliee year of NSD’s Sanskar Rangoli.Children across the country will come to the national capital to participate in the event.  They will present folk performing arts from North East and folk theatre from across the country.The week long event will witness various folk and traditional performances like Lav Kusha, Darz-E-Paather, Gosian Pathe, Mahishashur Mardini and  Maach. Each day all the groups invited will give their performances as well as a special performance will be lined up for later part of the evening.First three days will see art and folk performances by children practicing these arts from different regions of the country. Evenings will  feature a mythological tale in like Bali Wadh and Dwapar Lila,  Rass Leela, Yakshagana Dance Drama among others.Around 2 lakh people, mostly children, have witnessed Bal Sangam till date in the last 7 Bal Sangams. Around 85 groups have participated and showcased around 672 performances till date.last_img read more

The arts eye view

first_imgAs June wraps up, here is something for the Delhi art lovers. Panorama-3, curated by Priyanka Banerjee, brings to you a group exhibition that identifies strong new talent and bringing great art to a wide audience. The platform provides artists from around the city to exhibit and showcase their work.Banerjee, an energetic art curator, recognises the efforts of emerging artists by promoting their creative talent. She identifies talented young artists and provides them a platform to showcase their creativity. To continue with the spirit of art-appreciation, she is all set to present her next exhibition that features more than thirty artists – the best and brightest in the city. Also Read – ‘Playing Jojo was emotionally exhausting’With a renewed impetus to excellence, this exhibition aims at sustaining the artistic aspirations of the city by offering a holistic cultural experience. Banerjee believes that just the way a panorama represents an entire worldview of a place, this exhibition is a world view of the thoughts of its many diverse yet like-minded artists. These artworks emote through vivid strokes – some are muted and some vibrant; together they create a surreal experience for art aficionados. Interestingly, it is the theme of spirituality that sets this event apart from others. Also Read – Leslie doing new comedy special with NetflixMridul Chakraborty, Uma Bardhan, Kashi Nath Bose, Ganesh Panda, Hamlet Shougrakpam, Nilay Sircar, Rajeev Semwal, Meghna Agarwal, Sahil Jain, Saru Sharma, Rohini Jain, Jaya Sharma, Harpal Singh, Lalit Mohan, Shalini Varshney, Amit Kumar, Abid Zaidi,  Sadaf Khan, Seema Kashyap, Shalini Goyal, Roshi Goyal, Aakanksha Bagga, Tarini Ahuja, Tatini Sengupta, Viniitii Vasundhara Aggarwal, Alpana Kataria, Jasmeet Khurana, Shipra Gupta, Darshan Sharma, Ekta Gandhi, Mahender Rai are some of the participants among others. Chakraborty has tried to depict speed in the lives of human beings. Jain’s paintings portray pigeons both symbolically and in abstract forms. Bardhan is fascinated by figurative paintings and observes his subjects for weeks, months and even years before bringing them alive on canvas. Meghna Agarwal uses a variety of mediums to express ideas like power and permanence through her works. Saru Sharma talks about the human desire to attain joy through her works and attempts to highlight the relation between our daily actions and attainment of pleasure through them.While each artist brings the best to the canvas, the real reason we want you to attend this exhibition is that it is one of its kind event that is funded by the artists entirely on their own. All this for the pure love of art.last_img read more

Interactive art

first_imgOrganised by Think Arts, the 26-day event will take children on a sensorial journey through an interactive art and theatre exhibition.NM Director-General Sanjiv Mittal said, “The exhibition aims to supply back the luxury that Indians a generation ago enjoyed in their younger days. We have scheduled it with the summer vacations for schools upcountry.”Ruchira Das, founder of Think Arts, says, “Elements would enable the participant children to a world of wonder — in all of its senses.” Also Read – ‘Playing Jojo was emotionally exhausting’ “We had the outdoors to play in. We touch, smell, feel, hear, use all of our senses as we explore. These experiences fuel our imagination and heightened our sense of perception,” she added.“At Elements, every action of the child changes the experience for those who follow, creating an ever-evolving space”, reveals Das, who has conceptualised the show.The show will have a room of cupboards and drawers featuring a drawer of tastes, smell, sounds, miniatures among others. “The only way to get to the next room (labyrinth) is by entering a cupboard. The labyrinth has a jigsaw puzzle inspired by a miniature from the gallery at the National Museum,”added Das. Also Read – Leslie doing new comedy special with NetflixThere is also an art room that invites children to engage in building a sculpture using cardboard boxes, scraps of cloth, paper and found objects. With every interaction, the sculpture takes a new form.Another feature is the textured path, along which the children walk on sand, pebbles, foam and sawdust among others. There is also a music room which has easy-to-play instruments that will help the child explore the sounds of different musical sounds made from elements like seeds, metal, wood and bamboo. Many of these instruments are inspired from those in the music gallery at the National Museum.“The team behind Elements comprises several artistes and organisations who basically believe that children are “thinking, feeling beings who are capable of as much, if not more depth, and understanding as an adult”, says Anurupa Roy, from Katkatha Puppet Arts Trust. She along with Shravan Heggudu and S Raghuvendra, are the designers of the exhibition and co-creators of the artworks.The team also includes professional musician Rajat Mallick and Prarthana Hazra, a recent post-graduate from Kala Bhavan, Santiniketan.When: June 10 – July 5Where: National Museumlast_img read more

Zitar inventor Niladri Kumar forays into EDM

first_imgHe’s widely heralded as the inventor of the ‘zitar’ — a combination of sitar and guitar — and stands among one of the leading exponents of Indian classical music. But now Niladri Kumar, who is ‘very intrigued’ with electronic dance music (EDM), is cutting out an EP based on the popular genre.Niladri, whose new single Head to the heart, which also features Bollywood singer and guitarist Rashid Ali, was unveiled earlier this month, says he is working on two different albums. And one of these would mark his foray into the uncharted musical territory of EDM.  Also Read – ‘Playing Jojo was emotionally exhausting’“There are a couple of albums under the pipeline. There are two different albums. One album is deeply rooted in the Indian classical tradition, but it will be on the zitar. It is basically all about the hardcore compositions which we have in Indian classical music, but it will be rendered in a way never done before,” Niladri said over phone from Mumbai. “The second album I am trying to do will be based on EDM. I am very intrigued with EDM and how young people connect to the EDM grooves and music. So I always wanted to do something on those lines. Maybe I’ll release an EP containing around five tracks this year,” he added.  Also Read – Leslie doing new comedy special with NetflixEven as Indian classical musicians have often worked with fusion overtones, a sitar player working on an EDM-based album is something quite unheard of. About this unconventional musical experiment, Niladri said: “The fusion space is a little blurred. A lot of things come into the fusion space and it is not clearly demarcated. The EDM space is somehow slightly more demarcated than fusion now. I want to work with that space and add to the melodic element in the EDM genre.”  Besides, he feels “you have to try and give the fans a new story, a new thought”.However, Niladri’s ‘ulterior motive’ behind doing this album is to “get to people who connect to the EDM space and are totally unaware of the huge melodic content that our Indian classical instruments hold and how well it can enhance the EDM space”.Niladri, who was first exposed to EDM in Britain, says although he is not very well-versed with Indian EDM producers, he thinks “there is good potential with what’s happening in here”.“When I heard the young kids going for it here, I thought it’s maybe a great idea to use that genre and try and portray your melody in there and give them a feel of the sitar, zitar and the whole Indian space, but not too much,” he added.As far as traditional Indian classical music is concerned, Niladri believes that “Indian classical music is something which has stood the test of centuries, amid the invasion of genres and sounds”.“There are more sitar, tabla and sarod players than any other time in history. That proportion had not increased in terms of the audience listening to it. It’s about the depth in it. There’s a big science involved it,” he said. “People should stop asking about the future of Indian classical music. The question should be asked, what is the future of EDM and fusion music,” added the musician, who will launch his new brand ‘STAY UP Rooted’, and will perform for a cause at a concert in Mumbai on October 30.last_img read more