Geminoid DK An ultrarealistic android announced w Video

first_img Citation: Geminoid DK: An ultra-realistic android announced (w/ Video) (2011, March 7) retrieved 18 August 2019 from https://phys.org/news/2011-03-geminoid-dk-ultra-realistic-android-wvideo.html (PhysOrg.com) — The uncanny valley is getting smaller every day. For those of you not familiar with that concept, the uncanny valley is a term, first coined by researchers in Japan, that explains the innate human ability to know when a humanoid robot is just not human, a creepy feeling. A new generation of ultra-realistic robots may make these distinctions harder to make. Japan unveils humanoid robot that laughs and smiles (w/ Video) Mechnical test of Geminoid DK Geminoid DK is not the first attempt to make human-like robots, known as androids, that have created successful results. Another robot in the Geminoid family, the Geminoid-F is capable of mimicking human facial expressions and even laughing. Other bots, such as the HRP-4 have learned to mimic human expressions and sound while singing. Explore further More information: geminoid.dk/via IEEE (thanks Erico Guizzo for the tip) First test of the Geminoid DK. The bot will stay in Japan for a while, to finish testing with its human look-a-like, and then it will be shipped to Denmark to live in a special lab designed just for it. Hopefully, the right one gets the seat on the plane. The Geminoid DK will then be used to research “emotional affordances” in human-robot interaction, with a specific focus on looking at the cultural differences in human perception of robots. The latest robot in the family of ultra-realistic androids, called the Geminoid series, is so realistic that it can actually be mistaken for the person it was designed to look like. The new bot, dubbed the Geminoid DK, was was created by robotics firm Kokoro in Tokyo and is now being housed at Japan’s Advanced Telecommunications Research Institute International in Nara. The robot was designed to look like Associate Professor Henrik Scharfe of Aalborg University in Denmark. Why he wanted an exact robot duplicate of himself no one exactly knows, but the resemblance is uncanny. © 2010 PhysOrg.com This is from the first test of the Geminoid. The first hint of a smile triggers immediate response. 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

Statistical analysis could predict bankrupt stocks

first_img(Phys.org) — During the 20-year period from 1989 to 2008, 21% of of all stocks listed in US stock markets became bankrupt. Since bankruptcies affect many investors and have played a large role in the recent global financial crisis, predicting bankruptcy before it happens could help some investors avoid large losses. In a new study, a team of physicists has used concepts from statistical physics to identify some characteristic behaviors of pre-bankrupt stocks that differ significantly from stocks that don’t become bankrupt. The approach may eventually help investors forecast stock bankruptcies weeks or months in advance. Copyright 2012 Phys.Org 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. A second major difference between pre-bankrupt stocks and others is that the former experience a stronger correlation between volatility and volume. Previous research has shown that volatility and volume exhibit a positive correlation, meaning that large changes in stock price are often accompanied by large changes in trading volume. But during the 100 days preceding bankruptcy, a stock’s volatility and volume both tend to increase more than usual, and so the two become more strongly correlated than normal. So even without knowing the underlying causes of the increased volatility and volume, the strong correlation provides a statistical indication of approaching bankruptcy.The analysis uncovered another trend in the overall stock market during this 20-year period. When plotting the distribution of daily returns, the researchers grouped the results into four-year periods. During each four-year period, for both pre-bankrupt and non-pre-bankrupt stocks, the probability of having large returns decreased as time passed. This finding suggests that the entire stock market became progressively more mature and stable during this period.In the future, the physicists plan to further investigate these characteristic behaviors of stocks about to become bankrupt. They hope to develop a model that can precisely predict the time of bankruptcy, since the changes in stock behavior tend to increase closer to the day of bankruptcy. They also hope to gain insight into the underlying causes of the pre-bankrupt behavior identified here.“In principle, [this pre-bankrupt stock behavior] can be understood on the basis of human behavior in stock markets,” Huang said. “Due to the characteristic of self-interest, facing a ‘good’ stock or a ‘bad’ stock, the attitude of an investor is quite different, thus yielding distinct investing behavior. More details on the mechanism can only be revealed by comparing the present results with those obtained from agent-based modeling. This is a future project.” To do this, they analyzed the daily closing share prices and trading volume of all 20,092 stocks listed in US stock markets from January 1, 1989 to December 31, 2008. When defining stock bankruptcy as a stock with more than 100 days of trading records whose price drops more than 20% during the previous 100 trading days, 4,223 (21%) of all stocks became bankrupt during that period. (Somewhat surprisingly, nearly two-thirds [13,249] of all stocks disappeared from the market during this period due to delisting and mergers and acquisitions, in addition to bankruptcy.)The new statistical physics analysis uncovered several ways in which the behavior of stocks approaching bankruptcy differs from that of non-bankrupting stocks. One of the biggest differences is in the distribution of returns: pre-bankrupt stocks are more likely to have larger daily returns (both positive and negative) than stocks that don’t become bankrupt. In other words, pre-bankrupt stocks have larger day-to-day price fluctuations. As would be expected, the difference is bigger for negative returns than positive returns, indicating the falling stock price preceding a bankruptcy. The closer the day of bankruptcy approaches, the greater the possibility for these dramatic price changes. For all stocks, there is a correlation between volatility and volume. However, the closer a stock is to bankruptcy, the stronger the correlation, since both volatility and volume increase as bankruptcy approaches. Image credit: Qian Li, et al. More information: Qian Li, et al. “Statistical analysis of bankrupting and non-bankrupting stocks.” EPL, 98 (2012) 28005. DOI: 10.1209/0295-5075/98/28005 This figure shows the cumulative distribution function (CDF) for bankrupting and non-bankrupting stocks for each four-year period from 1989 to 2008 for (a) positive returns and (b) negative returns. Curves for bankrupting stocks are always more pronounced than for non-bankrupting stocks, indicating larger returns and higher volatility. As a side note, the probability of larger returns decreases for each four-year period, indicating greater overall market stability. Image credit: Qian Li, et al. center_img Investors who ‘gamble’ in the stock market have same characteristics as lottery players The physicists, from Boston University in Boston, Massachusetts, and Fudan University in Shanghai, China, have published their study in a recent issue of EPL.“On the basis of statistical analysis, we satisfactorily distinguish the evident difference between bankrupting and non-bankrupting stocks,” coauthor Jiping Huang of Fudan University told Phys.org. “This shows that it is possible to develop a statistical-analysis-based early warning system to forecast the time of bankruptcy. The system depends on stock prices, rather than corporate internal financial information.”For many decades, researchers and analysts have attempted to develop models for predicting corporate bankruptcy, but most of these models depend on the availability of detailed internal financial information about the corporation, which is often difficult to obtain. Here, the scientists have attempted to predict a corporation’s risk of bankruptcy by observing the market dynamics of its stock price. Citation: Statistical analysis could predict bankrupt stocks (2012, May 3) retrieved 18 August 2019 from https://phys.org/news/2012-05-statistical-analysis-bankrupt-stocks.html Explore further 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

Ricoh shows off omnidirectional camera w video

first_img © 2013 Phys.org “When viewing it like a regular panoramic image, you can also see up and down. When you pull out from the image, it finally becomes a circle, and you can also look at it as a sphere,” he commented.The fun elements of such spherical panoramic photos and their easy integration within creative displays are not lost on Ricoh’s creators. The camera is still in design phase; Asahina said not all of its features have been finalized. Although “the specs have not been decided yet,” the Ricoh team is discussing the project “with staff at art colleges,” he said. The technology, he added, could be presented as a “panorama ball” where the pictures are stuck onto the sphere. Japan’s Ricoh to buy Pentax digital camera brand More information: via Diginfo.tv 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 (Phys.org)—A novel panoramic camera from Ricoh is under development and it is described as a step beyond compact and single-lens reflex (SLRs) cameras. Takaharu Asahina of the New Business Development Center, Ricoh, told DigInfo TV about the company’s concept of an omnidirectional camera prototype. The camera shoots entire 360-degree panorama images with just one pass, just one click, and can then send them over to the user’s mobile device, such as tablet or phone, via Wi-Fi. The camera has two fish-eye lenses, each covering 180 degrees. Asahina said the Ricoh device can only take still photos, but its creators are interested in continuing the project to enable it to take video too. “We’d like to commercialize it, and make it a bit smaller. We want to keep developing it, so we can offer a version for consumers,” he said. Outside Ricoh, viewers seeing the design have used words like “wacky” and “curious” but are nonetheless impressed with its abilities. Citation: Ricoh shows off omnidirectional camera (w/ video) (2013, February 6) retrieved 18 August 2019 from https://phys.org/news/2013-02-ricoh-omnidirectional-camera-video.htmllast_img read more

Googles ADM phone finder coming this month

first_img Explore further 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. © 2013 Phys.org Huawei to launch first Windows 8 phone in US More information: officialandroid.blogspot.com/2 … ne-with-android.htmlcenter_img Android Device Manager will be available later this month for phones with Android 2.2 or later. The official Android blog carried the announcement last week in a posting by Android product manager, Benjamin Poiesz. The service will enable Android users to enjoy the same protective features that iPhone users enjoy with Apple’s Find my iPhone and that assorted third-party services offer those who have Android smartphones. Citation: Google’s ADM phone finder coming this month (2013, August 5) retrieved 18 August 2019 from https://phys.org/news/2013-08-google-adm-finder-month.html Lookout for Android, for example, has been a popular option thus far. The Lookout service carries a Lock It Down feature, where, If your device is in the wrong place at the wrong time, you remotely lock it to block access to your personal data. You can post a custom message to get it back, and there is the Wipe It Clean option to wipe data off the device if the user thinks the device is gone for good. You will not find any shortage of ‘Find My Phone’ services available. As for Apple, the Find my iPhone was announced back in 2010 as a software app to help pinpoint the exact location of an iOS device.Basically, the ADM phone finder covers all possible scenarios, for times when you accidentally drop your phone into a bag, or park it somewhere in the room where you cannot remember and need to hear it ring to locate the sound. What is nice about Android Device Manager is that even if your phone was in Silent mode the ADM will ring your phone at maximum volume. The second scenario is when you have forgotten your phone at some more remote location. The service will let you check its whereabouts on a map, If both scenarios don’t fit, and the phone is stolen, you have the option to wipe everything off the phone, erasing all data. Android Device Manager will be downloadable. Google says that you will need to be signed in to your Google account to use it. Several Android watching sites over the weekend, meanwhile, reported that the first stage of the ADM is being pushed out to a few users even though the service is not yet live. These users reported that the service was rolled out to their devices already. While it has taken Google some time to come out with its own find-phone solution, it can never be too late. Mobile security company Lookout viewed data last year and estimated that lost phones, if unrecovered, could cost U.S. consumers billions, They said at the time that “Losing your phone is more than just a hassle – it’s expensive. If everyone who misplaced their phone didn’t ever recover it, we estimate lost phones could cost U.S. consumers more than $30 billion in 2012.” Coffee shops, offices, bars and restaurants top the list as the most common venues to lose a phone in the U.S. The top U.S. city for lost phones is Philadelphia, and the most likely venue for losing a phone is a coffee shop. In London, they said, the top venue to lose a phone was a pub.last_img read more

Closer look at teeth suggests Columbian mammoth was actually a Eurasian steppe

first_imgThe steppe mammoth (Mammuthus trogontherii or Mammuthus armeniacus) Credit: Dmitry Bogdanov/Wikipedia Citation: Closer look at teeth suggests Columbian mammoth was actually a Eurasian steppe mammoth (2015, November 13) retrieved 18 August 2019 from https://phys.org/news/2015-11-closer-teeth-columbian-mammoth-eurasian.html © 2015 Phys.org Journal information: Science Explore further (Phys.org)—A pair of researchers became convinced over a period of years that the famed North American Columbian mammoth is actually the same creature as the Eurasian steppe mammoth (Mammuthus trogontherii)—it simply migrated over approximately a million and a half years ago. In their paper, by the now deceased Andrei Sher and his colleague Adrian Lister, published in the journal Science, the team suggests that worn teeth might be behind the mistaken belief that the Columbian mammoth was actually a descendant of the European mammoth, Mammuthus meridionalis.center_img Archeological evidence suggests that all mammoths got their start in Africa, approximately five million years ago—they subsequently migrated to Europe and then to Siberia and China. Along the way, those that made their home in Eurasia changed dramatically to allow for the colder climate—growing longer hair, for example and developing more complicated teeth to help with eating the different sorts of grasses—this led to them being labeled as more evolved by the science community. When mammoth teeth were found in many places across North America, it was assumed they had evolved from the European version of the mammoth, because the teeth appeared to be less evolved. But now, Lister contends, that thinking may be flawed. After thoroughly studying and comparing tooth fossils found in North America with those found in Eurasia, he has concluded that they are from one and the same animal. He suggests the reason for the confusion lies in the state of the teeth—most mammoth fossils found in North America, he notes, have been of older animals—animals whose teeth have lost some of their more complex features as they aged, making them seem to be similar to teeth from European mammoths.Lister suggests that some Steppe mammoths migrated to North America sometime between 1.5 and 2 million ago, by crossing the Bearing Strait, and evolved into what became the Columbian mammoth over many more years. He also suggests that European mammoths also migrated some time later, though they appear to have remained in the northern part of the continent, and likely mated with Columbian mammoths creating mixed offspring. A mammoth task — sorting out mammoth evolution More information: A. M. Lister et al. Evolution and dispersal of mammoths across the Northern Hemisphere, Science (2015). DOI: 10.1126/science.aac5660AbstractMammoths provide a detailed example of species origins and dispersal, but understanding has been impeded by taxonomic confusion, especially in North America. The Columbian mammoth Mammuthus columbi was thought to have evolved in North America from a more primitive Eurasian immigrant. The earliest American mammoths (1.5 million years ago), however, resemble the advanced Eurasian M. trogontherii that crossed the Bering land bridge around that time, giving rise directly to M. columbi. Woolly mammoth M. primigenius later evolved in Beringia and spread into Europe and North America, leading to a diversity of morphologies as it encountered endemic M. trogontherii and M. columbi, respectively. In North America, this included intermediates (“M. jeffersonii”), suggesting introgression of M. primigenius with M. columbi. The lineage illustrates the dynamic interplay of local adaptation, dispersal, and gene flow in the evolution of a widely distributed species complex. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Researchers test social contagion in laboratory setting

first_imgJudgment propagation down the chain. Observed intensity of social influence averaged over 20 experimental chains. The color coding indicates the influence of the originator’s judgment on the final estimates of all other individuals in the chain, as a function of their social distance from the originator (x axis) and the number of the round (y axis). Individuals located one degree of separation from the originator (i.e., social distance = 1) rapidly adopted the originator’s judgments (social influence approached 1 as early as round 2). Individuals located two degrees of separation from the originator were influenced by the originator after about 4 rounds of interaction. Participants located at a social distance greater than 3 were rarely influenced by the originator. Credit: arXiv:1704.01381 [physics.soc-ph] More information: Mehdi Moussaïd et al. Reach and speed of judgment propagation in the laboratory, Proceedings of the National Academy of Sciences (2017). DOI: 10.1073/pnas.1611998114 , On Arxiv: https://arxiv.org/abs/1704.01381AbstractIn recent years, a large body of research has demonstrated that judgments and behaviors can propagate from person to person. Phenomena as diverse as political mobilization, health practices, altruism, and emotional states exhibit similar dynamics of social contagion. The precise mechanisms of judgment propagation are not well understood, however, because it is difficult to control for confounding factors such as homophily or dynamic network structures. We introduce an experimental design that renders possible the stringent study of judgment propagation. In this design, experimental chains of individuals can revise their initial judgment in a visual perception task after observing a predecessor’s judgment. The positioning of a very good performer at the top of a chain created a performance gap, which triggered waves of judgment propagation down the chain. We evaluated the dynamics of judgment propagation experimentally. Despite strong social influence within pairs of individuals, the reach of judgment propagation across a chain rarely exceeded a social distance of three to four degrees of separation. Furthermore, computer simulations showed that the speed of judgment propagation decayed exponentially with the social distance from the source. We show that information distortion and the overweighting of other people’s errors are two individual-level mechanisms hindering judgment propagation at the scale of the chain. Our results contribute to the understanding of social-contagion processes, and our experimental method offers numerous new opportunities to study judgment propagation in the laboratory. It’s the thought that counts: The neuro-anatomical basis of forgiveness revealed (Phys.org)—Social contagion describes the propagation of beliefs, evaluations and attitudes through a network of people. It’s well understood that political beliefs, emotional attitudes and opinions are contagious within a network, but the precise mechanisms and dynamics are not well understood for two reasons: the complexity of network structures, and the behavioral processes that operate within the network. Explore further According to the three-degrees-of-influence hypothesis, judgement propagation is limited to a social distance of about three people—that is, an evaluative judgement typically will not spread beyond three degrees. Additionally, computer simulations demonstrate that the speed of judgement propagation decays exponentially with social distance from the source of the judgement. Researchers in Germany recently explored the mechanisms of evaluative judgement propagation through a social network. To determine the factors that influence or inhibit the transmission of a judgement, they designed a pair of experiments, and have reported their results in the Proceedings of the National Academy of Sciences.In the first experiment, they designed a visual perception task with three levels of difficulty, in which Subject A’s judgement and performance were repeatedly evaluated by Subject B. The researchers were interested in how repeated interactions between the subjects contributed to the contagion of a judgement.In the second experiment, they examined the collective dynamics of subjects with unidirectional chains of communication that extended to subjects C, D, E and F. All six participants repeatedly interacted with their predecessor, which allowed the researchers to gather data about reputation formation within a network and its resulting effect on the propagation of judgements.In accordance with the three-degrees hypothesis, the researchers found that judgements rarely propagated beyond three individuals; although they could spread farther, the time necessary to do so increased exponentially. Propagation over distances beyond three or four individuals required a consistently more accurate originator, absolutely error-free observation of others’ performance, and a network structure that remained static over several hundred interactions. These conditions are, needless to say, not easily replicated in the real world.The study found factors that impeded the propagation of judgements. Judgements become progressively more distorted over successive transmissions, even when individuals were able to observe the judgement and performance of another person. Judgements became less accurate, and thus less influential, the further they propagated from the source. Secondly, overweighting other people’s errors inhibited propagation. This is a common psychological phenomenon called “egocentric discounting,” well-known in literature. The problem arises because each performative error must be compensated with several good performances in order to restore reputation; this slows the transmission of judgement to the next subject. And for each step in the chain, the process repeats, leading to an exponential decay in transmission speed.The researchers suggest that further study could explore whether multiple sources of influence found in more complex networks could convey different judgements, thus contributing “noise” and impairing propagation; it is also possible that clustered networks with redundant ties could produce converging judgements along different pathways, providing social reinforcement to propagating judgements. Journal information: Proceedings of the National Academy of Sciences , arXiv 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: Researchers test ‘social contagion’ in laboratory setting (2017, April 14) retrieved 18 August 2019 from https://phys.org/news/2017-04-social-contagion-laboratory.html © 2017 Phys.orglast_img read more

South China Sea found to have heightened levels of anthropogenic surface nitrogen

first_imgCredit: Tiago Fioreze / Wikipedia © 2017 Phys.org Prior to the arrival of humans, nitrogen levels at or near the ocean surface were stable due to upward mixing of nitrate ions dissolving in deep water. That nitrogen was then consumed by phytoplankton and returned to the depths when they died. But humans have changed things by pumping nitrogen into the atmosphere by burning gasoline or coal and dropping it onto the ground to fertilize crops. Nitrogen makes its way to streams and rivers and eventually into the ocean. Computer models suggest the likelihood that human endeavors have led to doubling of ocean surface nitrogen levels, but because ocean water samples were not collected until recently, there has been no way to prove the models correct. In this new effort, the researchers sought to do so by measuring nitrogen isotopes in proteins captured in aragonite skeletons of banded coral collected from Dongsha Atoll in the South China Sea.The coral samples were dated and found to be on average 45 years old, and were also found to harbor the isotope 15N over time, which allowed for measuring the amount of nitrogen in the ocean over the years of their life. The researchers report that they found a decrease of 15N that allowed them to calculate the amount of nitrogen in the water—they found that nitrogen due to human impact now makes up approximately 20 percent of the nitrogen found in ocean surface water. The team then noted that by measuring the levels over time, it was clear that the increase was due more to atmospheric nitrogen sources (burning of fossil fuels) than fertilizer use. They report also that their measurements were sensitive enough to observe seasonal changes in nitrogen levels due to the inflow of fresh water during monsoon seasons. A battery prototype powered by atmospheric nitrogen (Phys.org)—A team of researchers from Taiwan and the U.S. has found evidence of higher levels of anthropogenic surface nitrogen in the South China Sea, likely due to an increase in atmospheric nitrogen levels. In their paper published in the journal Science, the group describes their study of nitrogen deposition on coral reefs over the past half-century. Edward Boyle with MIT offers a Perspective piece on the work done by the team in the same issue along with an outline of nitrogen ocean processes. More information: Haojia Ren et al. 21st-century rise in anthropogenic nitrogen deposition on a remote coral reef, Science (2017). DOI: 10.1126/science.aal3869AbstractWith the rapid rise in pollution-associated nitrogen inputs to the western Pacific, it has been suggested that even the open ocean has been affected. In a coral core from Dongsha Atoll, a remote coral reef ecosystem, we observe a decline in the 15N/14N of coral skeleton–bound organic matter, which signals increased deposition of anthropogenic atmospheric N on the open ocean and its incorporation into plankton and, in turn, the atoll corals. The first clear change occurred just before 2000 CE, decades later than predicted by other work. The amplitude of change suggests that, by 2010, anthropogenic atmospheric N deposition represented 20 ± 5% of the annual N input to the surface ocean in this region, which appears to be at the lower end of other estimates.center_img Explore further 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: South China Sea found to have heightened levels of anthropogenic surface nitrogen (2017, May 19) retrieved 18 August 2019 from https://phys.org/news/2017-05-south-china-sea-heightened-anthropogenic.html Journal information: Sciencelast_img read more

Optoacoustic microscopy at multiple discrete frequencies

first_img Journal information: Light: Science & Applications , Nature Methods To identify the characteristics of FD photoacoustic imaging, the scientists imaged a pair of crossed sutures in water at two wavelengths (488 nm and 808 nm) and discrete modulation frequencies. The superposition of various frequency contributions carried information of the imaged object (sutures). To extract information from more complex structures, Kellnberger et al. imaged the eye of 5-day-old wild-type Zebrafish lava ex vivo, using nine modulation frequencies spanning 10-50 MHz in 5-MHz steps. The scientists also compared the SNR (signal-to-noise ratio) between the FDOM method and conventional TD, which varied according to experimental parameters (laser energy, power employed and data acquisition hardware).Multifrequency amplitude and phase data could thus be processed for 3-D image reconstruction using a Fourier transform based on frequency-space representation (FSR) and time-space representation (TSR). Compared with TSR, the FSR based image reconstruction was computationally faster and did not require data inversion during image reconstruction. Explanation of frequency coding in dual wavelength FDOM. a) Simplified schematic of frequency coding on different wavelengths. Laser source 1 emitting at λ1 = 488 nm was loaded with the lowest modulation frequency f1, while laser source 2 emitting at λ2 = 808 nm was loaded with the highest modulation frequency fend. During imaging, we increased the modulation of wavelength λ1 and decreased the modulation frequency of λ2 in steps of fstep using odd numbers of modulation frequencies. b) Schematic representation of multiple modulation frequencies used for imaging, showing the superposition of frequencies at two wavelengths. Credit: Light: Science & Applications. Doi: https://doi.org/10.1038/s41377-018-0101-2   The scientists implemented the FDOM, operating in the frequency range of 5-50 MHz, as a hybrid system with multiphoton (MP) microscopy operating at 1043 nm. They then performed two-/three-dimensional imaging based on ultrasound amplitude and phase measurements at multiple frequencies. The amplitude and phase of the generated optoacoustic signals were resolved via demodulation in real time and recorded using an analog-to-digital converter. Due to high repetition rates, the FDOM achieved high signal-to-noise ratios (SNR), leading to the observed high-fidelity images. In total, the study examined the relationship between the modulation frequency, image fidelity and the signal-to-noise-ratio (SNR). Explore further 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. Optoacoustic imaging of microcirculatory blood flow in a mouse ear in vivo. a A scheme of the µDoppler detection set-up. FL1− flow 1 away from the US sensor, FL2− flow 2 away from the US sensor (FL2− < FL1−), FL1+ flow 1 toward the US sensor, IN flow direction into the chip, MC microfluidic chip, OL objective lens, P particles, US ultrasound, UT ultrasound transducer, fmod modulation frequency, OUT flow direction out of the chip. The close-up views illustrate the experimental detection of particles moving away from the ultrasound sensor, which is equivalent to a Doppler red shift. b-d Averaged frequency spectra acquired at flow speeds of 0 mm·s−1 (green), 0.3 mm·s−1 (red), or 1.3 mm·s−1 (red). The latter two flow speeds show respective red shifts of 2 Hz and 7 Hz from the modulation frequency because particles are flowing away from the transducer. e Doppler shifts measured from carbon particles as a function of the flow speed in a microfluidic chip. The black line shows a linear fit to the data. f A maximum intensity projection of a region of interest (ROI) of size 160 × 160 µm² in the mouse ear, which shows micro-vascularization. Scale bar, 30 µm. g A Doppler FDOM-flow map that was recorded in the same ROI, showing a peak amplitude of the recorded flow in the blood vessels. h, i A blend and an overlay of the Doppler flow map g and the optoacoustic image f, which show peak amplitudes as Doppler red and blue shifts relative to the transducer position. j An overlay of Doppler red- and blue-shift maps on the galvanometric scan in panel f. White arrows indicate the inferred directions of blood flow in various vessels. k A profile scan across a single capillary at the position indicated by the white arrows in the galvanometric scan in panel g. The red line represents a parabolic fit to the recorded Doppler shift data with a maximum blood flow speed of 0.44 mm·s−1. The gray solid curve shows the peak amplitudes at each measurement position. Credit: Light: Science & Applications. Doi: https://doi.org/10.1038/s41377-018-0101-2.   For FDOM-based in vivo tissue imaging, the scientists observed the ear of an anesthetized mouse. They obtained artifact-free images with multiple modulation frequencies that matched spatial frequencies of the imaged object. The scientists used a maximum of nine frequencies in the study. The SNR of the image increased from ~14 dB at a single frequency to ~30 dB at nine frequencies for sharper images.They then observed a mouse ear containing murine metastatic melanoma cells in vivo as before via synchronized excitation of two wavelengths (488 nm and 808 nm) at separate modulation frequencies. Using combined optoacoustic and optical microscopy, Kellnberger and co-workers were able to efficiently image the tissue features (i.e. vasculature, melanoma cells, collagen and keratinocytes) without conventional fluorescent tags or labels.Kellnberger et al. then performed FD micro-Doppler (µDoppler) measurements with the setup for the first time in a mouse ear for optoacoustic imaging of microcirculatory blood flow in vivo. Before conducting the intended measurements, the scientists used black carbon particles at varying flow rates of circulation in a microfluidic chip to validate the experimental setup. The µDoppler FDOM was employed to generate a map of microcirculation in a mouse ear thereafter. The microcirculatory blood flow revealed gradually increasing speed from the vessel edge to the core. Single-wavelength FDOM imaging of a suture and ex vivo Zebrafish samples. a) A schematic illustration of the scanning of two crossing sutures. b) Color-coded FDOM images of two 50-µm sutures, based on illumination at 488 nm and modulation frequencies of 10, 20, 30, and 40 MHz. The color frequency-space representation (FSR) superimposes the contributions by each modulation frequency. The grayscale FSR image based on four frequencies shows the final image. c) Cross-sectional profile of the dashed line shown in panel b, which compares the contrasts revealed by the various modulation frequencies. d) Ex vivo imaging of a zebrafish larva eyeball. The purple image was reconstructed using low (L) frequencies (10, 15, and 20 MHz); the green image using middle (M) frequencies (25, 30, and 35 MHz); and the red image using high (H) frequencies (40, 45, and 50 MHz). The color-coded overlay of all frequencies (FSR, 10 to 50 MHz) highlights the contribution of each spectral region. e) Orange color depicts the amplitude sum for the nine employed modulation frequencies. f) A bright-field image of a zebrafish eye, validating the fidelity of FDOM images. g) A comparison of the signal-to-noise ratios (SNRs) of images of two crossing sutures (40 µm diameter) obtained via FD and TD optoacoustic microscopy. The FDOM image yielded an SNR of ~35 dB. h) Under similar experimental settings, TD microscopy resulted in an SNR of ~29 dB. Credit: Light: Science & Applications. Doi: https://doi.org/10.1038/s41377-018-0101-2   In this way, the study demonstrated the use of frequency-domain optoacoustic microscopy (FDOM) based signal detection and demodulation for the first time. The scientists captured signals of amplitude and phase at multiple frequencies of the imaged object. The collective experimental setup contained inexpensive light sources, simultaneous multiwavelength illumination and direct Doppler-based flow measurements. In future studies, Kellnberger et al. will quantify the modulation frequencies, the imaging depth and increase the image resolution using an improved experimental setup. Optoacoustic imaging powered by short bursts of continuous wave (CW) lasers can stimulate the emission of ultrasound waves inside an animal or in human subjects. The method can noninvasively capture blood flow and produce 3-D images of cellular microarchitecture. Writing in Light: Science & Applications, Stephan Kellnberger and colleagues at the Institute of Biological and Medical Imaging, now report the possibility of obtaining high-fidelity optoacoustic images with cost-effective lasers controlled at multiple frequencies.center_img Thus far, optoacoustic imaging has only relied on techniques that detect signals in the time domain (TD) or those that only scan a single frequency at one or two wavelengths in the frequency domain (FD). The present study was a first to conduct in vivo optoacoustic imaging in an animal model via simultaneous illumination with two wavelengths. The scientists combined FDOM into a hybrid system to examine the relationship between image formation and frequency control. The use of discrete frequencies (a maximum of nine), allowed non-invasive optoacoustic Doppler shift measurements as flow observations in a microfluidic flow chamber in the lab first, and in tissue microvasculature in vivo thereafter. In the study, Kellnberger et al. used two CW diode lasers emitting light at 488 nm and 808 nm for illumination. More information: Stephan Kellnberger et al. Optoacoustic microscopy at multiple discrete frequencies, Light: Science & Applications (2018). DOI: 10.1038/s41377-018-0101-2 Sergey Telenkov et al. Frequency-domain photothermoacoustics: Alternative imaging modality of biological tissues, Journal of Applied Physics (2009). DOI: 10.1063/1.3116136 George J. Tserevelakis et al. Hybrid multiphoton and optoacoustic microscope, Optics Letters (2014). DOI: 10.1364/OL.39.001819 Vasilis Ntziachristos. Going deeper than microscopy: the optical imaging frontier in biology, Nature Methods (2010). DOI: 10.1038/nmeth.1483 In vivo skin imaging technology developed The authors experimentally demonstrated the multiple frequency-based, high-fidelity image generation of biological architecture by imaging fish and mouse tissue microvasculature. In the imaging experiments, they superimposed structural details that only appeared at specific frequencies of interest. The authors also non-invasively identified the speed of blood flow in tissue microvasculature by tracking the frequency shifts using the optoacoustic Doppler Effect. Optoacoustic (photoacoustic) sensing usually requires complex laser technologies. Such techniques can generate nanosecond length (1-100 ns), high-energy short photon pulses that conventionally illuminate transient (short-lived) energy in the time domain (TD). The ultra-short pulses can stimulate the emission of broadband ultrasonic waves, collected in the microsecond range to form optoacoustic images. However, complex laser technology can impose a low-pulse repetition frequency (PRF) and limit the number of wavelengths simultaneously available for spectral imaging. To avoid such limits, Kellnberger et al. developed frequency-domain optoacoustic microscopy (FDOM), in which light intensity can be controlled or modulated at multiple discrete frequencies using cost-effective hardware. Citation: Optoacoustic microscopy at multiple discrete frequencies (2019, January 9) retrieved 18 August 2019 from https://phys.org/news/2019-01-optoacoustic-microscopy-multiple-discrete-frequencies.html , Optics Letters © 2019 Science X Network Schematic representation of the hybrid microscopy system containing a subsystem for dual wavelength optoacoustic microscopy at 488 nm and 808 nm, co-aligned with a subsystem for multiphoton microscopy at 1043 nm. a) AMP amplifier, CCD bright-field camera, DAQ data acquisition card, DM dichroic mirror, GC galvanometric mirror controller, IQD IQ demodulator, LO1 local oscillator 1, LO2 local oscillator 2, NDF neutral density filters, OA optoacoustic, OF optical filter, PC personal computer, PH pinhole, PMT photomultiplier tube, SHG second-harmonic generation, THG third-harmonic generation, TPEF two-photon excitation fluorescence, xyz motorized stages. b) The spectrum of the excitation and detection wavelengths in hybrid FDOM/multiphoton (MP) imaging. c) Schematic comparison between time-domain (TD) optoacoustic microscopy, which uses short pulses of light, and frequency-domain (FD) optoacoustic microscopy, which is based on laser intensity modulated at multiple discrete frequencies. Credit: Light: Science & Applications. Doi: https://doi.org/10.1038/s41377-018-0101-2 , Journal of Applied Physics Single- and dual-wavelength FDOM imaging of a mouse ear in vivo. a) FDOM imaging at 488 nm. Cyan color represents the reconstructed image, from nine equally spaced frequencies in the range of 10 to 50 MHz. b–d) Individual images obtained at modulation frequencies of 10, 30, and 50 MHz, which depict the structures in the dashed box in panel a. e) SNR as a function of n frequencies that were used for FSR reconstruction. An asymptotic improvement is observed for n > 8 discrete frequencies. f) A profile view of the dashed box in panel a, which is delineated by a white dashed arrow. It demonstrates the relationship between modulation frequency and imaging resolution. Yellow crosses highlight the imaging resolution as a function of the modulation frequency: faster modulation (50 MHz) can clearly resolve small structures, even down to 4 µm, while slower modulation (10 MHz) cannot. g–l) Hybrid FDOM/multiphoton imaging of a mouse ear following the injection of melanoma cells. g) An overlay image that was obtained using four label-free microscopy modalities: FDOM at 488 nm and 808 nm, SHG at 522 nm, and THG at 348 nm. h) A bright-field image validating the results that were obtained via hybrid microscopy; MC, melanoma cells. i) FDOM imaging at 488 nm showing vasculature and melanoma cells. j) An FDOM image at 808 nm that shows B16F10 melanoma cells injected in the mouse ear. k) An SHG image showing the collagen distribution in the epidermis. l) A THG image that shows the tissue morphology; predominantly keratinocytes and hair follicles. Credit: Light: Science & Applications. Doi: https://doi.org/10.1038/s41377-018-0101-2  last_img read more

Keep it short silly

first_imgGet ready for a 10 minute dose of non-stop fun, as the theatre festival ‘Short and Sweet’ returns to the Capital this winter.  Delhi will be witnessing the third edition of world’s largest 10-minute theatre festival, which takes place in six countries. The festival started in Australia in 2003. Explaining the concept Short and Sweet, festival director Deepak Dhamija says: ‘This is the only platform where different theatre groups come together and perform plays. It is a unique concept to stage 10 minute plays because even in this time limit, it gives you the freedom to experiment. Various new forms of theatre will be explored during this festival which include clown theatre, Dastangoi and others.’ Also Read – ‘Playing Jojo was emotionally exhausting’The number of groups which are participating this year has gone up by 50 per cent. This year, around 40 groups and 100 participants will participate in the Delhi edition which will have nine shows spread over four weekends across four different venues. Theatre stalwarts like Sohaila Kapoor, Feisal Alkazi, Kuljeet Singh and Arvind Gaur will be directing pieces along with many others.’Our group will be performing the play Khol Do written by Saadat Hassan Manto, which is set in the Indo-Pak partition era. It was quite a challenge to encapsulate this play in 10 minutes especially with this subject, but we have tried our best. Thirty five actors form Asmita will be acting in this play,’ said Gaur.  Another theatre group participating is Dastangoi. Group founder-director Mahmood Farooqui has directed the play Also Read – Leslie doing new comedy special with NetflixDastan-e-mobile written by Ankit Chadha. ‘This is a Dastangoi presentation is on the usage of mobile phones and the problems and issues that a mobile consumer faces. Through this we have made an effort to explore the issues related to the mobile industry in India and how the consumer is exposed to problems in this system. We have also tried to probe the nexus between the carrier and operators and handset makers. It was quite a challenge to do it in 10 minutes but I thought it could be an experiment,’ said Chadha. Well, the results will be out soon.DETAILAt: India Habitat Centre, Kamani Auditorium, LTG Auditorium and Epicentre (Gurgaon)When: 22 November to 14 December Timings: 7.30 pmlast_img read more

Theatre festival by children for children

first_imgThe festival, Bal Sangam 2013, held every alternate year and currently in its eighth edition is organised by the Sanskar Rang Toli (theatre-in-company) of the NSD with the aim of imparting education to children about the country’s traditional arts.While the event includes folk dance, martial arts, acrobats, street performance and many more experiences, this year organisers say there is a special focus on the North East region.’The North East region has very rich traditional and cultural heritage. Various art forms are so rare and exquisite it has become the need of the hour that they be brought back into the limelight and be given due attention they so right fully deserve,’ Ratan Thiyam, National school of Drama, Chairperson said. Also Read – ‘Playing Jojo was emotionally exhausting’NSD plans to introduce drama therapy to help physically and mentally challenged children. The therapy, organisers say, will help them regain their confidence and will give them a platform to perform.’Theatre education helps a child to become more expressive and leads to overall personality development. This also makes them sensitive towards people and the society too. We are trying to work taking theatre in education to all states in the country,’ said Waman Kendre, Director, NSD.’Bal Sangam should be able to get an international platform and there should be a proper training program for teacher’s training in the field of theatre. This will help to bring more and more people to theatre,’ he said.The festival will include a street performance and traditional folk theatre performance groups.WHEN: 14 November onwards WHERE: National School of Dramalast_img read more