Gravity might amplify quantum fluctuations create astrophysical objects

first_img © 2010 PhysOrg.com (PhysOrg.com) — In a new study, physicists have proposed that gravity could trigger a runaway effect in quantum fluctuations, causing them to grow so large that the quantum field’s vacuum energy density could dominate its classical energy density. This vacuum-dominance effect, which emerges under some specific but reasonable conditions, contrasts with the widely held belief that the influence of gravity on quantum phenomena should be small and subdominant. Digital Quantum Battery Could Boost Energy Density Tenfold Daniel Vanzella and William Lima of the University of São Paulo in Brazil have suggested the new idea in a study published in a recent issue of Physical Review Letters. The concept is based on the idea that virtual particles are continually popping into and out of existence in empty space. Vanzella and Lima propose that a powerful gravitational field – such as one that exists near a neutron star – could create a region of many virtual particles densely packed together. The energy density of the virtual particles might grow to become even larger than the energy of the neutron star, or other object that generated the gravitational field. At this size, the vacuum energy of the quantum field could possibly influence astrophysical processes. For example, it could play a role in the collapse of neutron stars which would lead to the formation of black holes, or in structure formation during cosmological expansion.If the vacuum-dominance effect exists and is strong enough to have such consequences, scientists will still have to discover a new kind of quantum field that would react to gravity in this way, since none of the quantum fields based on known forces could induce these effects. Still, the physicists note that the possibility of vacuum dominance itself is surprising to discover within “a simple and classically well-behaved situation.” 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 Citation: Gravity might amplify quantum fluctuations, create astrophysical objects (2010, May 17) retrieved 18 August 2019 from https://phys.org/news/2010-05-gravity-amplify-quantum-fluctuations-astrophysical.html More information: Daniel Vanzella and William Lima. “Gravity-Induced Vacuum Dominance.” Phys. Rev. Lett. 104, 161102 (2010). Doi: 10.1103/PhysRevLett.104.161102. Explore furtherlast_img read more

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Web abuzz with claims that Hubble sought to censor Lemaitres paper

first_imgEdwin Hubble (PhysOrg.com) — In one of those odd scientific debates where people who ought to know better, speak up, and in this case, print articles on arXiv, making claims about personal issues rather than science, buzz has been created that might lead to little more than rhetoric. In this case, it’s first Sidney van den Bergh, a Canadian astronomer, who has published a paper on arXiv citing evidence that Belgian astronomer Georges Lemaitre’s paper on cosmological observations appeared to have been intentionally censored when translated into English, and then David Block, a South African mathematician and amateur historian adding fuel to the fire by publishing to the same site an article where he asserts he has proof that American, Edwin Hubble (of whom the Hubble telescope is named) was involved in a conspiracy of sorts, to censor the paper previously mentioned by van den Bergh. Block offers as proof, a letter written by Scottish astronomer William Marshall Smart (editor for MNRAS), that he says, shows that it was Lemaitre himself who performed the translation, but because Smart only asked for certain sections to be translated, the end result wound up an abbreviated version of the original. Block then goes on to say he believes it was pressure on Smart, from Hubble, that caused him to do what he did, though he offers little evidence to support such a claim.At this point, professional historians are not convinced, and so, this argument, as with many others of its kind in the science field, will likely rage on, with little gained, but perhaps something lost, as energy that could be spent on science, is wasted on meaningless squabble. © 2010 PhysOrg.com Zeroing in on Hubble’s constant Georges Lemaitre The entire argument centers on a paper first published by Lemaitre in 1927 in Belgium; written in French it wasn’t read much outside of his home country. In the paper, Lemaitre outlined his theory that the universe appeared to be expanding, and also offered a constant that could be used to determine the rate. In 1929, Hubble published a paper that offered the same theory and constant (which came to be known as the Hubble constant) and was at the time given full credit for the discovery. Later however (1931), Lemaitre’s paper was translated into English and published in the Monthly Notices of the Royal Astronomical Society (MNRAS), which of course gave some credence to Lemaitre’s work, but not entirely, because it was subsequently discovered that certain sections of the original paper had been omitted, the most important of which, was the part where Lemaitre derived the constant for which Hubble was ultimately credited. Citation: Web abuzz with claims that Hubble sought to censor Lemaitre’s paper (2011, July 13) retrieved 18 August 2019 from https://phys.org/news/2011-07-web-abuzz-hubble-sought-censor.html 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. More information: A Hubble Eclipse: Lemaitre and Censorship, David L. Block, arXiv:1106.3928v2 [physics.hist-ph] arxiv.org/abs/1106.3928v2AbstractOne of the greatest discoveries of modern times is that of the expanding Universe, almost invariably attributed to Hubble (1929). What is not widely known is that the original treatise by Lemaitre (1927) contained a rich fusion of both theory and of observation. The French paper was meticulously censored when printed in English – all discussions of radial velocities and distances (and the very first empirical determination of “H”) were omitted. Fascinating insights are gleaned from a letter recently found in the Lema^itre archives. An appeal is made for a Lemaitre Telescope, to honour the discoverer of the expanding universe.via Nature Explore furtherlast_img read more

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Researchers discover how bacteria can immobilize uranium

first_img Explore further © 2011 PhysOrg.com (PhysOrg.com) — For several years, researchers have known that certain kinds of bacteria are able to “feed” off certain metals by either adding or removing electrons from their structure, but until now, haven’t really understood how they do it. Now, new research by Gemma Reguera and her team at Michigan State University have shown that the bacteria do so by means of protein nanowires, called pili, which are hair-like appendages with electrical conductivity. They have reported their findings in the Proceedings of the National Academy of Sciences. More information: Extracellular reduction of uranium via Geobacter conductive pili as a protective cellular mechanism, Cologgi, et al. Proceedings of the National Academy of Sciences, 2011. dx.doi.org/10.1073/pnas.1108616108 Making more efficient fuel cellscenter_img Citation: Researchers discover how bacteria can immobilize uranium (2011, September 6) retrieved 18 August 2019 from https://phys.org/news/2011-09-bacteria-immobilize-uranium.html The team specifically set out to find out how a specific type of bacterium known as a Geobacter, in this case, G. sulfurreducens, are able to clean up nuclear waste left behind by the cold war in such places as Colorado mines. They, like other researchers, believed that the bacteria were able to do its work through use of pili. In order to find out for sure, they had to induce the specimens to actually grow some in the lab, something that had stumped others before them. To force them, Reguera and her team subjected G. sulfurreducens, to much more harsh conditions than had been done before, presuming that the bacteria wouldn’t resort to using its pili unless pressed. The tactic worked and the team was able to cause G. sulfurreducens to grow a mass of pili, which allowed them to study how they interacted with uranium. They found that the pili served as a buffer of sorts, protecting the cell structure of the bacterium as they also allowed for adding electrons to uranium ions which causes it to become more water soluble and thus safer to handle and clean up.The pili grow to enormous lengths (though they are very then – only a few nanometers) relative to the bacteria that produce them, forming a conductive and protective barrier that allows the bacteria to thrive in truly hostile environments.The study, part of ongoing research into so-named bioremediation; using organisms to remove unwanted substances from soil and water, adds to the growing body of knowledge that scientists hope will one day soon provide a means for dealing with a wide variety of environmental pollutants.As for Reguera and her team, they hope their research eventually leads to getting away from using biological bugs to clean up toxic environments and more towards creating tiny little programmed robots that can mimic their actions but can be more easily manipulated into doing exactly what is needed in particular circumstances. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Astronomer urges researchers everywhere to study Venus transit

first_img Venus to appear in once-in-a-lifetime event Citation: Astronomer urges researchers everywhere to study Venus transit (2012, May 17) retrieved 18 August 2019 from https://phys.org/news/2012-05-astronomer-urges-venus-transit.html (Phys.org) — Jay Pasachoff, Director of Hopkins Observatory, Chair of the Astronomy Department at Williams College and Field Memorial Professor of Astronomy, has written a commentary piece published in the journal Nature, urging stargazers everywhere to take advantage of the unique opportunity to study the Venus transit, which will occur June 5-6. It will be, he reminds readers, a once in a lifetime opportunity. Explore further Journal information: Nature More information: Transit of Venus: Last chance to see, Nature 485, 303–304 (17 May 2012) doi:10.1038/485303acenter_img Because of their orbits, Venus only rarely crosses the sun from an Earthly perspective. It does so in a predictable pattern though which repeats every 243 years. Each time the transits come in pairs however, separated by eight years with gaps of 121.5 years and 105.5 years. The last event was 1874-1882, while this one is 2004 and 2012, i.e. this year. The Venus transit occurs when Venus comes between the Earth and the sun, and is actually the same thing as a lunar eclipse, the only differences being the relative sizes of the objects and their distances from the Earth and sun.Pasachoff writes that researchers from all over the world should take advantage of the opportunity to study an event that will not occur again in our lifetime, suggesting it’s a moral obligation astrophysicists and astronomers should take seriously. One of the major benefits of studying the transit, he suggests is the opportunity to compare measurements based on one kind of event with those of another to help with calibrating both instruments and mathematical modeling. Doing so, he adds, could help researchers in the future better identify exoplanets, which of course, could lead to the discovery of life existing in places besides our home planet. One example would be carefully measuring Venus’s diameter as it crosses the sun and then comparing that with measurements taken using other methods.Making matters even more urgent is the fact that during this transit, our sun will be displaying sun spots, which Pasachoff says, allows for comparing changing light patterns of suspected exoplanets with those that occur much closer to home. One way scientists are able to identify an exoplanet is by measuring the dimming of a star as a planet passes between it and us, though sometimes other events can cause dimming as well. One of those is thought to be star flares, (akin to solar flares). By measuring the differences in amounts of light that reaches us during the Venus transit and then comparing that with the amount that reached us during the 2004 transit, which occurred during a time with no sunspots, researchers can more accurately predict whether star dimming is the result of distant transits or flaring.Pasachoff adds that regardless of area of interest, the more people studying the transit the better, in as many ways as possible, even if there doesn’t seem to be any immediate payoff. Information gathered during the transit, he points out, could very well reveal pertinent information later on. The 2004 transit of Venus. Photo taken by Jan Herold. © 2012 Phys.Org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Ford explores call turnoffs for stressedout drivers

first_img(Phys.org) — No calls for you. That is the word from a new technology experiment by Ford, for stressed-out drivers who risk accidents by distractions from incoming calls, playing music, and other vehicle infotainment sources. Having to maneuver the vehicle in heavy traffic places demands on focused safe driving. Risks are compounded by distractions when coping with tricky ramp-merging scenarios or blind-spot monitoring or coping with other vehicles that are frequently changing lanes, for example. Ford this week performed a demo of its “Driver Workload Estimator” that will limit phone and text distractions when deciding that the driver’s stress levels call for safety intervention. Citation: Ford explores call turnoffs for stressed-out drivers (2012, June 28) retrieved 18 August 2019 from https://phys.org/news/2012-06-ford-explores-turnoffs-stressed-out-drivers.html Overall, the detectors would be using real-time data from throttle, brakes steering wheel, and seatbelt, and meshing it with information from sensors and cameras. Ford is fundamentally working on an algorithm to create the estimator. So what good is all this monitoring, for what end? Based on the information received, the system then is designed to take steps to intervene and reduce distractions when the driver is under heavy stress. Ford says that “the car could intelligently apply the Do Not Disturb feature that is already available as part of MyFord Touch, helping the driver stay focused on the road during the high-demand situation.” Ford’s algorithm asks the question if the driver is stressed or driving into a high-stress situation. If the answer is yes, Ford says the car would trim back auxiliary systems and beef up other ones so that the driver would remain as focused as possible. The data would determine external demands placed on the driver at any time due to traffic and road conditions. Sensors would gauge physical states, such as a rise in heart rate. The car would then “intelligently” filter out incoming calls. In lighter traffic and under safer conditions, the driver would then be allowed to field calls or get texts. The technology is still in research. “With today’s ever-increasing concern about driver distraction, engineers in the Ford Research and Innovation labs are developing ways to help the driver stay focused in busy situations by intelligently managing incoming communications,” said the company. Explore further Ford’s Cloud-Connected car, the Evos Concept, to make North American debut at 2012 CEScenter_img More information: media.ford.com/article_display … cfm?article_id=36728 Outstanding features in its new foray into workload-estimating is in the range of sensors taking information from the driver’s body. There is a palm temperature sensor, heart rate monitor, and a sensor in the seatbelt to check a driver’s breathing rate. In the company’s press statement, Gary Strumolo, manager of vehicle design and infotronics, Ford Research and Innovation, said.”Biometric or health information of the driver can help us better tailor the experience when behind the wheel.” © 2012 Phys.Org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Improvedyield dandelions prepped for tire production

first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Efforts to develop alternative sources of natural rubber are due to marketplace conditions where demand exceeds supply. According to estimates, demand worldwide for rubber will outstrip supply by 20 per cent in 2020. The problem is that, according to tire manufacturers, Apollo Vredestein, it is not possible to simply replace natural rubber extracted from the rubber tree with a synthetic variant.To reduce dependence on the rubber tree, alternatives are sought. At KeyGene’s special greenhouse environment, experiments are carried out in developing the dandelion to the point where it can become a rubber-source crop. This takes work. Because the dandelion’s roots are smaller than ideal for commercial rubber production, KeyGene scientists have subjected the plant to its phenotyping process. The team hopes to achieve a more useful variety with a fatter root and higher yield, to better meet the demands of industrial processing. According to reports, Apollo Vredestein has joined KeyGene in a collaborative dandelion development effort. A prototype tire has already been produced. “Although first impressions look very promising,” according to a company statement, “the tires with the alternative natural rubbers will first undergo extensive testing over the coming months before being taken into production.”KeyGene, which describes itself as a molecular genetics R&D company, uses an approach that analyzes specimens of a given crop, scanning for mutations that will be beneficial in terms of yield or sustainability. The genetic material of strains with desirable characteristics is isolated and sequenced to create improved crops. As for the dandelion, in aiming for crop potential, the tinkering has involved “making crosses between” the Russian dandelion with the common dandelion, using DNA profiling technologies. KeyGene emphasizes that its method represents a quicker and more economical way of crop improvement than genetic modification. The company’s CEO, Arjen Van Tunen, said, “We don’t introduce a gene from a different species into our crops.” He pointed out that the company works “without crossing the species barriers.” The team works with the DNA in the species itself.Beyond KeyGene, the dandelion continues to be of interest for industrial use. The EU-PEARLS in Europe is a joint project between European research organizations and industrial partners. Its interest similarly is in the Russian dandelion as well as the desert plant, guayule. Another sign of dandelion interest was noted last year, when Bridgestone Americas said it would continue to test the dandelion at its lab facilities and would engage in larger-scale testing in 2014. Citation: Improved-yield dandelions prepped for tire production (2013, February 19) retrieved 18 August 2019 from https://phys.org/news/2013-02-improved-yield-dandelions-prepped-production.html Explore further Latex hunt produces key results in Europecenter_img More information: www.eu-pearls.eu/UK/ (Phys.org)—With supply falling short of demand for natural rubber, scientists in The Netherlands are literally planting seeds of hope for a viable solution. Researchers at the Dutch biotech firm KeyGene are engaged in developing the dandelion into a promising source of rubber. The dandelion’s roots contain latex, the milky liquid that is a source for natural rubber. The latex from dandelion roots could serve as a needed source of material for tires. © 2013 Phys.orglast_img read more

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Astronauts skin changes before and after missions are studied

first_img The team of researchers went looking for answers, said David Moceri on Tuesday in Capital Wired. Over the years, he said, it was observed that many astronauts suffered skin problems. What happens to human skin during a journey to space?Both the European Space Agency and NASA asked a team from the Department of Biophotonics and Laser Technology at Saarland University for more information.Three astronauts were examined before and after their space journey. Reactions of skin structure to a mission were imaged using advanced imaging technology. Moceri said, “According to them, this imaging technology is similar to a real tissue biopsy, providing detailed information that helps the researchers learn more about the skin layers after spending time in space.”Findings: The morphology of the skin suffers changes during space travel. First off, skin produced a higher level of collagen in space. Second, the epidermis was shrinking, especially in the region of living cells. “The scientists said that the epidermis got thinner by almost 20 percent than it usually is,” said Moceri.Discussing the technology at play in this investigation, Professor Karsten Koenig from the Department of Biophotonics and Laser Technology at Saarland University said in a Monday Reuters report that “We use femtosecond laser pulses. We scan the skin and we get signals from the skin, particularly fluorescence, as well as another signal called second harmonic generation. So with these two signals we can build up images and get a precise look into the skin with a high resolution.” Koening said the resolution was a factor of one thousand (times) better than ultrasound.The technique means researchers can get the information in seconds that would otherwise need to come from taking biopsies, slicing them, staining them, and having a pathologist study them, Nonetheless, there is more research to be done. Scientists have been made aware what happens but they still search for more information. “So far we have no explanation yet, and we are waiting for the other astronauts to figure out what’s going on and maybe to try to figure out how we can protect, how we can help so that this epidermis is not shrinking,” said Koenig in the Reuters report.Koenig and his team will continue looking into what causes the thinning of astronauts’ skin – and more crucially, how it can be prevented, said Reuters. “We’ve seen the epidermis get thinner by nearly 20 percent. And so far we have no explanation.” © 2015 Phys.org. All rights reserved. Explore further As NASA once put, space is no trip to the spa. Changes in skin occur during spaceflight. According to recent reports, scientists have found that skin of astronauts who spend a lot of time in space gets thinner. This May 2010 NASA handout image shows a NASA astronaut participating in the mission’s first session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. The two final US space shuttle missions before the shuttle program is phased out will likely be postponed, a NASA spokesperson told AFP on Friday.center_img Citation: Astronauts’ skin changes before and after missions are studied (2015, July 21) retrieved 18 August 2019 from https://phys.org/news/2015-07-astronauts-skin-missions.html 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. Diode laser safe, effective for treating facial skin laxitylast_img read more

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Paschim Vihar is buzzing

When star properties started opening up in far-flung areas like Rohini, Janakpuri etc, the first question that cropped into my mind is that why would that make business sense. Friends in the business told me of the tremendous business restaurants of these hotels have been doing — sometimes, I am told — much more than south Delhi five stars. I still shook my head in disbelief. But the feeling lasted till the time I visited a star-property in Janakpuri and saw people from that part of the town coming over in hordes for a lazy meal. Since then, whenever I have gone to these ‘far-flung places’ [and any south Delhiite will call them that], I have always found the restaurants choc-a-bloc, doing brisk business. Also Read – ‘Playing Jojo was emotionally exhausting’Which is why I travelled to Paschim Vihar to check out Level 2, the multicuisine all-day diner at Radisson Blu Hotel New Delhi Paschim Vihar! At about 9.30 pm, people were waiting outside, since the restaurant was already packed. Which spelt good news to me. Level 2 is spread over quite a large area, with comfortable seating. The all-glass bar room is certain to catch your eye and displays a wide selection of alcohol. The fastest moving items here are mostly Indian, apart from popular dishes like pasta and pizza. The menu card is chunky so that people are spoilt for choice. They also have a section for the health conscious. Also Read – Leslie doing new comedy special with NetflixI tried a mix of Continental and Indian. However, I preferred the Continental dishes over the Indian ones. The kebabs were just about okay but the dim sums were good. If you are a light eater, I would recommend the Steamed sea bass in lemon sauce. Check it out.  DETAILAt: Radisson Blu Hotel New Delhi Paschim Vihar, Plot D, District Centre, Outer Ring Road, Paschim Vihar Timings: All day Phone: 4639 9999 Cost: Rs 1,500 + taxes [for dinner] read more

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Not enough money organisers

first_imgThe sixth edition of the Jaipur Literature Festival is running on a negative budget of over Rs 1.5 crore with several sponsors pulling out in the last three weeks citing financial constraints, said organisers.‘Our budget for this year is between Rs 5 crore-Rs 6.8 crore but we managed to garner only Rs 4 crore in sponsorships,’ festival producer Sanjoy K Roy said.He said they had covered the budget for this year through sponsorships. ‘But in the last three weeks, many pulled out. And by that time, it was too late find new sponsors.’ Also Read – ‘Playing Jojo was emotionally exhausting’‘Looks like we will lose money,’ he said, adding that they had last year managed to recover the cost of the event, billed as the largest literary festival in the Asia-Pacific region. He said his entertainment company Teamwork Production would have to foot the unrecovered bill.Festival co-director and writer Namita Gokhale had also said in her opening speech that they were ‘Rs 1.5 crore behind budget. It is a bad financial year,’ she said.Asked if the negative balance will affect the festival plans next year, Roy said: ‘We have to find new ways to get money.’ Also Read – Leslie doing new comedy special with NetflixHe said it was hard to downsize the festival. ‘People come with big expectations. The festival has become one of five largest in the world. We have no choice.’According to estimates till Thursday, he said, the footfall at the event was likely to cross 97,000. The five-day festival ends on Monday. The 2012 edition had seen 120,000 footfalls.Over 280 authors from across the world are attending the festival this year. Entry to all the venues is free. Asked if sponsors seek presence of celebrities at the festival for more crowds, Roy said: ‘It’s not about celebrities anymore.’ People came anyway because of the event’s popularity, he said.On adding naming of the sponsors to session venues, he said: ‘They want returns! Since they cannot get tangible returns, like real sales, but only brand returns, so we try to invent new branding opportunities.’He said one sponsor wanted to have a session on arts or an English newspaper wanted a session on international relations or another on language writers. ‘We have to understand the needs of the sponsors. They are not doing charity. They have to get something out of it and we have to meet their requirements.’The two consistent sponsors of the event continue to be infrastructure company DSC Ltd and Diggi Palace, the heritage resort in this Rajasthan capital that has been hosting the literary carnival. The other big sponsors are Tata Steel, Google, Airtel and Coco-Cola. (IANS)last_img read more

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Zohra Redux

first_imgThe Indira Gandhi National Centre for the Arts (IGNCA) Film Circle will be screening the film Zohra Unmasked directed by Jai Chandiram, this friday (8 August). IGNCA screens two films a month, one on the second and the other on the fourth Friday. The film walks through the life of Seghal, the acclaimed Indian actress whose career in Bollywood spanned over 60 years. Belonging to an aristocratic family of Nawabs, it was unusual for Sehgal to show her urge to become a dancer. She went to Germany, and got a three year diploma in dancing. Also Read – ‘Playing Jojo was emotionally exhausting’It was a training in expressing the consciousness of one’s body, using appropriate postures and adding emotions to the performances. In the documentary, she shares her training experiences in expressing the consciousness of one’s body.On her return, she joined the dancing school of Uday Shanker. In Mumbai, she joined the theatre group of Prithvi Raj Kapoor and worked with him for fifteen years, and even acted in films with him. Her husband’s death made her shift to London. But, she wanted to return to her roots and came back to Mumbai. The personality of this great danseuse, actress and the theatre personality is unveiled by Kapila Vatsyayan.When: 8 August (Friday)Where: Media Centre Auditorium, IGNCA, 3 Dr. Rajendra Prasad RoadTiming: 6 pmlast_img read more

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