Citation: Bouncing atoms may be the key to the future of gravimetry (2009, April 27) retrieved 18 August 2019 from https://phys.org/news/2009-04-atoms-key-future-gravimetry.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. (PhysOrg.com) — When studying cold atoms, scientists often use magnetic or optical traps to keep the atoms in place. However, in some cases experimentalists want to study free atoms, avoiding the effects of a trap. “One way to study free atoms,” Cass Sackett tells PhysOrg.com, “is by bouncing them off a surface… most of the time, the atoms are free.” He says that scientists have been interested in bouncing atoms for a long time, but that before now only about five bounces have been achieved. “Using magnets and certain lasers, it is possible to bounce atoms. However, they are lost relatively quickly.” A step closer to a practical atom laser Explore further Sackett, a scientist at the University of Virginia in Charlottesville, and his colleagues, Hughes and Burke, have managed to construct a scheme in which they were able to get 100 bounces out of atoms. “We succeeded with finely tuned laser pulses,” Sackett explains. The Virginia team’s work can be seen in Physical Review Letters: “Suspension of Atoms Using Optical Pulses, and Application to Gravimetry.”“There are a number of experiments done with falling atoms,” Sacket says. “We focus on the use of our bouncing scheme for measuring gravity, though.” Gravity can be measured very accurately using falling atoms, but it requires large equipment. “If you want to probe these atoms for precision measurements, you have let them fall a long way. The apparatus starts to get bigger and becomes awkward to handle. What are you going to do? You start talking about machines that are 10 meters tall so that you can drop atoms a longer way.”Instead of building large measuring devices, Sackett and his peers propose using a more compact system using bouncing atoms. “You get similar effects, with the number of bounces involved, so you don’t need something that allows the atoms to fall a long way,” he says. “We rely on the fact that we can control lasers so well to set up a situation that might be able to replace falling atoms in experiments.”While the team at the University of Virginia focused mainly on gravimetry applications, Sackett believes that this breakthrough could also be applied in other fields. “It might be used to improve atomic clocks and test for fundamental values of certain constants – constants like Planck’s constant.”Sackett also sees potential for experiments that so far need to be done in space. “Since you can suspend atoms in a way, it’s sort of similar to the conditions in space, where nothing falls. For instance, in gravity, you can only get atoms so cold before our cooling techniques stop working. I think with bouncing, we could get much colder, to well below one nano-Kelvin. And it would be a lot less expensive than sending an experiment into space on a rocket.”He is careful to underscore the fact that there is still a lot of work ahead to make the experiment work with the kind of precision they are hoping for. “Nothing new has to be developed,” Sackett says, “but we are working with different approaches to fine tune the process. There’s still quite a bit of work, but it looks promising, and we’ve taken the first steps.”More information: Hughes, Burke and Sackett, “Suspension of Atoms Using Optical Pulses, and Application to Gravimetry.” Physical Review Letters (2009). Available online: http://link.aps.org/doi/10.1103/PhysRevLett.102.150403 . Copyright 2009 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.
More information: The Scientist, “Can Mass Spec Really Do That?”: www.the-scientist.com/article/display/57115/ 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: Three Interesting Uses for Mass Spectrometry (2010, February 10) retrieved 18 August 2019 from https://phys.org/news/2010-02-mass-spectrometry.html Structure of hepatitis B virus mapped (PhysOrg.com) — When many think about mass spectrometry, they visualize uses in biomolecular work. This is because mass spectrometry used in MALDI and ESI techniques is much less harsh than ionization methods used before. These harsher methods often shatter the very proteins they are trying to measure. Mass spectrometry, though, doesn’t shatter the proteins, and provides useful insights into the life sciences. However, that’s not all mass spectrometry can be used for. © 2010 PhysOrg.com Explore further Here are three interesting (and somewhat surprising) uses for mass spectrometry:Measuring nanoparticle size: Usually, nanoparticles are measured with the use of transmission electron microscopy or x-ray diffraction. But what if you don’t have these fancy pieces of equipment? Interestingly, it appears that you can use a MALDI-TOF spectrometer to measure the size of nanoparticles. And, of course, once you have measured the size of a sphere, you can also calculate its density. The Scientist reports on research done by Anderson Marsh at Lebanon Valley College: Surprisingly, when he ran that calculation, Marsh found that nanoparticulate platinum is about 20% denser than its bulk counterpart. “I don’t know if that’s significant,” Marsh says, “but it could help explain some properties of metal nanoparticles, such as melting behavior and thermal expansion.” Looking for toxins in toothpaste: In some Chinese toothpastes, a toxic compound known as DEG is sometimes used as a sweetener. The compound is banned, but it is difficult to truly enforce the ban, since toothpaste is very difficult to test. It can be done, but it takes a lot of time. Until now. A Chinese scientist, Huanwen Chen, has come up with a way of using mass spectrometry to quickly screed for toxins. Additionally, this mass spectrometry method should also be transferable to testing other viscous liquids found in pharmaceuticals, biotechnology, other foods and chemicals. Looking for pesticides: Nutritional supplements are often touted as “natural” ways to boost health. However, the fact of the matter is that pesticides can find themselves in supplements and food. Unfortunately, testing for multiple pesticides is difficult. And is practically impossible without mass spectrometry. Douglas Hayward and Jon Wong at the U.S. FDA have developed a mass spectrometry method that can identify multiple compounds at once, hoping to reduce the amount of pesticides that enter the food supply.It will be interesting to see what applications are coming next.
Moon jellyfish, Gijon Aquarium. Courtesy of José Luis Acuña and Julio Arrontes, University of Ontario Explore further © 2011 PhysOrg.com Voracious comb jellyfish ‘invisible’ to prey Citation: Jellyfish replacing fish in over-exploited areas (2011, September 16) retrieved 18 August 2019 from https://phys.org/news/2011-09-jellyfish-fish-over-exploited-areas.html More information: Faking Giants: The Evolution of High Prey Clearance Rates in Jellyfishes, Science 16 September 2011: Vol. 333 no. 6049 pp. 1627-1629. DOI: 10.1126/science.1205134ABSTRACTJellyfishes have functionally replaced several overexploited commercial stocks of planktivorous fishes. This is paradoxical, because they use a primitive prey capture mechanism requiring direct contact with the prey, whereas fishes use more efficient visual detection. We have compiled published data to show that, in spite of their primitive life-style, jellyfishes exhibit similar instantaneous prey clearance and respiration rates as their fish competitors and similar potential for growth and reproduction. To achieve this production, they have evolved large, water-laden bodies that increase prey contact rates. Although larger bodies are less efficient for swimming, optimization analysis reveals that large collectors are advantageous if they move through the water sufficiently slowly. (PhysOrg.com) — Over-fished commercial stocks of plankton-eating fish have been replaced in several locations by jellyfish species. This appears to be something of a paradox because fish move quickly and can see their prey, which suggests their capture of prey should be much more efficient than for jellyfish that move slowly and have to make contact with their prey to know they are present. Now a team of scientists in Spain and the US have discovered he jellyfishes’ success is partly based on their large body size and its energy efficiency. The team studied previously published data on jellyfish species and found that their relatively large body size, long tentacles, and their habit of pulsing their bodies to draw plankton-laden water past their tentacles, all increase the chances of capturing nearby prey, and this body design enables them to compete successfully with the plankton-eating fish such as anchovies and sardines, even though a larger body size is less efficient for swimming.The study, published in the journal Science, compared mathematical models of factors such as energy efficiency, speed, and size for over 600 species of fish and jellyfish. The researchers, led by ecologist José Acuña of the Universidad de Ovied in Spain, found that their size and speed did not give fish as much of an advantage as previously assumed, when features such as the type of body, and a reliance on light were factored in.The jellyfish swimming style is slow but turns out to be highly efficient in terms of energy expended, and since most jellyfish species are blind, they can continue to feed regardless of the light conditions. These factors enable jellyfish to closely compete with the fish, and when fish numbers are in decline, they can become the dominant species.The type of body also had an effect on their success. The large, gelatinous jellyfish bodies are composed of around 96% water, and therefore contain disproportionately less carbon than fish bodies, which are made up of compact organic matter. When this was taken into account the researchers found jellyfish could clear the water of plankton to produce energy at a similar rate to the fish. Having a low-carbon body (and stinging cells on the tentacles of some species) also make jellyfish a less appetizing meal for predators than do their competitors.In some areas where fish stocks are declining, often through over-fishing or pollution, jellyfish are becoming the dominant species. These areas include coastal waters off Japan, Northeastern US, the Black Sea, and the Mediterranean. The increasing numbers could change the nature of marine ecosystems, and in some areas, such as Japanese coastal areas, it is already causing problems for human beach-goers. In Japan, Scotland, and Israel, nuclear power plants drawing water from the sea have also experienced problems and have had to shut down at times through an over-abundance of jellyfish clogging water intake filters. 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.
© 2011 PhysOrg.com Citation: Neural network learns to identify group sizes without knowledge of numbers (2012, January 23) retrieved 18 August 2019 from https://phys.org/news/2012-01-neural-network-group-sizes-knowledge.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: Emergence of a ‘visual number sense’ in hierarchical generative models, Nature Neuroscience (2012) doi:10.1038/nn.2996AbstractNumerosity estimation is phylogenetically ancient and foundational to human mathematical learning, but its computational bases remain controversial. Here we show that visual numerosity emerges as a statistical property of images in ‘deep networks’ that learn a hierarchical generative model of the sensory input. Emergent numerosity detectors had response profiles resembling those of monkey parietal neurons and supported numerosity estimation with the same behavioral signature shown by humans and animals. Journal information: Nature Neuroscience Explore further Math ability is inborn (PhysOrg.com) — A cognitive sciences research duo out of Università di Padova, in Italy, have succeeded in building an artificial intelligence network that has through repetition, learned to identify relative group sizes, without counting. Ivilin Stoianov and Marco Zorzi describe in their paper published in Nature Neuroscience, how they built an AI system capable of approximate number sense (ANS). ANS is the ability of living beings to estimate with reasonable accuracy the differences in sizes of different groups. Fish, for example, demonstrate an ability to join the larger of two schools without having to count. Getting a computer to do the same has until now, never been done.To get their AI network to develop ANS, the researchers used a neural network that “learns” to recognize images and to respond based on what it’s seen. The system used mimics the biological processes of the eyes and brain, where one layer artificially recreates the retina with neurons that fire when exposed to pixels in an image and another that attempts to recreate some of the functions associated with brain processing.After feeding the network 51,800 images, where each was a unique layout of rectangles of various sizes, the researchers found that the new images generated by the system began to demonstrate an awareness of the relative size of different groups without having to perform any counting. The new images the system created showed more artificial neurons firing when presented with images that showed groups with more elements in them.Next, to demonstrate, ANS, the team fed the system another program that allowed the system to compare different groups that it had seen during the first run and found, based on new images generated, that the system was able to make educated guesses about which was bigger or smaller; indicating the system had, without any numerical programming, learned to make educated guesses about which groups were bigger than others. This they say, is an example of ANS in an artificial network.In looking at how the system was able to learn to make educated guesses regarding relative group size, the team notes that the process appears to be very similar to that which occurs in the brains of living animals, including humans. Babies, for example have been found to be able to perform ANS, without any notion of counting.Teaching computer systems to learn to use ANS is but one step towards creating machines that think rather than simply crunch numbers for us, and the hope is that one day, such systems can be put into robots to make them as useful as those we’ve seen in movies for decades.
British government to fund 3D laser cameras for highway crash site investigations (Phys.org) — When car accidents happen, typically road closures soon follow. This is because police need to study the scene to try to determine what happened, who was at fault, etc. Part of that investigation involves measuring things such as length of skid marks, distance between vehicles, or even how much a car compressed during impact; all of which takes a considerable amount of time while still leaving room for errors. Now, a new way of recording accident scenes is being used by police in Essex England. It’s the RIEGL VZ-400 – part camera, part scanner that is able to faithfully record an accident scene in a 360° panorama. Citation: British police get 360 degree accident scene camera (2012, May 3) retrieved 18 August 2019 from https://phys.org/news/2012-05-british-police-degree-accident-scene.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. © 2012 Phys.Org The VZ-400 works by making use of both a 3D camera and a laser beam. The camera records imagery while the laser beam is used to fix objects in the images so that distances can be calculated. When put to use, the device slowly turns taking in and capturing 120,000 minute details every second of the scene around it. Afterwards, the information that is recorded is processed and a detailed 3D panorama is produced that allows officials to take a virtual tour of the crash scene whenever they wish, including during court proceedings.One of the highlights of the virtual tour is the ability to see distances between objects, displayed by the use of colored lines and numbers. Thus, police, insurance adjusters and other officials can use the calculated data to arrive at better estimates of how crashes likely occurred. Because the new device is so adept at capturing crash scene information, Essex police plan to use it for recording crime scenes as well, which can produce information that, authorities are quick to point out, can be used in trial proceedings.Test trials have shown that the VZ-400 typically produces a third more data than police officers on the scene at traffic accidents, and takes less than half the time to get the job done, meaning road closure times should be dramatically reduced. In tests done in London, road closures were shortened on average by an hour and a half.Even at the steep price of £108,000 ($175,000) apiece, twenty five police departments in Britain have announced that they too will be purchasing and using the new devices, though still unclear is just how many each department will be able to afford. Explore further
Explore further Scientists identify molecules in the ear that convert sound into brain signals Expression of TMC-1 in chemosensory neurons. Credit: (c) Nature (2013) doi:10.1038/nature11845 Citation: Study finds protein that helps nematodes avoid salt may also be involved in mammalian hearing (2013, January 31) retrieved 18 August 2019 from https://phys.org/news/2013-01-protein-nematodes-salt-involved-mammalian.html © 2013 Phys.org More information: tmc-1 encodes a sodium-sensitive channel required for salt chemosensation in C. elegans, Nature (2013) doi:10.1038/nature11845AbstractTransmembrane channel-like (TMC) genes encode a broadly conserved family of multipass integral membrane proteins in animals1, 2. Human TMC1 and TMC2 genes are linked to human deafness and required for hair-cell mechanotransduction; however, the molecular functions of these and other TMC proteins have not been determined3, 4, 5, 6. Here we show that the Caenorhabditis elegans tmc-1 gene encodes a sodium sensor that functions specifically in salt taste chemosensation. tmc-1 is expressed in the ASH polymodal avoidance neurons, where it is required for salt-evoked neuronal activity and behavioural avoidance of high concentrations of NaCl. However, tmc-1 has no effect on responses to other stimuli sensed by the ASH neurons including high osmolarity and chemical repellents, indicating a specific role in salt sensation. When expressed in mammalian cell culture, C. elegans TMC-1 generates a predominantly cationic conductance activated by high extracellular sodium but not by other cations or uncharged small molecules. Thus, TMC-1 is both necessary for salt sensation in vivo and sufficient to generate a sodium-sensitive channel in vitro, identifying it as a probable ionotropic sensory receptor. 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. In studying nematode reactions to high salt concentrations, the researchers manipulated the DNA of a specimen to remove the TMC-1, gene. Doing so they found, removed the nematode’s ability to sense high salt concentrations, a necessary ability to ensure its survival. Looking deeper, they discovered that the presence of the TMC-1 gene caused the nematode to produce a certain kind of protein that was involved in controlling an ion channel. Conversely, the absence of that protein meant the nematode was no longer able to avoid entering areas where high salt concentrations would spell its doom. This finding has led the researchers to wonder if the same protein might be involved with hearing in mammals.Prior research has shown that the TMC-1 gene is involved somehow in hearing in mammals, including humans. Problems with it generally mean problems with hearing. Up till now however, the mechanism involved has not been clear. This new research with the nematodes suggests that it might be possible that the same protein, or one very much like it, might be expressed in mammals, due to the TMC-1 gene – and that the protein might be responsible for controlling ion channels in the ears that serve as communication conduits between the tips of cilia in the ears and neurons that carry signals to the brain. If this is correct, it might mean researchers are on the right path to developing a way to treat people who have missing or impaired TMC-1 genes, and their related hearing problems.At this time, the connection between TMC-1 and ion channel control in mammals, is still speculative, but the team’s findings have alerted the health community to the possibility, which means that future research will likely be dedicated to investigating more closely the types of proteins found in the ears and the channels that carry sound information to the brain. Journal information: Nature (Medical Xpress)—A research team with members from Cambridge University in the U.K. and Korea University College of Medicine, has found that a protein expressed in nematodes may also be responsible for controlling an ion channel involved in hearing in mammals. In their study, described in the journal Nature, the team found that a protein expressed due to the TMC-1 gene, allows nematodes to avoid areas of high salt concentrations. Because TMC-1 genes have been linked with hearing problems in mammals, the researchers suggest that the same protein found in nematodes might be responsible for controlling ion channels in mammalian hearing.
© 2013 Phys.org Sony TVs show high-end color via quantum dot tech Explore further Comparison of LCDs without (left) and with (right) 3M’s QDEF solution. Credit: 3M Citation: Use of quantum dots with LCD screens in consumer devices edging closer to reality (2013, May 29) retrieved 18 August 2019 from https://phys.org/news/2013-05-quantum-dots-lcd-screens-consumer.html Quantum dots are very small bits of semiconducting nano-crystals—they’re useful because they can be confined in three spatial dimensions allowing for very tight control of emitted light at precise wavelengths. Shining a light through them produces exceptionally pure colors—applying trillions of them to a thin film allows for the display of color richness never before seen with LCD devices. Researchers have been raving about the benefits of the technology for several years while manufactures have been promising that devices with the technology would soon become available to consumers. It appears that such promises are finally about to come to fruition.In its press release, 3M says the company is near the end of a process that will lead to scaling-up of its Quantum Dot Enhancement Film (QDEF). They add that the newly developed film will allow for creating devices capable of displaying 50 percent more color than LCD devices (phones, tablets, TVs, etc.) currently on the market. Such devices, they claim will be brighter, lighter and will use less energy than conventional LCDs. Scaling up presumably means delivering their technology to manufacturers for producing the film in bulk—the timetable given is “sometime late second quarter” which should translate to next month if all goes according to plan. The film is to sit inside the existing backlit panel in display devices, meaning that no other new hardware will be required. This they say should allow for an easy transition with current devices. In a broader context, the announcement means that device makers could conceivably begin selling phones, tablets and television sets with QDEF technology as soon as this year’s holiday season.Sony’s Triluminos television sets, in contrast, are available right now. The company offer three models, all of which use quantum dots in their backlighting and all of which are price competitive, the company says, with traditional LCD based TVs. Sony has not revealed if the display technology inside the TVs will be made available for other types of devices. (Phys.org) —A recent press release by 3M announcing that its partnership with Nanosys, Inc. is about to bear fruit appears to be a sign that LCD’s with quantum dot technology are close to fulfilling the promise of much more colorful displays. Not to be outdone, Sony recently began shipping its quantum dot enabled Triluminos television sets to stores, garnering rave reviews in the process. 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)—In 2013, a group of physicists from Austria proposed the existence of a new and unusual force called the “blackbody force.” Blackbodies—objects that absorb all incoming light and therefore appear black at room temperature—have long been known to emit blackbody radiation, which repels small nearby objects such as atoms and molecules. But the physicists showed that blackbodies theoretically also exert an attractive force on these objects. They called this force the “blackbody force,” and showed that it can be stronger than blackbody radiation, and—for very small particles—even stronger than gravity. More information: C. R. Muniz et al. “Dependence of the black-body force on spacetime geometry and topology.” EPL. DOI: 10.1209/0295-5075/117/60001 Now in a new study published in EPL, a different team of physicists, C.R. Muniz et al., at Ceará State University and the Federal University of Ceará, Brazil, have theoretically demonstrated that the blackbody force depends not only on the geometry of the bodies themselves, but also on both the surrounding spacetime geometry and topology. In some cases, accounting for these latter factors significantly increases the strength of the blackbody force. The results have implications for a variety of astrophysics scenarios, such as planet and star formation, and possibly lab-based experiments.”This work puts the blackbody force discovered in 2013 in a wider context, which involves strong gravitational sources and exotic objects like cosmic strings as well as the more prosaic ones found in condensed matter,” Muniz told Phys.org.As the scientists showed in 2013, the blackbody force arises when the heat absorbed by a blackbody causes the blackbody to emit electromagnetic waves that shift the atomic energy levels of nearby atoms and molecules. These shifts cause the atoms and molecules to be attracted to the blackbodies due to their high radiation intensity, pulling them together.In the new study, the physicists investigated spherical blackbodies and cylindrical blackbodies, and showed how the topology and the local curvature of the spacetime influences their blackbody forces. They showed that ultradense spherical blackbodies like a neutron star (around which spacetime is highly curved) generate a stronger blackbody force due to the curvature compared to blackbodies in flat spacetime. They explain that this is because gravity modifies both the temperature of the blackbody and the solid angle at which the nearby atoms and molecules “see” the blackbody. On the other hand, a less dense blackbody such as our Sun (where spacetime is less curved) generates a blackbody force that is very similar to that of the flat case. The researchers then considered the case of a global monopole, a spherical object that modifies the global properties of space, and found a different kind of influence. Whereas for other spherical blackbodies, the spacetime influence is gravitational and decreases with the distance to the blackbody, for the global monopole the influence is of a topological nature, decreasing with the distance but eventually reaching a constant value.Finally, when investigating the blackbody force of cylindrical blackbodies around which spacetime is locally flat, the scientists found no gravitational correction to the temperature, but, surprisingly, an effect on the angles with nearby objects. And when a cylindrical blackbody becomes infinitely thin, turning into a hypothetical cosmic string, the blackbody force vanishes completely. Overall, the scientists expect that these newly discovered geometrical and topological influences on the blackbody force will help elucidate the role of this unusual force on objects throughout the universe.”We think that the intensification of the blackbody force due to the ultradense sources can influence in a detectable way the phenomena associated with them, such as the emission of very energetic particles, and the formation of accretion discs around black holes,” Muniz said. “That force can also help to detect the Hawking radiation emitted by these latter objects, since we know that such radiation obeys the blackbody spectrum. In the future, we would like to investigate the behavior of that force in other spacetimes, as well as the influence of extra dimensions on it.” Journal information: Europhysics Letters (EPL) Citation: New blackbody force depends on spacetime geometry and topology (2017, May 23) retrieved 18 August 2019 from https://phys.org/news/2017-05-blackbody-spacetime-geometry-topology.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. © 2017 Phys.org Blackbody radiation induces attractive force stronger than gravity Illustration of a cylindrical blackbody and a nearby atom. Credit: Muniz et al. ©2017 EPL
The fourth edition of Ibadat-E-Aman, a peace bridge of music initiative, was organised in the Capital at Stein Auditorium, India Habitat Cente on November 21 by Ehsaas Foundation and St. Stephen’s Society, Agra. It was staged in association with Indian Council of Cultural Relations.The famous duo of the Ustad Shafqat Ali Khan and Sandeep Silas ‘deep’, presented an evening of sufiyana kalaam along with Astha Dixit’s graceful Kathak performance. Shafqat belongs to the 500 year old Shaam Chaurasi Gharana of East Punjab, the poet Sandeep Silas ‘deep’ hails from Agra and Astha Dixit has learnt Kathak from Harish Gangani of Jaipur Gharana and Malti Shyam of Lucknow Gharana. Shafqat Ali Khan rendered sufi nazams and ghazals while Sandeep, recited sufiyana ghazals written by him. An innovation was presented on stage as Astha performed Kathak on Sandeep’s shayari sung in tarrannum. Ibadat-e-Aman stands for promoting the cause of peace in the Indian sub-continent at the level of artists committed to brotherhood and communal harmony.
Giving children rewards and allowing them a short nap after a period of learning can significantly boost their ability to remember new facts and skills for a long period, new research suggests.Memories associated with a reward are reinforced by sleep, the findings showed.“Rewards may act as a kind of tag, sealing information in the brain during learning,” said lead researcher Kinga Igloi from