Neanderthal faces were not adapted to cold

first_img © 2010 PhysOrg.com 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. Neanderthal faces had prominent cheekbones and wide noses previously thought to have developed in extremely cold periods because large sinuses were needed to warm air as it was inhaled. One problem with this theory is that modern people such as the Inuits, and other mammals living in Arctic regions have not developed large sinuses, and their sinuses are often smaller, and another problem is that it has never been proven that Neanderthal sinuses were larger. A team led by Dr Todd C. Rae from the Centre for Research in Evolutionary Anthropology at Roehampton University in the UK took previously published measurements of X-Rays and new data from three-dimensional (3D) computer tomography (CT) scans of nine Neanderthal skulls, all dated at over 28,000 years old. They then collected measurements from four Homo sapiens skulls from archaeological sites in Lithuania and dated from 300 to 1,500 years old. They compared the two sets of measurements to determine how large the sinuses of Neanderthals actually were. They used medieval Homo sapiens skulls rather than present-day skulls because they wanted data from a period before air conditioning and central heating, which could have affected the results.The results showed the Neanderthals did have larger sinuses than Homo sapiens, but the relationship between the size of the face and the size of the sinuses was the same in both species. This suggests the facial features were not related to adaptation to cold.Dr Rae said the results mean the idea of the faces being an adaptation to cold could now be dismissed, which he said “allows us to think about Neanderthals and their lives in new ways.” He said there had long been a view of Neanderthals as living on frozen tundra in the last glaciation, but it was more likely that they lived in temperate refuges, eating fruit and berries as well as meat. Dr Rae said attributing many of their physical traits to adaptations to extreme cold do not make any sense and a picture of them as a temperate creature fits the data better. He speculated that if Neanderthals were confined to warmer regions their populations could have been too isolated and small to survive the worst of the glacial times.Neanderthal fossils are found throughout Europe and parts of Asia. Recent research has found they used sophisticated tools, cooked their food, which included grains, vegetables and berries, and they may also have been able to speak.The paper is published in the Journal of Human Evolution. Citation: Neanderthal faces were not adapted to cold (2011, January 17) retrieved 18 August 2019 from https://phys.org/news/2011-01-neanderthal-cold.html More information: The Neanderthal face is not cold adapted, Journal of Human Evolution, Volume 60, Issue 2, February 2011, Pages 234-239. doi:10.1016/j.jhevol.2010.10.003 (PhysOrg.com) — New research into Neanderthal skulls suggests that facial features believed for over a century to be adaptations to extreme cold are unlikely to have evolved in response to glacial periods after all. First reconstruction of Neanderthal man. Image: Ther Neanderthaler Fund. Publisher: Marcus, Bonn. Via Wikipedia. Explore further Handsome by Chancelast_img read more

Robot influences behavioral development of quail chicks

first_img Citation: Robot influences behavioral development of quail chicks (2011, September 22) retrieved 18 August 2019 from https://phys.org/news/2011-09-robot-behavioral-quail-chicks.html ‘Mum! I’m hungry!’ Hungry chicks have unique calls to their parents The researchers, E. de Margerie, et al., from the University of Rennes 1 in Rennes, France, have published their study in a recent issue of Bioinspiration & Biomimetics.Although previous research has shown the importance of the mother hen in the development of quail chicks, using a mobile robot in place of the hen allowed the researchers to assess the impact with greater control. In their experiments, they divided 24 Japanese quail chicks into six groups of four. When the chicks were 36 hours old, the researchers began putting three of the groups in a cage with a heated mobile robot and the other three groups in a cage with the same heated robot, but with the locomotion feature disabled. Both of the cube-shaped robots had corridors between the wheels where the chicks could go to keep warm. All six groups of chicks met with their robot for one hour per day for 10 days. During this time, the autonomous mobile robot would occasionally move around the cage at random intervals, often followed by the chicks. In the control group, the robot remained stationary.After the 10 days of robot-quail meetings, the researchers began performing tests on the chicks. On the 13th day, the researchers placed the chicks back with their robots and observed that the chicks that spent time with the mobile robot moved around the cage much more actively and emitted more distress calls than the chicks that spent time with the stationary robot. However, the next day the researchers placed the chicks in the cage without robots, and although the chicks that met the mobile robot were still more active than the others, the difference was no longer significant.On the 14th day, the researchers made each chick face a grid between itself and three unfamiliar chicks. They found that the chicks that spent time with the mobile robot navigated around the grid more quickly than the other chicks (almost twice as quickly, on average). However, when the researchers repeated the test on the 20th day, the chicks that had spent time with the stationary robot improved their performance so that the difference was no longer significant.The results show that, five days after separation from the robots, the mobile robot improved the spatial learning and exploration skills of the chicks. Yet the impact was probably transitory, as the other chicks seemed to catch up with their peers after another five days. Although the effect was short-lived, the experiment is one of the first that shows how an autonomous robot can influence the behavioral development of animals. The researchers predict that more refined robots and prolonged meeting sessions may have stronger and more long-lasting effects on young animals. And, from the perspective of behavior development, the study shows that robots can underscore the results of past studies that show the importance of a mother hen’s mobility on the normal development of her chicks. More information: E. de Margerie, et al. “Influence of a mobile robot on the spatial behavior of quail chicks.” Bioinsp. Biomim. 6 (2011) 034001 (8pp). DOI:10.1088/1748-3182/6/3/034001 © 2011 PhysOrg.com Seven-day-old quail chicks stand near the heated robot. Image credit: E. de Margerie, et al. ©2011 IOP Publishing Ltd 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) — In one of the latest studies in the growing field of animal-robot interaction, researchers have found that young quail chicks that interact with autonomous mobile robots have improved spatial abilities later in life, at least up to a point. The results not only show the potential impact of robots on animal development, but also provide insight into the factors that play important roles in that development. Explore furtherlast_img read more

Japanese researchers turn a crab shell transparent

first_img New molecule may aid in production of biofuels and fungi-resistant plants Citation: Japanese researchers turn a crab shell transparent (2011, December 1) retrieved 18 August 2019 from https://phys.org/news/2011-12-japanese-crab-shell-transparent.html Journal information: Soft Matter Explore further A group of researchers working out of Kyoto University in Japan have successfully transformed a normal crab into one that is transparent. As they describe in their paper published in the British Royal Society of Chemistry journal, Soft Matter, the team used a chemical process to take advantage of the special properties of chitin, one of the main ingredients in crab shells. More information: Md. Iftekhar Shams, Masaya Nogi, Lars A. Berglund and Hiroyuki Yano, Soft Matter, 2012, Advance Article, DOI: 10.1039/C1SM06785KAbstractAn optically transparent crab-shell with an intact original shape and substantial morphological detail is presented. Inorganic calcium carbonate particles, proteins, lipids and pigments are removed from a native crab-shell, and the remaining chitin nanofibrous structure is impregnated by a monomer and polymerized. The nanostructural implications for man-made nanocomposites are discussed. An important application of the finding is demonstrated as heterogeneous micro-scale crab shell chitin particles are successfully used to process transparent nanocomposites. The incorporation of nanostructured chitin macro-particles not only retains transparency of the matrix resin but also drastically reduces the coefficient of thermal expansion of the polymer. Moreover, the optical transmittance of the composite is stable over a large range of temperatures despite significant inhomogeneity at the mm scale and the large temperature changes in the refractive index of the resin in its isolated state. This class of materials is an interesting candidate for transparent substrates in next-generation electronic devices such as flexible displays and solar cells. © 2011 PhysOrg.com The purpose of the research is to find new materials for making flexible displays for electronic devices or solar cells. After making the crab shell see-through, the team applied the same technique to a material made of crushed chitin and acrylic that was flattened to make a type of transparent paper.To make the crab transparent, it was first bathed in hydrochloric acid, sodium hydroxide and ethanol to remove everything from the shell that wasn’t chitin, leaving a plain white shell. They then soaked the shell in a bath of an acrylic resin monomer, which caused the chitin to become transparent. The resultant transparent crab retained all of the physical characteristics it had at the onset, which made for a rather odd-looking, eerie, specimen; somewhat reminiscent of a hardened jelly fish.Another positive aspect of chitin is the fact that it doesn’t expand when heated, a property that would be very useful when making flat or bendable type displays for televisions and computers or in solar cells that could be molded to fit real world surfaces. The paper-like material the team made turned out to be ten times as heat resistant as traditional materials such as glass-fiber epoxies, and it had a high light transmittance to boot.If chitin turns out to be the next great find in electronic materials science, it will be a lucky thing, as it’s quite plentiful in the natural world and not just in crab shells; it’s found in virtually all crustaceans, as well as many insects and most arachnids. It’s even found in the cell walls of many fungi. Technically defined as a horny polysaccharide, it’s a long chain polymer of a derivative of glucose and its primary use in the human world up to now has been as an ingredient in medicines and industrial products. 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 use quantum properties to create jammerproof radar

first_imgSchematic of our quantum-secured imaging experiment. Polarized single-photon pulses from a HeNe laser are reflected from the object and imaged onto an electron-multiplying camera (EMCCD) through an interference filter (IF). A half-wave plate (HWP) and a polarizing beamsplitter (PBS) are used to make the appropriate polarization basis measurement. Four images corresponding to the four measured polarizations are obtained. The angle of reflection is exaggerated in the figure for clarity but is less than 5 deg. in reality. The object consists of a reflective stealth aircraft silhouette. Credit: arXiv:1212.2605 [quant-ph] (Phys.org)—A trio of researchers from the University of Rochester in New York, has created a radar system based on polarized photons that they describe as jam-proof. The new system relies on the fact, the team writes in their paper uploaded to the preprint server arXiv, that any changes made to such a photon stream would be recognized as false by the system. More information: Quantum-secured imaging, arXiv:1212.2605 [quant-ph] arxiv.org/abs/1212.2605AbstractWe have built an imaging system that uses a photon’s position or time-of-flight information to image an object, while using the photon’s polarization for security. This ability allows us to obtain an image which is secure against an attack in which the object being imaged intercepts and resends the imaging photons with modified information. Popularly known as “jamming,” this type of attack is commonly directed at active imaging systems such as radar. In order to jam our imaging system, the object must disturb the delicate quantum state of the imaging photons, thus introducing statistical errors that reveal its activity. Citation: Researchers use quantum properties to create jammer-proof radar (2012, December 17) retrieved 18 August 2019 from https://phys.org/news/2012-12-quantum-properties-jammer-proof-radar.html Traditional radar systems work by shooting photons at a target and then measuring the reflections that occur as a result. Images of objects constructed using such a system can help discern the difference between a large bird and a small plane, for example. But, researchers have also developed ways to circumvent such systems, e.g. using flak, or generating false photon streams. This new system is an attempt to confound the latter.Quantum theory suggests that because of the unique nature of quantum particles, measuring them causes them to be changed. Thus, if a pilot in a war plane responds to radar signals by trying to send back a false pattern, he or she (their equipment actually) would have to know what the original photons looked like, which means they would have to be observed – a form of measurement. Doing so would cause them to be changed. Because of that, the photon stream that is sent back in reply would be obvious to the recipient because it would no longer match the properties of the stream that was sent.In their trial system, the researchers sent out a photon stream that had been polarized in one direction, then measured the photons as they were reflected back. They found an error rate of less than 1 percent. But when they set up a system to modify the photons before sending them back, the error rate jumped to close to 50 percent. This they say is more than enough to indicate that someone was attempting to jam their radar.The researchers acknowledge that more testing is needed, particularly in a real-world environment where it’s possible that natural elements might interfere with the polarization of photons, negating their results. Also, they note, there’s the problem of systems with multiple photon streams allowing for siphoning off of photons that go undetected by the system. On a more positive note, they also point out that technology currently exists to implement such a system in the real-world, and because of that, those that wish to, could build one right away if they chose to do so. Explore furthercenter_img © 2012 Phys.org Journal information: arXiv Hi-fi single photons 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

Simulations suggest global warming will increase strength of winds associated with AEWs

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. AEWs are tropical disturbances (bands of wind waves) that originate in the Atlantic Basin (the North and South Atlantic Oceans) and are thought to play a role in the development of tropical storms, including hurricanes (approximately 80 percent of tropical cyclones in the region have been linked to them). Climatologists studying current wind patterns are now attempting to understand what might occur as world temperatures rise due to greenhouse gas emissions. In this latest effort, researchers Christopher Skinner and Noah Diffenbaugh analyzed data from 17 global earth weather simulation models to discern if warming temperatures might have an impact on AWEs. Sadly, their research has revealed that the models (based on CO2 emissions doubling over the next century) suggest that warmer temperatures likely mean stronger winds associated AEWs. They note that that thus far, no evidence has been found that suggests stronger AEW winds would translate to more, stronger or bigger hurricanes, though many suspect that it’s likely to be the case. Stronger AEWs, they point out, means more energy in the system, and such energy is usually dispersed via tropical storms. They also point out that currently, less than fifteen percent of AEW disturbances result in the formation of major tropical storms.AEWs play another role in weather—prior research has shown that they are heavily involved in causing rain to fall in the Sahel and also tend to blow Saharan dust around on the African continent and into the atmosphere over the Atlantic Ocean. The models used by the researchers were not able to predict blowing dust patterns, but particulate matter in the atmosphere has previously been tied to the formation of tropical storms. Whether the impact of global warming on AEWs will mean more or less rain for Africa is still unclear. Journal information: Proceedings of the National Academy of Sciences Tropical waves formation. Credit: PD-USGov-NOAA © 2014 Phys.org More information: Projected changes in African easterly wave intensity and track in response to greenhouse forcing, Christopher Bryan Skinner, PNAS, 2014. DOI: 10.1073/pnas.1319597111AbstractSynoptic-scale African easterly waves (AEWs) impact weather throughout the greater Atlantic basin. Over the African continent, AEWs are instrumental in initiating and organizing precipitation in the drought-vulnerable Sahel region. AEWs also serve as the precursors to the most intense Atlantic hurricanes, and contribute to the global transport of Saharan dust. Given the relevance of AEWs for the climate of the greater Atlantic basin, we investigate the response of AEWs to increasing greenhouse gas concentrations. Using an ensemble of general circulation models, we find a robust increase in the strength of the winds associated with AEWs along the Intertropical Front in West Africa by the late 21st century of the representative concentration pathway 8.5. AEW energy increases directly due to an increase in baroclinicity associated with an enhanced meridional temperature gradient between the Sahara and Guinea Coast. Further, the pattern of low-level warming supports AEW development by enhancing monsoon flow, resulting in greater convergence and uplift along the Intertropical Front. These changes in energetics result in robust increases in the occurrence of conditions that currently produce AEWs. Given relationships observed in the current climate, such changes in the location of AEW tracks and the magnitude of AEW winds carry implications for the relationship between AEWs and precipitation in the Sahel, the mobilization of Saharan dust, and the likelihood of cyclogenesis in the Atlantic. Our results therefore suggest that changes in AEW characteristics could play a critical role in shaping the response of Atlantic basin climate to future increases in greenhouse gas concentrations.Press releasecenter_img Explore further Stronger, more frequent tropical cyclones ahead, research says Citation: Simulations suggest global warming will increase strength of winds associated with AEWs (2014, April 29) retrieved 18 August 2019 from https://phys.org/news/2014-04-simulations-global-strength-aews.html (Phys.org) —A pair of researchers at Stanford University is predicting an increase in the strength of winds associated with African Easterly Waves (AEWs) over the next century due to global warming—if levels of CO2 pumped into the atmosphere continue at the current rate. In their paper published in Proceedings of the National Academy of Sciences, the team describes their findings after studying 17 global earth weather models and what it might mean for future hurricane development.last_img read more

Surrey NanoSystems has super black material

first_imgCredit: Surrey NanoSystems e of carbon nanotubes – “each 10,000 times thinner than a human hair,” wrote Ian Johnston in The Independent on Sunday. It’s not what you see; it’s what you don’t see. If fact, you see nothing, period. “It is so dark that the human eye cannot understand what it is seeing,” wrote Johnston. “Shapes and contours are lost, leaving nothing but an apparent abyss.” The company explains why Vantablack is considered a breakthrough. “The manufacture of `super-black` carbon nanotube-based materials has traditionally required high temperatures, preventing their direct application to sensitive electronics or materials with relatively low melting points. This, along with poor adhesion, prevented their application to critical space and air-borne instrumentation. The two year development and test program was completed in December 2013, during which period Surrey NanoSystems successfully transferred its low-temperature manufacturing process from silicon to aluminum structures and pyroelectric sensors. As part of the program, qualification to European Cooperation on Space Standardization (ECSS) standards was also achieved.”Stephen Westland, professor of color science and technology at Leeds University, said in The Independent, “These new materials, they are pretty much as black as we can get, almost as close to a black hole as we could imagine.”Ryan Whitwam said in Geek.com, “There’s demand for something that reflects almost zero light when even a few photons can throw off an experiment.”What are some applications for this material? CNET mentioned its use in electro-optical imaging and target-acquisition systems. “One example of a use for the material is in telescopes to increase the instruments’ ability to see very faint stars.”Ben Jensen, the company CTO, detailed what the material could mean in applications. “Vantablack is a major breakthrough by UK industry in the application of nanotechnology to optical instrumentation. For example, it reduces stray-light, improving the ability of sensitive telescopes to see the faintest stars, and allows the use of smaller, lighter sources in space-borne black body calibration systems. Its ultra-low reflectance improves the sensitivity of terrestrial, space and air-borne instrumentation.”The company listed other special characteristics: It has virtually undetectable levels of outgassing and particle fallout, eliminating a key source of contamination in sensitive imaging systems. It withstands launch shock, staging and long-term vibration, and is suitable for coating internal components, such as apertures, baffles, cold shields and Micro Electro Mechanical Systems (MEMS) –type optical sensors. Citation: Surrey NanoSystems has “super black” material (2014, July 15) retrieved 18 August 2019 from https://phys.org/news/2014-07-surrey-nanosystems-super-black-material.html Explore further © 2014 Phys.org. All rights reserved. More information: www.surreynanosystems.com/news/19/ New ‘super-black’ material absorbs light across multiple wavelength bands (Phys.org) —A British company says it has scored a breakthrough in the world’s darkest material. Surrey NanoSystems describes its development as not just a black material but super-black. They are calling it Vantablack, and they are singling out its ability to be applied to lightweight, temperature-sensitive structures such as aluminum, absorbing 99.96% of incident radiation; that is, they said, believed to be the highest ever recorded. This coating is mad 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

Scientists turn to fireflies to improve OLED efficiency

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. The scientists, led by Ki-Hun Jeong at the Korea Advanced Institute of Science and Technology (KAIST), have published a paper on the firefly-inspired OLEDs in a recent issue of Nano Letters.”This work reports the first observation of hierarchical structures, i.e., inclined microstructures with nanostructures existing on the cuticular ultrastructures of a firefly’s lantern,” Jeong told Phys.org. “Based on our large-scale photonic calculation, it was clearly revealed that the function of asymmetric and hierarchical structures substantially contributes to the efficient extraction and wide angular illumination of bioluminescent light that would otherwise be entrapped in the firefly lantern. The knowledge learned from firefly lanterns has been successfully utilized for next-generation OLEDs.”The work builds on previous research (some by the same authors) that has shown that firefly cuticles have nanostructures that improve light transmission. The cuticles also have tiny structures that increase light extraction (the amount of light that actually exits the animal) by reducing internal reflection. The problem of internal reflection is one of the biggest challenges facing LEDs, where often more than half of the light produced is reflected back into the device rather than being emitted. Scientists have already mimicked these nano- and microstructures in LED design to improve light transmission and extraction.In the new study, the researchers have discovered that the asymmetric and hierarchical nature of the cuticle structures also plays a key role in the firefly’s light-emitting ability. The researchers created precise molds of these structures to use as the optical layer of an OLED. Consequently, the same features that help fireflies communicate their courtship signals have turned out to also contribute to improving advanced lighting and display applications. “Our breakthrough technology is the large-scale fabrication of inclined microstructures and highly ordered nanostructures on each inclined microstructure,” Jeong said. “We strongly believe that these biologically inspired OLEDs open a new paradigm for engineering biomimetics for lighting applications.”The firefly light may become a commercial reality in the near future.”We are looking for an industrial OLED partner who is interested in commercializing our novel idea, and we will also continue to work on biologically inspired photonics for engineering applications,” Jeong said. Citation: Scientists turn to fireflies to improve OLED efficiency (2016, April 20) retrieved 18 August 2019 from https://phys.org/news/2016-04-scientists-fireflies-oled-efficiency.html © 2016 Phys.org The biologically inspired OLED is patterned with hierarchical structures very similar to those on a firefly. Credit: Kim, et al. ©2016 American Chemical Societycenter_img More information: Jae-Jun Kim, et al. “Biologically Inspired Organic Light-Emitting Diodes.” Nano Letters. DOI: 10.1021/acs.nanolett.5b05183 Journal information: Nano Letters (Phys.org)—Many insects, birds, fish, and amphibians emit light as a way to communicate with each other, but the species that produces light most efficiently is the firefly. In a new study, researchers have investigated the optical properties of the firefly’s light-emitting cuticle, which is not smooth like most human-made lights, but instead is patterned with tiny hierarchical structures. Inspired by these features, the researchers replicated the patterns to create a bioinspired organic light-emitting diode (OLED), resulting in a 60% increase in the light extraction efficiency and 15% wider angle of illumination. Fireflies give Korean team bright idea for LED lightinglast_img read more

Gene transcription found to increase after death for some cells

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. © 2017 Phys.org Citation: Gene transcription found to increase after death for some cells (2017, January 25) retrieved 18 August 2019 from https://phys.org/news/2017-01-gene-transcription-death-cells.html Explore further (Phys.org)—An international team of researchers has found that gene transcription in an organism that has died continues for several days. In their paper published in the journal Royal Society Open Biology, the team describes their work analyzing gene expression in animals after their death. Journal information: Open Biologycenter_img Total mRNA abundance (arbitrary units, arb. units) by postmortem time determined using all calibrated microarray probes: (a) extracted from whole zebrafish, (b) extracted from the brain and liver tissues of whole mice. Each datum point represents the mRNA from two individuals in the zebrafish and a single individual in the mouse. Credit: Open Biology (2017). DOI: 10.1098/rsob.160267 New molecular mechanism revealed for genetic mutations in aggressive cancer cells More information: Alex E. Pozhitkov et al. Tracing the dynamics of gene transcripts after organismal death, Open Biology (2017). DOI: 10.1098/rsob.160267AbstractIn life, genetic and epigenetic networks precisely coordinate the expression of genes—but in death, it is not known if gene expression diminishes gradually or abruptly stops or if specific genes and pathways are involved. We studied this by identifying mRNA transcripts that apparently increase in relative abundance after death, assessing their functions, and comparing their abundance profiles through postmortem time in two species, mouse and zebrafish. We found mRNA transcript profiles of 1063 genes became significantly more abundant after death of healthy adult animals in a time series spanning up to 96 h postmortem. Ordination plots revealed non-random patterns in the profiles by time. While most of these transcript levels increased within 0.5 h postmortem, some increased only at 24 and 48 h postmortem. Functional characterization of the most abundant transcripts revealed the following categories: stress, immunity, inflammation, apoptosis, transport, development, epigenetic regulation and cancer. The data suggest a step-wise shutdown occurs in organismal death that is manifested by the apparent increase of certain transcripts with various abundance maxima and durations. Because death seems like such a conclusive event it is difficult for many to think about the possibility of life-like activities occurring in the bodies of those that have died. Most know that some cell activity continues, as evidenced by continued hair growth, but now it seems that many other cells continue living for longer than thought and some even exhibit behavior reminiscent of repair or regeneration.As the authors note, little research has been done regarding what happens with gene transcription when an animal dies—hence, they embarked on a study of the process in animals to find out. Their study consisted of identifying mRNA transcript activity in cells located in several body parts and then monitoring such activity for up to 96 hours. In so doing, they discovered that gene transcription diminished in some cells but continued in many others, and actually increased in some after death. They note that transcription increased at varied rates in different cells, but report they found some degree of commonality between animals, suggesting that it is not random.The researchers acknowledge that they did not find a reason for the continuation of gene transcription after death, but suggest it is likely due to the sudden stress placed upon the organism as a whole as they experienced the dying process. They note that cells involved in embryonic development, inflammation, immunity and cancers were most involved in increases of after-death gene transcription. They also suggest that their findings might shed light on why some donated organ recipients, particularly those receiving livers, tend to be more likely to develop cancer—gene transcription in liver cells that occurred after the original owner died could have resulted in tumor growth. They believe further study could lead to better understanding of what has occurred in donated organs before transplantation into needy patients and screen out those that might pose a cancer risk.last_img read more

Information engine operates with nearly perfect efficiency

first_imgPhysicists have experimentally demonstrated an information engine—a device that converts information into work—with an efficiency that exceeds the conventional second law of thermodynamics. Instead, the engine’s efficiency is bounded by a recently proposed generalized second law of thermodynamics, and it is the first information engine to approach this new bound. Artist’s illustration of the experiment. Credit: Burdette Choi, Institute of Basic Science Journal information: Physical Review Letters The results demonstrate both the feasibility of realizing a “lossless” information engine—so-called because virtually none of the available information is lost but is instead almost entirely converted into work—and also experimentally validates the sharpness of the bound set by the generalized second law.The physicists, Govind Paneru, Dong Yun Lee, Tsvi Tlusty, and Hyuk Kyu Pak at the Institute for Basic Science in Ulsan, South Korea (Tlusty and Pak are also with the Ulsan National Institute of Science and Technology), have published a paper on the lossless information engine in a recent issue of Physical Review Letters.”Thinking about engines has driven the progress of thermodynamics and statistical mechanics ever since Carnot set a limit on the efficiency of heat engines in 1824,” Pak told Phys.org. “Adding information processing in the form of ‘demons’ set new limitations, and it was essential to verify the new limits in experiment.” Traditionally, the maximum efficiency with which an engine can convert energy into work is bounded by the second law of thermodynamics. In the past decade, however, experiments have shown that an engine’s efficiency can surpass the second law if the engine can gain information from its surroundings, since it can then convert that information into work. These information engines (or “Maxwell’s demons,” named after the first conception of such a device) are made possible due to a fundamental connection between information and thermodynamics that scientists are still trying to fully understand. Naturally, the recent experimental demonstrations of information engines have raised the question of whether there is an upper bound on the efficiency with which an information engine can convert information into work. To address this question, researchers have recently derived a generalized second law of thermodynamics, which accounts for both energy and information being converted into work. However, no experimental information engine has approached the predicted bounds, until now. The generalized second law of thermodynamics states that the work extracted from an information engine is limited by the sum of two components: the first is the free energy difference between the final and initial states (this is the sole limit placed on conventional engines by the conventional second law), and the other is the amount of available information (this part sets an upper bound on the extra work that can be extracted from information). To achieve the maximum efficiency set by the generalized second law, the researchers in the new study designed and implemented an information engine made of a particle trapped by light at room temperature. Random thermal fluctuations cause the tiny particle to move slightly due to Brownian motion, and a photodiode tracks the particle’s changing position with a spatial accuracy of 1 nanometer. If the particle moves more than a certain distance away from its starting point in a certain direction, the light trap quickly shifts in the direction of the particle. This process repeats, so that over time the engine transports the particle in a desired direction simply by extracting work from the information it obtains from the system’s random thermal fluctuations (the free energy component here is zero, so it does not contribute to the work extracted).One of the most important features of this system is its nearly instantaneous feedback response: the trap shifts in just a fraction of a millisecond, giving the particle no time to move further and dissipate energy. As a result, almost none of the energy gained by the shift is lost to heat, but rather nearly all of it is converted into work. By avoiding practically any information loss, the information-to-energy conversion of this process reaches approximately 98.5% of the bound set by the generalized second law. The results lend support for this bound, and illustrate the possibility of extracting the maximum amount of work possible from information.Besides their fundamental implications, the results may also lead to practical applications, which the researchers plan to investigate in the future.”Both nanotechnology and living systems operate at scales where the interplay between thermal noise and information processing is significant,” Pak said. “One may think about engineered systems where information is used to control molecular processes and drive them in the right direction. One possibility is to create hybrids of biological systems and engineered ones, even in the living cell.” Quantum manipulation power for quantum information processing gets a boost Explore further © 2018 Phys.org More information: Govind Paneru, Dong Yun Lee, Tsvi Tlusty, and Hyuk Kyu Pak. “Lossless Brownian Information Engine.” Physical Review Letters. DOI: 10.1103/PhysRevLett.120.020601 Citation: Information engine operates with nearly perfect efficiency (2018, January 19) retrieved 18 August 2019 from https://phys.org/news/2018-01-efficiency.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.last_img read more

Wearing it wrong

first_imgSometimes men don’t pay much attention to their personal styling or the way they dress up. When it comes to fashion, most men simply try to avoid looking ridiculous. Sheena Agarwaal from Urbanista Image Consulting picks out a few faux pas that are being made all too often:White socks with dress shoesTeaming white socks with dress shoes may have enjoyed brief popularity in the mid-’90s, but there’s a good reason this combo has failed to make a strong comeback. Dress shoes should only be worn with dress socks, which are wool or cotton socks in dark hues.  Also Read – ‘Playing Jojo was emotionally exhausting’Buttoning blazers incorrectlyFastening the wrong number of buttons on your blazer can cause it to pull and stretch in awkward directions. Double-breasted jackets should nearly always be buttoned. With a two-button suit, fasten the top button and with a three-button suit, you have a choice between fastening the top two buttons or the middle one only. No matter what kind of blazer you’re wearing, always unbutton it when you sit down.Stuffed pocketsYour pants pockets are a place to put your hands, some spare change and perhaps a slim wallet. Bulging pockets detract from an otherwise streamlined look, so if you notice any square lumps in your pants, it’s a sure sign that it’s time to get a bag. Mismatched suit and shoes Also Read – Leslie doing new comedy special with NetflixMen too frequently select shoes in shades that don’t complement their dress clothes, like brown-hued footwear with black trousers. Pair black suits with black shoes; gray suits with black or camel shoes; brown suits with brown or camel shoes; and navy suits with black, camel, tan or oxblood-colored footwear.Wearing running shoes outside the gymActivewear should not be day wear. For a just-as-comfortable alternative without the ‘ick’ factor, pick a pair of sneakers or slip-on loafers for  your casual ensembles.last_img read more