Scientists study why the blind salamander lives so long

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. Scientists develop resource to study animal aging More information: Extreme lifespan of the human fish (Proteus anguinus): a challenge for ageing mechanisms, Biology Letters, Published online before print July 21, 2010, doi:10.1098/rsbl.2010.0539 The blind salamander (Proteus anguinus), also known as the olm, has the longest lifespan of any amphibian, often living to over 70 in zoos, and with a predicted maximum age of over 100. It reaches sexual maturity during its fifteenth year and lays about 35 eggs every 12.5 years.The amphibian spends its entire life in water in the dark limestone caves in southern Europe. Its eyes are atrophied and it has almost no skin pigments. The skin looks pink because the blood shows through, leading to the olm sometimes being called the “human fish”.The olm is a snake-like creature 25-30 cm long and weighing only up to 20 grams. Most tiny creatures have short lifespans, which is thought to be due to having higher metabolisms that in essence burn the creatures out more quickly, but the olm has a similar metabolic rate to its closest relatives, which have much shorter lifespans. There is also no unusual antioxidant activity in the olm that might explain its longevity.Scientists at a cave station set up at Moulis, Saint-Girons in France have been studying the olm, an endangered species, since 1952. The cave is a faithful reproduction of the olm’s natural habitat and has over 400 salamanders in residence. It is the only successful breeding program of the amphibian, and the project is operated by the National Center for Scientific Research in France. Data on deaths and breeding activity have been recorded at the cave station since 1958.Ecophysiologist Yann Voituron and colleagues, from the Université Claude Bernard Lyon, have been studying the salamanders to try to understand why they live so long in comparison to their relatives. Voituron said they would like to look at the “usual genes associated with increases in lifespan, and maybe hope to detect something new.” They would also like to analyze the creatures on a cellular level and examine their mitochondria, for example, but this would necessitate killing the animals, and they do not want to do this because they have so few to work with.The scientists estimated the maximum age from the knowledge the oldest inhabitants of the cave are now at least 48 and probably in their mid or late fifties, and in related species the average lifespan is between 10 and 67 percent of the longest lifespan known for the species. This gives a conservative estimate of a maximum lifespan of 102 years for the olm, or almost double the maximum lifespan of other long-lived amphibians such as the Japanese giant salamander, with a maximum of 55 years.Voituron said the studies have shown the olm is extremely inactive and rarely moves except to feed and to reproduce (which only happens every 12.5 years). There are no predators in the caves, so they live a stress-free life. The researchers think the salamander’s limited activity and an adjusted physiology may be a way to reduce production of reactive oxygen species (that damage cells as they age) without increased antioxidants or a lower basal metabolic rate. The paper, published online in the journal Royal Society Biology Letters concludes the olm raises questions about agiing and “appears as a promising model” to study mechanisms preventing aging processes in vertebrates. Citation: Scientists study why the blind salamander lives so long (2010, July 22) retrieved 18 August 2019 from https://phys.org/news/2010-07-scientists-salamander.html Explore further (PhysOrg.com) — Scientists have long been intrigued by the longevity of a tiny amphibian known as the blind salamander, but it now seems it may live a long time because it basically has no life. Proteus anguinus. Image crecit: CNRSlast_img read more

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Scientists suggest spacetime has no time dimension

first_imgScientists propose that clocks measure the numerical order of material change in space, where space is a fundamental entity; time itself is not a fundamental physical entity. Image credit: Wikimedia Commons. (PhysOrg.com) — The concept of time as a way to measure the duration of events is not only deeply intuitive, it also plays an important role in our mathematical descriptions of physical systems. For instance, we define an object’s speed as its displacement per a given time. But some researchers theorize that this Newtonian idea of time as an absolute quantity that flows on its own, along with the idea that time is the fourth dimension of spacetime, are incorrect. They propose to replace these concepts of time with a view that corresponds more accurately to the physical world: time as a measure of the numerical order of change. © 2010 PhysOrg.com In the future, the scientists plan to investigate the possibility that quantum space has three dimensions of space, as Sorli explained.“The idea of time being the fourth dimension of space did not bring much progress in physics and is in contradiction with the formalism of special relativity,” he said. “We are now developing a formalism of 3D quantum space based on Planck work. It seems that the universe is 3D from the macro to the micro level to the Planck volume, which per formalism is 3D. In this 3D space there is no ‘length contraction,’ there is no ‘time dilation.’ What really exists is that the velocity of material change is ‘relative’ in the Einstein sense.”Numerical order in spaceThe researchers give an example of this concept of time by imagining a photon that is moving between two points in space. The distance between these two points is composed of Planck distances, each of which is the smallest distance that the photon can move. (The fundamental unit of this motion is Planck time.) When the photon moves a Planck distance, it is moving exclusively in space and not in absolute time, the researchers explain. The photon can be thought of as moving from point 1 to point 2, and its position at point 1 is “before” its position at point 2 in the sense that the number 1 comes before the number 2 in the numerical order. Numerical order is not equivalent to temporal order, i.e., the number 1 does not exist before the number 2 in time, only numerically. As the researchers explain, without using time as the fourth dimension of spacetime, the physical world can be described more accurately. As physicist Enrico Prati noted in a recent study, Hamiltonian dynamics (equations in classical mechanics) is robustly well-defined without the concept of absolute time. Other scientists have pointed out that the mathematical model of spacetime does not correspond to physical reality, and propose that a timeless “state space” provides a more accurate framework.The scientists also investigated the falsifiability of the two notions of time. The concept of time as the fourth dimension of space – as a fundamental physical entity in which an experiment occurs – can be falsified by an experiment in which time does not exist, according to the scientists. An example of an experiment in which time is not present as a fundamental entity is the Coulomb experiment; mathematically, this experiment takes place only in space. On the other hand, in the concept of time as a numerical order of change taking place in space, space is the fundamental physical entity in which a given experiment occurs. Although this concept could be falsified by an experiment in which time (measured by clocks) is not the numerical order of material change, such an experiment is not yet known.“Newton theory on absolute time is not falsifiable, you cannot prove it or disprove it, you have to believe in it,” Sorli said. “The theory of time as the fourth dimension of space is falsifiable and in our last article we prove there are strong indications that it might be wrong. On the basis of experimental data, time is what we measure with clocks: with clocks we measure the numerical order of material change, i.e., motion in space.”How it makes senseIn addition to providing a more accurate description of the nature of physical reality, the concept of time as a numerical order of change can also resolve Zeno’s paradox of Achilles and the Tortoise. In this paradox, the faster Achilles gives the Tortoise a head start in the race. But although Achilles can run 10 times faster than the Tortoise, he can never surpass the Tortoise because, for every distance unit that Achilles runs, the Tortoise also runs 1/10 that distance. So whenever Achilles reaches a point where the Tortoise has been, the Tortoise has also moved slightly ahead. Although the conclusion that Achilles can never surpass the Tortoise is obviously false, there are many different proposed explanations for why the argument is flawed.Here, the researchers explain that the paradox can be resolved by redefining velocity, so that the velocity of both runners is derived from the numerical order of their motion, rather than their displacement and direction in time. From this perspective, Achilles and the Tortoise move through space only, and Achilles can surpass Tortoise in space, though not in absolute time.The researchers also briefly examine how this new view of time fits with how we intuitively perceive time. Many neurological studies have confirmed that we do have a sense of past, present, and future. This evidence has led to the proposal that the brain represents time with an internal “clock” that emits neural ticks (the “pacemaker-accumulator” model). However, some recent studies have challenged this traditional view, and suggest that the brain represents time in a spatially distributed way, by detecting the activation of different neural populations. Although we perceive events as occurring in the past, present, or future, these concepts may just be part of a psychological frame in which we experience material changes in space.Finally, the researchers explain that this view of time does not look encouraging for time travelers.“In our view, time travel into the past and future are not possible,” Sorli said. “One can travel in space only, and time is a numerical order of his motion.” Citation: Scientists suggest spacetime has no time dimension (2011, April 25) retrieved 18 August 2019 from https://phys.org/news/2011-04-scientists-spacetime-dimension.html More information: Physicists investigate lower dimensions of the universe 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 two recent papers (one published and one to be published) in Physics Essays, Amrit Sorli, Davide Fiscaletti, and Dusan Klinar from the Scientific Research Centre Bistra in Ptuj, Slovenia, have described in more detail what this means. No time dimensionThey begin by explaining how we usually assume that time is an absolute physical quantity that plays the role of the independent variable (time, t, is often the x-axis on graphs that show the evolution of a physical system). But, as they note, we never really measure t. What we do measure is an object’s frequency, speed, etc. In other words, what experimentally exists are the motion of an object and the tick of a clock, and we compare the object’s motion to the tick of a clock to measure the object’s frequency, speed, etc. By itself, t has only a mathematical value, and no primary physical existence.This view doesn’t mean that time does not exist, but that time has more to do with space than with the idea of an absolute time. So while 4D spacetime is usually considered to consist of three dimensions of space and one dimension of time, the researchers’ view suggests that it’s more correct to imagine spacetime as four dimensions of space. In other words, as they say, the universe is “timeless.”“Minkowski space is not 3D + T, it is 4D,” the scientists write in their most recent paper. “The point of view which considers time to be a physical entity in which material changes occur is here replaced with a more convenient view of time being merely the numerical order of material change. This view corresponds better to the physical world and has more explanatory power in describing immediate physical phenomena: gravity, electrostatic interaction, information transfer by EPR experiment are physical phenomena carried directly by the space in which physical phenomena occur.”As the scientists added, the roots of this idea come from Einstein himself.“Einstein said, ‘Time has no independent existence apart from the order of events by which we measure it,’” Sorli told PhysOrg.com. “Time is exactly the order of events: this is my conclusion.” Explore further Amrit Sorli, Davide Fiscaletti, and Dusan Klinar. “Replacing time with numerical order of material change resolves Zeno problems of motion.” Physics Essays, 24, 1 (2011). DOI: 10.4006/1.3525416Amrit Sorli, Dusan Klinar, and Davide Fiscaletti. “New Insights into the Special Theory of Relativity.” Physics Essays 24, 2 (2011). To be published.last_img read more

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Researchers show bacteria use natural materials to transfer electrons

first_imgGeobacter grows on an electrode. The bacteria feeds on electrons, enabling it to “breathe in” carbon dioxide and “exhale” fuels. Image credit: UMass, Geobacter.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. Researchers discover how bacteria can immobilize uranium Journal information: Proceedings of the National Academy of Sciences Explore further Citation: Researchers show bacteria use natural materials to transfer electrons (2012, June 6) retrieved 18 August 2019 from https://phys.org/news/2012-06-bacteria-natural-materials-electrons.htmllast_img read more

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MIT team shows system that tracks people through walls

first_imgThe IDG News Service video noted a few drawbacks in the system as-is. It can only track one person at a time; the rest of the area needs to be completely clear of movement. Another item on the to-do list is to make the system more compact. Zach Kabelac, masters student, said in the IDG News Service video that “We can put a lot more work into miniaturizing the hardware. The antennas don’t need to be as far apart as they are now. We can bring these closer together to the size of a Kinect, possibly smaller—in the process lose a little bit of accuracy but compared to the gains our system provides, it’s minimal.”The group recently filed a patent, although there are no immediate plans for commercialization. © 2013 Phys.org (Phys.org) —A team of researchers at MIT have been working this year on a system that can track people through walls with impressive accuracy using radio waves. The team showed the system earlier this month. IDG News Service made a video of the demo, which took place at MIT’s Computer Science and Artificial Laboratory (CSAIL) in Cambridge, Massachusetts. The system is still in a proof of concept stage but the team spoke with reps from wireless and component companies during an open house recently. The system was developed by Professor and CSAIL Principal Investigator Dina Katabi and PhD student Fadel Adib. The technology uses low-power signals to track human movement and to decipher motions behind walls. Adib said their accuracy is higher than even state of the art Wi-Fi localization. The approach involves three radio antennas—two transmitting and one receiving, pointed at a wall. In the demo, a person walked around the room on the other side of the wall. The system represented that person as a red dot on a computer screen. and could place the person on the other side of the wall n MIT project can track a user with an accuracy of +/- 10 centimeters. Earlier this year, another report from MIT that was following the CSAIL project’s progress, noted that while researchers have long attempted to build a device capable of seeing people through walls, previous efforts involved expensive and bulky radar technology. The system at MIT uses low-cost technology. The goal is to come up with a device that is low-power, portable and simple enough for use to see through walls and closed doors.Possible scenarios making use of such a system include law enforcement, to avoid personnel walking into an ambush; hostage standoffs; emergency responders trying to see through collapsed structures; and gaming. In addition, the system could be put to use for everyday needs in monitoring children and the elderly. More information: people.csail.mit.edu/fadel/wivi/design.htmlwww.itworld.com/hardware/37824 … h-walls-x-ray-vision Low-power Wi-Fi signal tracks movement—even behind walls Explore further Citation: MIT team shows system that tracks people through walls (2013, October 16) retrieved 18 August 2019 from https://phys.org/news/2013-10-mit-team-tracks-people-walls.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

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Researchers find storm periodicity in southern oceans

first_imgCredit: Tiago Fioreze / Wikipedia Citation: Researchers find storm periodicity in southern oceans (2014, February 7) retrieved 18 August 2019 from https://phys.org/news/2014-02-storm-periodicity-southern-oceans.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. Explore further Future weather conditions are hard to predict due in part to their seemingly random nature, but one part of the world may not be as random as has thought. In this new effort, the research duo pulled out atmospheric data (from balloons, surface temperature readings and satellite observations) relevant to southern hemispheric oceans, covering the past thirty years. In so doing, they focused primarily on circulation of large atmospheric events in the middle latitudes over the southern oceans. That led them to the discovery of a near rhythmic flow of heat as it was carried from the tropical regions into the colder mid-latitudes. That flow, they noted, tended to cause an imbalance in atmospheric conditions that led to the development of storms. It happens, they report, over and over, with storms occurring roughly every 20 to 30 days.Atmospheric scientists have long known about tropic based circulation patterns—so well-known are they that some of them have names, such as the Quasi-Biennial or Madden-Julian Oscillation. What’s surprising is that such circulation patterns are apparently indirectly impacting weather patterns in the mid-latitudes in the south—so much so that the weather there has become periodic as a result. At least as startling, perhaps, is that no one until now has noticed this weather system—at least not in the scientific community—anecdotal evidence suggests sailors have known about it for years.The team used what they had learned to build a computer model to simulate the conditions that were evident in the data record and found the same result, which they suggest means that storms really do follow a periodic pattern in the oceanic part of the Southern Hemisphere—a finding that could prove invaluable for weather forecasters in South America, Africa, Australia or even Antarctica. (Phys.org) —A pair of researchers with the Department of Atmospheric Science at Colorado State University has found that storms in the Southern Hemisphere tend to occur on a 20 to 30 day periodic basis. In their paper published in the journal Science, David Thompson and Elizabeth Barnes describe how they analyzed thirty years of atmospheric data and used it to create a weather model that revealed the periodic behavior of weather patterns in the Southern Hemisphere.center_img Journal information: Science More information: Periodic Variability in the Large-Scale Southern Hemisphere Atmospheric Circulation, Science 7 February 2014: Vol. 343 no. 6171 pp. 641-645. DOI: 10.1126/science.1247660AbstractPeriodic behavior in the climate system has important implications not only for weather prediction but also for understanding and interpreting the physical processes that drive climate variability. Here we demonstrate that the large-scale Southern Hemisphere atmospheric circulation exhibits marked periodicity on time scales of approximately 20 to 30 days. The periodicity is tied to the Southern Hemisphere baroclinic annular mode and emerges in hemispheric-scale averages of the eddy fluxes of heat, the eddy kinetic energy, and precipitation. Observational and theoretical analyses suggest that the oscillation results from feedbacks between the extratropical baroclinicity, the wave fluxes of heat, and radiative damping. The oscillation plays a potentially profound role in driving large-scale climate variability throughout much of the mid-latitude Southern Hemisphere. © 2014 Phys.org Changing atmospheric circulation over North Atlantic less likely to steer Sandy-like storms into the US coastlast_img read more

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Researchers suggest Little Foot is an entirely new species of early human

first_img © 2018 Science X Network Citation: Researchers suggest ‘Little Foot’ is an entirely new species of early human (2018, December 10) retrieved 18 August 2019 from https://phys.org/news/2018-12-foot-species-early-human.html South African skeleton shows humans learned to walk upright in the trees 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 curved left forearms bones of the StW 573 Australopithecus skeleton shown with superior toward the top of the image. The ulna (left) is near-lateral view and radius (right) is in anterior view. Credit: Bilateral Asymmetry of the Forearm Bones as Possible Evidence of Antemortem Trauma in the StW 573 Australopithecus Skeleton from Sterkfontein Member 2 (South Africa), The skeleton first became known when Ronald Clarke of the University of Witwatersrand looked through a bone collection back in the 1990s—he came across foot bones that were labeled as monkey bones. After determining that they were not ape, he and colleagues ventured to the Sterkfontein caves near Johannesburg in 1994, where the bones had been found, and began digging. Because of the challenges involved, it took the team approximately 10 years to fully extricate the skeleton from the rock in which it was embedded. It took another 10 years to fully clean and study the skeleton. Four teams with ties to Clarke have written papers describing aspects of the skeleton, all of which conclude that it represents a unique species. Clarke and his team have therefore given it a name: Australopithecus Prometheus. The researchers are offering some details of their findings as their papers make their way first onto bioRxiv, and then presumably into a journal.The researchers report that the skeleton was from an elderly woman with an arm bowed due to injury. They also report that the woman would have stood just over four feet tall and had legs that were longer than her arms—a hallmark of bipedalism. She was also vegetarian. The details regarding the skeletal remains have been released prior to publication because other groups have recently been granted access to the remains, and the original team does not want to be scooped.The researchers have told the press that Little Foot’s face is flatter than the faces of members of A. africanus (which includes Lucy). There are also other differences in skull shape and tooth arrangement and size. They suggest differences in the hip bone alone are enough to support their claim that Little Foot is a new species. More information: Robin Huw Crompton et al. Functional Anatomy, Biomechanical Performance Capabilities and Potential Niche of StW 573: an Australopithecus Skeleton (circa 3.67 Ma) From Sterkfontein Member 2, and its significance for The Last Common Ancestor of the African Apes and for Hominin Origins, (2018). DOI: 10.1101/481556 Ronald J Clarke et al. The skull of StW 573, a 3.67 Ma Australopithecus skeleton from Sterkfontein Caves, South Africa, (2018). DOI: 10.1101/483495 Laurent Bruxelles et al. A multiscale stratigraphic investigation of the context of StW 573 Little Foot and Member 2, Sterkfontein Caves, South Africa, (2018). DOI: 10.1101/482711 A.J. Heile et al. Bilateral Asymmetry of the Forearm Bones as Possible Evidence of Antemortem Trauma in the StW 573 Australopithecus Skeleton from Sterkfontein Member 2 (South Africa), (2018). DOI: 10.1101/486076 Explore further Several teams of researchers have announced that the skeletal remains of a hominin believed to have lived approximately 3.67 million years ago represent a new species of early human. The researchers report that the specimen, known as “Little Foot,” has characteristics that make it unlike any other known species.last_img read more

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Astronomers discover nine new variable stars

first_img Dozens of new variable stars found in a dense globular cluster This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further A team of astronomers from Chile has detected nine new variable stars in the globular cluster NGC 6652 and its background stream. Six of the newly found stars were classified as eclipsing binaries, one as an SX Phoenicis star, and two remain unclassified. The finding is detailed in a paper published December 10 on arXiv.org. Variable stars could offer important hints into aspects of stellar structure and evolution. They could be also helpful for better understanding of the distance scale of the universe.In particular, studies of variable stars in star clusters are of special interest for astronomers as they have the potential to help identify systematic errors that affect stellar distance indicators. However, although stellar variability in globular clusters (GCs) of the Milky Way galaxy is one of the oldest branches of astronomy, there are still many galactic GCs in which the census of their variable star content is far from complete.One such understudied cluster is NGC 6652, residing some 32,600 light-years away from the Earth and about 8,800 light-years from the center of the Milky Way, in front of the Sagittarius dwarf spheroidal galaxy. It is an old (about 11.7 billion years), fairly metal-rich galactic globular cluster associated either with the Milky Way’s inner halo or the outer parts of the bulge.A group of researchers led by Ricardo Salinas of Gemini Observatory in Chile, has conducted a search for variable stars in NGC 6652 and the background Sagittarius stream. They have analyzed archival data from the Gemini Multiobject Spectrograph (GMOS) at the Gemini South telescope, which resulted in finding nine new variable stars.”We conducted a variable star search on the metal-rich galactic globular cluster NGC 6652 using archival Gemini-S/GMOS data. We report the discovery of nine new variable stars in the NGC 6652 field, of which we classify six as eclipsing binaries and one as an SX Phoenicis star, leaving two variables without classification,” the astronomers wrote in the paper. The newly detected variable stars received provisional designation from V15 to V23. V17 is an SX Phoenicis star, while the classification of V15 and V21 is currently unknown. The most interesting find presented in the paper is V17 – a pulsating blue straggler. It is a member of the Sagittarius stream and has a well-defined period of 0.039 days.In general, SX Phoenicis stars like V17 have spectral types between A2 and F5, vary in magnitude by up to 0.7, and short period pulsation behavior varying on timescales from 0.03 to 0.08 days. All known SX Phoenicis variables in GCs are blue straggler stars as they are more luminous and bluer than stars at the main sequence turnoff point for the cluster.When it comes to the six binaries, V16 was found to be a long-period eclipsing binary, V18 a Beta Lyra-type eclipsing binary, and V19 most likely a W Uma type, although a Beta Lyra membership cannot be excluded. According to the researchers, V20 is also most likely of W Uma type, V22 could be a RGB star in an eclipsing system, while V23 is an eclipsing variable of the Algol type. © 2018 Science X Network Citation: Astronomers discover nine new variable stars (2018, December 19) retrieved 18 August 2019 from https://phys.org/news/2018-12-astronomers-variable-stars.html A finding chart for the discovered variables in the NGC 6652 field, based on a GMOS r image. The position of V14 is also indicated. The fov is 5.5′ ×5.5′ . North is up, East to the left. Credit: Salinas et al., 2018. More information: Ricardo Salinas et al. New variable stars in NGC 6652 and its background Sagittarius stream. arXiv:1812.03605 [astro-ph.SR] arxiv.org/abs/1812.03605last_img read more

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