Linguist study finds core group of words has survived for 15000 years

first_imgMap showing approximate regions where languages from the seven Eurasiatic language families are spoken. The color-shaded areas should be treated as suggestive only, as current language rangeswill not necessarily correspond to original homelands, and language boundaries will often overlap. For example, the Indo-European language Swedish is spoken along with the Uralic Finnish in southern Finland. Credit: PNAS doi: 10.1073/pnas.1218726110 Citation: Linguist study finds core group of words has survived for 15,000 years (2013, May 7) retrieved 18 August 2019 from https://phys.org/news/2013-05-linguist-core-group-words-survived.html More information: Ultraconserved words point to deep language ancestry across Eurasia, PNAS, Published online before print May 6, 2013, doi: 10.1073/pnas.1218726110AbstractThe search for ever deeper relationships among the World’s languages is bedeviled by the fact that most words evolve too rapidly to preserve evidence of their ancestry beyond 5,000 to 9,000 y. On the other hand, quantitative modeling indicates that some “ultraconserved” words exist that might be used to find evidence for deep linguistic relationships beyond that time barrier. Here we use a statistical model, which takes into account the frequency with which words are used in common everyday speech, to predict the existence of a set of such highly conserved words among seven language families of Eurasia postulated to form a linguistic superfamily that evolved from a common ancestor around 15,000 y ago. We derive a dated phylogenetic tree of this proposed superfamily with a time-depth of ∼14,450 y, implying that some frequently used words have been retained in related forms since the end of the last ice age. Words used more than once per 1,000 in everyday speech were 7- to 10-times more likely to show deep ancestry on this tree. Our results suggest a remarkable fidelity in the transmission of some words and give theoretical justification to the search for features of language that might be preserved across wide spans of time and geography.Press release Journal information: Proceedings of the National Academy of Sciences More words dying and fewer words being added to languages in digital age: study © 2013 Phys.orgcenter_img Most people realize that all languages are constantly evolving—new words are added and others are lost and some even undergo changes in pronunciation. For that reason, it would seem surprising to find that some commonly used words have survived—albeit in modified form—for as long as perhaps 15,000 years. That’s what the researchers in this new effort have found. They believe that people speaking a single language in early Eurasia used a core group of words that are found in most present-day, subsequently evolving languages.The team acknowledges that most in the field believe that words don’t survive any longer than eight or nine thousand years—there’s just too much “weathering.” But their research shows otherwise.Most language experts agree that a “proto-Eurasiatic” language existed and was spoken by a wide group of people in Europe and parts of Asia thousands of years ago. That language eventually evolved into English, German, Spanish, Italian, etc. Until now however, most in the field have agreed that as the languages matured, words from the old language were lost. The researchers on this new effort disagree, and they say it’s all based on “cognates”—words that have basically the same meaning in different languages and sound similar as well. In this new effort, the research team has been studying cognates and their use in several modern languages. They’ve also been comparing them with the 200 standard words that linguists agree are core to virtually all languages. And finally, they also looked at “proto-words”—words that researchers make up when attempting to define cognates in long-dead languages.After careful analysis and comparison, the researchers arrived at a list of cognates that appear to not only exist in all modern languages that evolved from the proto-Eurasiatic language, but that actually existed in the early language, as well. Put another way, words like “father” or “fish,” or at least their cognate forms, have been in use for at least 15,000 years. (Phys.org) —A team of linguistics experts from the U.S., Great Britain and New Zealand has found evidence that suggests a core group of words used in a common language thousands of years ago has survived to this day. In their paper published in Proceedings of the National Academy of Sciences, the researchers claim that some core words used in modern languages are related to some spoken 15,000 years ago. Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Researchers replicate supershear earthquakes in the lab

first_imgAerial photo of the San Andreas Fault in the Carrizo Plain, northwest of Los Angeles. Credit: Wikipedia. Citation: Researchers replicate supershear earthquakes in the lab (2013, June 7) retrieved 18 August 2019 from https://phys.org/news/2013-06-replicate-supershear-earthquakes-lab.html (Phys.org) —A team of geology researchers working in France has for the first time recreated the conditions in a lab that lead to a phenomenon known as a supershear earthquake. In their paper published in the journal Science, the researchers describe how they found that compressing granite under certain conditions caused ruptures to propagate faster than shear waves leading to an observable supershear event. Explore further Earthquake acoustics offer hint that a tsunami is imminent, researchers find More information: From Sub-Rayleigh to Supershear Ruptures During Stick-Slip Experiments on Crustal Rocks, Science 7 June 2013: Vol. 340 no. 6137 pp. 1208-1211 DOI: 10.1126/science.1235637ABSTRACTSupershear earthquake ruptures propagate faster than the shear wave velocity. Although there is evidence that this occurs in nature, it has not been experimentally demonstrated with the use of crustal rocks. We performed stick-slip experiments with Westerly granite under controlled upper-crustal stress conditions. Supershear ruptures systematically occur when the normal stress exceeds 43 megapascals (MPa) with resulting stress drops on the order of 3 to 25 MPa, comparable to the stress drops inferred by seismology for crustal earthquakes. In our experiments, the sub-Rayleigh–to–supershear transition length is a few centimeters at most, suggesting that the rupture of asperities along a fault may propagate locally at supershear velocities. In turn, these sudden accelerations and decelerations could play an important role in the generation of high-frequency radiation and the overall rupture-energy budget.center_img In a “normal” earthquake, seismic waves are generated as a result of faults in the Earth’s crust that rupture. At the same time, deep within the Earth, shear waves are generated that also propagate but are not felt on the surface. Shear waves tend to move much faster than seismic waves. Sometimes, though, in very rare instances, seismic waves gain a boost in speed and wind up propagating faster than sheer waves. The result is what geologists call a sonic-boom type of earthquake that can be far worse than its magnitude would indicate. Supershear earthquakes have been recorded occurring in nature just a few times, but until now have never been reproduced in the lab.To recreate the special conditions that lead to a supershear earthquake, the researchers subjected slabs of granite to very high pressure—pushing them together while also applying sideways pressure until they slipped against one another—releasing a wave of energy. It’s the same type of experiment used to study various types of earthquake conditions. In this instance, the researchers replicated the experiment 200 times—each time taking careful measurements with acoustic sensors. The team found that by manipulating the pressure exerted they could induce supershear like conditions. Their experiment was the first ever to succeed in recreating a supershear earthquake-like event in the lab. More importantly, it also shows that supershear earthquakes can occur at a much smaller level than researchers had believed. This means, they say, that such earthquakes should be able to occur much more often in the real world.The results obtained by the researchers aren’t a sign that people should worry, however, because it’s quite possible that the conditions in the lab were optimal for the creation of supershear earthquakes, most specifically the presence of smooth even granite surfaces—this is generally not the case in nature, and likely why they occur so seldom in the real world. The researchers suggest it’s possible that many supershear earthquakes happen in nature, but we don’t know about them because they occur in sections of faults that don’t move. © 2013 Phys.org Journal information: Science 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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Some monkeys can understand danger calls made by different monkey species

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. Human beings are the only species known to have a complete language, though other animals make sounds that can be interpreted by others of their species, and now it appears that at least in one case, the sounds made by one species can be interpreted by members of another. In this new effort focusing on the communication skills of monkeys the researchers looked to Campbell’s and Diana monkeys living in the Ivory Coast.Prior research has found that male Campbell’s monkeys use at least six unique sounds to convey information to their group members. Two of those “krak” and “krak-oo” have been found to be variations of the same idea—there is a threat at hand. Krak is more specific however, it means that a leopard is nearby whereas adding that oo suffix waters it down to meaning there is some threat, but it is not a leopard. Because Diana monkeys live in the same places as Campbell’s monkeys, the team wondered if they were able to understand the danger calls of the Campbell’s. To find out, they made recordings of Campbell’s monkey calls, and edited some of them—adding or removing the oo suffix. Then, they took the recordings into the jungle and played them in the vicinity of Diana monkeys and watched to see how they responded.The team found that the Diana monkeys reacted to the Campbell’s monkey calls in a manner almost identical to other Campbell’s monkeys—they grew much more agitated when hearing the krak call then when hearing the krak—oo call, and remained on alert longer, which the team claims proves that the Diana monkeys were able to differentiate between the two and to respond accordingly. Explore further Citation: Some monkeys can understand danger calls made by different monkey species (2015, April 29) retrieved 18 August 2019 from https://phys.org/news/2015-04-monkeys-danger-monkey-species.html More information: Suffixation influences receivers’ behaviour in non-human primates, Proceedings of the Royal Society B, Published 29 April 2015. DOI: 10.1098/rspb.2015.0265AbstractCompared to humans, non-human primates have very little control over their vocal production. Nonetheless, some primates produce various call combinations, which may partially offset their lack of acoustic flexibility. A relevant example is male Campbell’s monkeys (Cercopithecus campbelli), which give one call type (‘Krak’) to leopards, while the suffixed version of the same call stem (‘Krak-oo’) is given to unspecific danger. To test whether recipients attend to this suffixation pattern, we carried out a playback experiment in which we broadcast naturally and artificially modified suffixed and unsuffixed ‘Krak’ calls of male Campbell’s monkeys to 42 wild groups of Diana monkeys (Cercopithecus diana diana). The two species form mixed-species groups and respond to each other’s vocalizations. We analysed the vocal response of male and female Diana monkeys and overall found significantly stronger vocal responses to unsuffixed (leopard) than suffixed (unspecific danger) calls. Although the acoustic structure of the ‘Krak’ stem of the calls has some additional effects, subject responses were mainly determined by the presence or the absence of the suffix. This study indicates that suffixation is an evolved function in primate communication in contexts where adaptive responses are particularly important. (Phys.org)—A team of researchers with members from France, Ivory Coast, Switzerland and the U.K. has found that some monkeys of one species are able to listen in and respond to communications made by monkeys of another species. In their paper published in Proceedings of the Royal Society B, the researchers describe a field study they conducted with two monkey species and what they learned from it.center_img Journal information: Proceedings of the Royal Society B Credit: cordis.europa.eu © 2015 Phys.org Linguistic methods uncover sophisticated meanings, monkey dialectslast_img read more

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Dark matter hiding in stars may cause observable oscillations

first_imgIn previous research on dark matter stars, it has often been assumed that stars accreting dark matter will continue to grow until they become so dense that they collapse into black holes. However, in the new study the physicists’ simulations showed that these stars actually appear to be stable and do not become black holes. Their stability arises from a self-regulatory mechanism called “gravitational cooling” in which the stars eject mass to slow down and stop their growth before they approach the critical Chandrasekhar limit, the point at which they collapse into black holes. As the scientists explain, the finding that dark matter stars are stable makes a surprising contribution to the research in this area.”Although it was known for some time that dark matter can be accreted by stars and form dark matter cores at their center, those studies were all phenomenological,” Brito said. “In addition, basically all these studies suggested that, if enough dark matter is accreted by a star, it will eventually trigger gravitational collapse and a black hole would form, eventually eating all the star.”We set about checking these claims, using a rigorous fully relativistic framework, i.e., solving the full Einstein’s equations. This is important if we want to understand how the dark matter core behaves for large densities. Well, it turns out that our results show that black hole formation can, in principle, be avoided by ejecting excessive mass: the dark matter core starts ‘repelling’ itself when it is too massive and compact, and is unable to grow past a certain threshold. This is, as far as we know, something that was ignored in previous works. “The above results are quite generic. Because any self-gravitating massive bosonic field can form compact structures, any such putative dark matter component would lead to the kind of effects we discuss in our paper. In this sense it proposes another way to search for these kinds of particles that can be complementary to observations coming from cosmology, for example. Given the lack of information that we have about the nature of dark matter, we think that it might be worth the effort to further develop this subject.”The scientists hope that the results here may help guide future research by suggesting where to look for dark matter and what methods to use to detect it.”We don’t know much about dark matter,” Brito said. “The only thing we do know is that all kinds of matter (be it regular matter or dark, invisible matter) fall in the same way in gravitational fields. This is Einstein’s equivalence principle in action. Thus, dark matter also falls in the usual way. It seems therefore appropriate to look for effects of dark matter in regions where gravity is strong, like neutron stars, black holes, etc. We are now trying to understand how dark matter behaves generically in regions of strong gravity.”At this precise moment, we are working on a long version of this letter. We want to understand in depth how the dark matter core grows for different kind of scenarios, and how viscosity in the star’s material affects the development of the accretion process.” (Phys.org)—Dark matter has never been seen directly, but scientists know that something massive is out there due to its gravitational effects on visible matter. One explanation for how such a large amount of mass appears to be right in front of our eyes yet completely invisible by conventional means is that the dark matter is hiding in the centers of stars. This sequence shows snapshots of a star’s density when two dark matter cores collide, where the x-axis is the plane of collision (only half the space is shown, but the remaining space can be obtained by symmetry). Although the final configuration is more compact and massive than the original, the star does not collapse into a black hole because it ejects some of its mass, slowing down its growth so that it remains stable. Credit: Brito, et al. ©2015 American Physical Society Dark matter guides growth of supermassive black holes In a new study, physicists have investigated the possibility that large amounts of hidden mass inside stars might be composed of extremely lightweight hypothetical particles called axions, which are a primary dark matter candidate. The scientists, Richard Brito at the University of Lisbon in Portugal; Vitor Cardoso at the University of Lisbon and the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada; and Hirotada Okawa at Kyoto University and Waseda University, both in Japan, have published their paper on dark matter in stars in a recent issue of Physical Review Letters.”Our work studies how dark matter piles up inside stars if the dark matter is composed of massive bosonic particles (axions are an example of such particles),” Brito told Phys.org. “Our results show that dark matter accretion by stars does not lead to gravitational collapse; instead it may give rise to characteristic vibrations in stars.” The researchers theoretically showed that, if numerous axions were to pile up inside normal stars, then the dark matter core would oscillate. The oscillating core would in turn cause the star’s fluid to oscillate in tune with it at a specific frequency related to the star’s mass, or at multiples of this frequency. For a typical axion mass, the oscillating stars would emit microwave radiation and might have observable effects.”What oscillates is the fluid density and its pressure, but it’s probably correct as well to say that the entire star is oscillating,” Brito explained. “These are like sound waves propagating through the fluid, with a very specific frequency. Oscillations of this kind could, for example, lead to variations in the luminosity or in the temperature of the star, and these are quantities that we can measure directly.”In fact, there is already a whole branch of physics called asteroseismology, which studies the internal structure of stars by observing their oscillation modes. This is very much like the way scientists study the internal structure of the Earth by looking at seismic waves. It is possible that the oscillations of a star driven by a dark matter core could also be observed using similar methods. Given the very specific frequencies at which these stars would vibrate, this could be a smoking gun for the presence of dark matter. Asteroseismology is still in its infancy but it will, almost certainly, become a very precise way of observing stars in the future.” © 2015 Phys.org More information: Richard Brito, Vitor Cardoso, and Hirotada Okawa. “Accretion of dark matter by stars.” Physical Review Letters. DOI: 10.1103/PhysRevLett.115.111301, Also at arXiv:1508.04773 [gr-qc] Citation: Dark matter hiding in stars may cause observable oscillations (2015, September 18) retrieved 18 August 2019 from https://phys.org/news/2015-09-dark-stars-oscillations.html Explore further Journal information: Physical Review Letters 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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An idea for allowing the human eye to observe an instance of

first_imgScheme of the proposal for detecting entanglement with the human eye. Credit: arXiv:1602.01907 [quant-ph] Explore further More information: What does it take to see entanglement? arXiv:1602.01907 [quant-ph] arxiv.org/abs/1602.01907AbstractTremendous progress has been realized in quantum optics for engineering and detecting the quantum properties of light. Today, photon pairs are routinely created in entangled states. Entanglement is revealed using single-photon detectors in which a single photon triggers an avalanche current. The resulting signal is then processed and stored in a computer. Here, we propose an approach to get rid of all the electronic devices between the photons and the experimentalist i.e. to use the experimentalist’s eye to detect entanglement. We show in particular, that the micro entanglement that is produced by sending a single photon into a beam-splitter can be detected with the eye using the magnifying glass of a displacement in phase space. The feasibility study convincingly demonstrates the possibility to realize the first experiment where entanglement is observed with the eye.via TechnologyReview 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. Physicists have learned how to restore the entanglement of ‘untangled’ quantum light Journal information: arXivcenter_img © 2016 Phys.org Entanglement, is of course, where two quantum particles are intrinsically linked to the extent that they actually share the same existence, even though they can be separated and moved apart. The idea was first proposed nearly a century ago, and it has not only been proven, but researchers routinely cause it to occur, but, to date, not one single person has every actually seen it happen—they only know it happens by conducting a series of experiments. It is not clear if anyone has ever actually tried to see it happen, but in this new effort, the research trio claim to have found a way to make it happen—if only someone else will carry out the experiment on a willing volunteer.The idea involves using a beam splitter and two beans of light—an initial beam of coherent photons fired at the beam splitter and a secondary beam of coherent photons that interferes with the photons in the first beam causing a change of phase, forcing the light to be reflected rather than transmitted. In such a scenario, the secondary beam would not need to be as intense as the first, and could in fact be just a single coherent photon—if it were entangled, it could be used to allow a person to see the more powerful beam while still preserving the entanglement of the original photon.The researchers suggest the technology to carry out such an experiment exists today, but also acknowledge that it would take a special person to volunteer for such an assignment because to prove that they had seen entanglement taking place would involve shooting a large number of photons in series, into a person’s eye, whereby the resolute volunteer would announce whether they had seen the light on the order of thousands of times. Citation: An idea for allowing the human eye to observe an instance of entanglement (2016, February 18) retrieved 18 August 2019 from https://phys.org/news/2016-02-idea-human-eye-instance-entanglement.html (Phys.org)—A trio of physicists in Europe has come up with an idea that they believe would allow a person to actually witness entanglement. Valentina Caprara Vivoli, with the University of Geneva, Pavel Sekatski, with the University of Innsbruck and Nicolas Sangouard, with the University of Basel, have together written a paper describing a scenario where a human subject would be able to witness an instance of entanglement—they have uploaded it to the arXiv server for review by others.last_img read more

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What Would a Dog Do on Mars

first_imgRecently, NASA released colorful, dreamy illustrations depicting an imagined future in which human beings have made it to other worlds. A curly-haired astronaut floats inside a lunar space station, with the crater-pocked moon behind her. A lunar explorer steadies a camera on a tripod to photograph Earth in the distance. And an astronaut stands on the dunes of Mars with her hands in the pockets of her spacesuit, a dog at her side. But dogs have been to space. In the 1950s and 1960s, the Soviet Union strapped dogs into capsules and launched them into the sky. The canines were not trusty space sidekicks, but research subjects, strays collected from city streets to test launch systems before humans themselves did. (The United States conducted similar tests, with several species of monkeys.) Read the whole story: The Atlantic Wait, a dog?center_img To be clear, NASA’s ambitious plans for missions to the moon and Mars do not include dogs. (At least, none that the public knows about. If you’re a member of a top-secret program to groom doggonauts, please contact me.) The agency does want to send humans there, sometime in the 2030s.last_img read more

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Democracy net tax crisis get Hungarians to protest

first_imgIt was by far the largest protest since his center-right government took power in 2010 and pursued moves to redefine many walks of life, drawing accusations of creeping authoritarianism, although it was re-elected by a landslide this year. Orban’s government has imposed special taxes on the banking, retail, energy and telecommunications sectors to keep the budget deficit in check, jeopardizing profits in some parts of the economy and unnerving international investors. The internet data levy idea was first floated in the 2015 tax code submitted to the Central European country’s parliament last week, triggering objections from internet service providers and users who felt it was anti-democratic. The crowd, which was organized by a Facebook-based social network and appeared to draw mostly well-heeled professionals, marched through central Budapest demanding the repeal of the planned tax and the ouster of Orban. Many protesters held up makeshift signs that read ‘ERROR!’ and ‘How many times do you want to skin us?’ Zsolt Varady, an internet entrepreneur and founder of a now-defunct Hungarian social network iwiw.hu, told the crowd that the tax threatened to undermine internet freedoms. ‘Between 2006 and 2006 iwiw motivated many people to get an internet subscription,’ Varady said. ‘People were willing to pay for the service because they knew, saw and felt that their lives were becoming better… The internet tax threatens the further growth of the Internet as well as freedom of information.’ Tax reduced after first protest. The government had planned to tax internet data transfers at a rate of 150 forints per gigabyte. After analysts calculated this would total more than the sector’s annual revenue and an initial protest drew thousands on Sunday, Fidesz submitted a bill that capped the tax at 700 forints per month for individuals and 5,000 forints for companies. That did not placate Tuesday’s protesters. ‘I am a student, my parents are not well off, neither am I, so I work hard,’ said Ildiko Pirk, a 22-year-old studying nursing. ‘I doubt the internet companies won’t build this tax into their prices. And I have a computer, a smartphone, as does my mother and my four siblings… That adds up.’ She said the internet was vital for her to get the books she needs for her studies but also to read unbiased news that is not under the control of Hungary’s ruling political elite. She and other protesters said the government’s other moves also bothered them, such as a perceived mismanagement of the economy and a recent dispute with the United States over alleged corruption of Hungarian public officials. The Orban government denied any anti-democratic agenda, saying it aimed only to get all economic sectors to share the tax burden and was tapping into a trend of telecommunications shifting away from already-taxed telephony and text messages.last_img read more

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Promotion of equilibrium in society the need of the hour

first_imgKolkata: The biggest challenge before India is its unequal development of the country and the only way it can be addressed is by promoting equilibrium in society, Piyush Goyal, Union minister for Railways, Coal, Finance & Corporate Affairs, said on Monday.”Mutual trust and consensus is a key area for ensuring success of GST in a federal structure like India”, he said.Speaking at an exclusive interactive session organised by the Indian Chamber of Commerce at a city hotel, Goyal elaborated on the “Vision for 2022” for India and the role that all sections of the society, including industry and industry associations, can play in fructifying the objective of attaining development for all. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedGoyal felt that the government and industry can join hands to effectively reach out to the developmental needs of the bottom of the pyramid through meaningful and well strategised CSR initiatives, in particular for the 115 identified aspirational districts of India.He mentioned that though India has made rapid strides in many sectors post-independence, significant room for progress still remains.He justified the fact that one single uniform GST tax rate is not tenable for India, as it would nullify the very concept of progressive taxation and the tenets of equitable distribution of income. Also Read – Naihati: 10 councillors return to TMC from BJPFocussing on the rapid development witnessed in India over the past 4 years of the Modi regime, Goyal termed the single most important factor of change as the “change in mindset,” which has led to monumental changes in infrastructure, connectivity, macro economy and human capital development in the country, to name a few.He spoke on the important changes being brought about in energy efficiency, distribution and transmission in the power sector in India. He spoke of the government’s commitment to provide rural electrification and ensure availability of LPG and subsequently solar-powered cookers for all households in the country, including the remotest corners.Goyal reiterated that augmented MSP for farm produce would not impact the fiscal deficit, as defaults on loans would have directly led to increased NPAs and affected billions of people engaged in farming in the country.Shashwat Goenka, president, Indian Chamber of Commerce, gave the welcome address, calling Goyal a “thought provoking and dynamic leader”.Rudra Chatterjee, senior vice-president, Indian Chamber of Commerce, offered the formal vote of thanks.last_img read more

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Teenage night owls at high obesity risk

first_imgIf your teenage kid loves to spend night time with gadgets, ask him or her to reduce this habit as this may make him fat in just five years’ time.According to research, teenagers and adults who go to bed late on weeknights are more likely to gain weight than their peers who hit the hay earlier.“The results highlight adolescent bed times, not just total sleep time, as a potential target for weight management during the transition to adulthood,” said Lauren Asarnow, lead author and doctoral student in University of California-Berkeley. Also Read – ‘Playing Jojo was emotionally exhausting’For this, the researchers analysed data from a nationally representative cohort of more than 3,300 youths and adults. They found that for every hour of sleep they lost, they gained 2.1 points on the body mass index (BMI). This gain occurred roughly over a five-year period.The results show that many teenagers do not get the recommended nine hours sleep a night and report having trouble staying awake at school.The human circadian rhythm, which regulates physiological and metabolic functions, typically shifts to a later sleep cycle at the onset of puberty.The results suggest that adolescents who go to bed earlier will “set their weight on a healthier course as they emerge into adulthood”, Asarnow added. The paper appeared in the journal Sleep.last_img read more

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People who care for others may live longer

first_imgOlder people who help and support others may live longer than those who do not, a new study has claimed.Researchers, including those from Max Planck Institute for Human Development in Germany, conducted survival analyses of over 500 people aged between 70 and 103 years, drawing on data collected between 1990 and 2009.The researchers compared grandparents who provided occasional childcare with those who did not, as well as with older adults who did not have children or grandchildren but who provided care for others in their social network. Also Read – Add new books to your shelfThe results of their analyses show that this kind of care-giving can have a positive effect on the mortality of the carers.Half of the grandparents who took care of their grandchildren were still alive about ten years after the first interview in 1990.The same applied to participants who did not have grandchildren, but who supported their children – for example, by helping with housework. In contrast, about half of those who did not help others died within five years. Also Read – Over 2 hours screen time daily will make your kids impulsiveThe researchers were also able to show that this positive effect of care-giving on mortality was not limited to help and care-giving within the family. The data analysis showed that childless older adults who provided others with emotional support, for example, also benefited.Half of these helpers lived for another seven years, whereas non-helpers on average lived for only another four years. “But helping should not be misunderstood as a panacea for a longer life,” said Ralph Hertwig from Max Planck Institute for Human Development.“A moderate level of care-giving involvement does seem to have positive effects on health. But previous studies have shown that more intense involvement causes stress, which has negative effects on physical and mental health,” said Hertwig.As it is not customary for grandparents in Germany and Switzerland to take custodial care of their grandchildren, primary and custodial caregivers were not included in the analyses. Researchers think that prosocial behaviour was originally rooted in the family.“It seems plausible that the development of parent’s and grandparent’s prosocial behaviour toward their kin left its imprint on the human body in terms of a neural and hormonal system that subsequently laid the foundation for the evolution of cooperation and altruistic behaviour towards non-kin,” said Sonja Hilbrand from the University of Basel in Switzerland.The study was published in the journal Evolution and Human Behaviour.last_img read more

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