Photo: Christian Mundigler 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. Oldest written document ever found in Jerusalem (PhysOrg.com) — In a study to be published this month in the Proceedings of the Athens Archaeological Society, archaeologist Michael Cosmopoulos of the University of Missouri-St. Louis shares his discovery of a clay tablet showing the earliest known writing in Europe. Located in the southwestern corner of Greece, the town where this discovery took place is Iklaina. This town dates back to the Mycenaean period of 1500 BC to 100 BC, and around 1400 BC was conquered by King Nestor.Cosmopoulos has been actively excavating this site for 11 years and has found evidence of a Mycenaean palace, including colorful murals, Cyclopean walls, and an elaborate drainage system made from clay pipes. However, this tablet has been his most unexpected find.Tablets of this nature were made from clay which was allowed to dry in the sun, making them very brittle and easily destroyed. The tablet they discovered however, had been thrown in a garbage pit and burned, thus firing the clay and leaving it preserved.The estimated 3,500 year-old tablet only measures around one inch by one and a half inches, but shows various symbols of Linear B, an ancient Greek writing consisting of 87 signs, each signifying one syllable. It appears that the Mycenaean’s used this tablet to record economic matters of interest to those in the ruling party. From what the researchers can distinguish, the front of the tablet shows markings appearing to for a verb relating to manufacturing. The back of this small tablet shows a list with numbers and names.While this is not the oldest writing ever found, it is the earliest example of writing found in Europe. Writing found in China, Egypt, and Mesopotamia is believed to date back to 3,000 BC.Originally believed that such tablets were only found in major state capitals or the time period, this find brings to that they were also used in what are considered second-tier towns. Researchers are hoping this find will help to shed some light on how these ancient Greek kingdoms were run. © 2010 PhysOrg.com More information: www.archetai.gr/site/eng_page_uc.html Citation: Oldest evidence of writing found in Europe (2011, April 4) retrieved 18 August 2019 from https://phys.org/news/2011-04-oldest-evidence-europe.html Explore further
Each system works by making use of embedded sensors – physical devices that are embedded in the roadway, parking lot or other parking sites. Information from the sensors, care of Cisco, is routed to a cloud based facility where data can then be disseminated to drivers via smartphone using the Streetline app, Parker.The app allows drivers to actually see, in real-time, where available spaces are located on a map. Once they’ve chosen which one they’d like to use, the app then offers a hands-free navigational assist to help them get there as quickly as possible. Parker also shows pricing and the time frame during which parking spots are available for use. Also, users can tell the system where they’d like to go, to a movie theater, for example, and Parker will display parking lots or garages in the vicinity. And for those that sometimes forget where they parked their car, Parker allows their spot to be pinned to a map as they leave their vehicle.Some of the networks use sensors embedded in parking meters, most of the rest are installed by drilling a golf ball sized hole in the pavement and pasting it in place. The top of the sensor is exposed and lies even with the pavement, allowing for measuring light changes or the actual presence of a vehicle using a magnetometer. Information from each sensor is sent to a Cisco WiFi mesh network which optimizes the most efficient path to the cloud via a control box located in a central nearby facility. The Parker app is available for both iOS and Android devices. IBM looks to take pain out of parking © 2012 Phys.org (Phys.org)—A partnership between smart parking solutions provider Streetline, Inc. and Cisco has resulted in the implementation of WiFi networking systems based on embedded sensors and a smart phone app currently being used in several major cities in the United States. The system is expected to reduce the amount of time drivers spend looking for parking spaces and to increase the amount of revenue cities are able to get from motorists paying to park. The partnership has already led to networks being installed in several California cities as well as in Washington D.C., Knoxville TN, Reno NV and Fort Lauderdale, FL. Citation: Partnership bringing real-time parking information to urban motorists (2012, December 5) retrieved 18 August 2019 from https://phys.org/news/2012-12-partnership-real-time-urban-motorists.html Explore further More information: www.theparkerapp.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.
Explore further More information: console-cowboys.blogspot.com/2 … -dvr-insecurity.htmlwww.forbes.com/sites/andygreen … to-hacker-hijacking/community.rapid7.com/community … etrieval-remote-root (Phys.org)—A digital video recorder (DVR), used in homes and businesses for security, is helpful when not in the hands of criminals, The latter scenario is what is rattling some security blog and Forbes readers, with the recent Forbes report by Andy Greenberg of how criminals are capable of hijacking security cameras. Once in control, surveillance camera footage can be played back, copied, deleted, or changed. The hijackers can also use the machines to access other computers behind the victim’s firewall. Citation: Uninvited access to security camera systems pinned down (2013, January 29) retrieved 18 August 2019 from https://phys.org/news/2013-01-uninvited-access-camera-pinned.html Apricorn Announces External Hard Drive for DVRs 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 findings come from two security-watching quarters pointing to design flaws that affect over 12 DVR brands studied. One of those security sources, Rapid7, identified hackable video boxes using firmware provided by a China-based firm. Outside Rapid 7, a blogger, who declined to give Forbes his real name, had succeeded in disassembling a device and had run tests on it, finding that commands sent to the device via a port 9000 connection were accepted without authentication. He could use the connection to retrieve login credentials for the DVR’s web-based control panel. “A whole slew of security dvr [sic] devices are vulnerable to an unauthenticated login disclosure and unauthenticated command injection.”HD Moore of Rapid7 reported on the blogger’s findings, saying that “a researcher going by the name someLuser detailed a number of security flaws in the Ray Sharp DVR platform. These DVRs are often used for closed-circuit TV (CCTV) systems and security cameras. In addition to Ray Sharp, the exposures seem to affect rebranded DVR products,” he said, and listed over 12 such names. Fundamental to the problem in the identified DVR platform showing vulnerability is that it supports the Universal Plug and Play (UPnP) protocol. Many routers enable UPnP by default, exposing the vulnerable DVR to the Internet. The DVRs are automatically made visible to external connections using the UPnP protocol. Rapid7 ‘s Moore attributes the problem to design potentially leaving homes and businesses exposed “because of the way these things cut holes in the firewall.”Moore was able to identify some companies that seem to use the code. One of them, Zmodo, however, said it does not use faulty code and that it developed its own inhouse firmware with a substantially higher level of security, and has never been susceptible to the same intrusions as the firmware pegged as vulnerable. Other vendors may tackle the problem sooner than later too. Several vendors that had been listed reported that they were investigating the matter.Meanwhile, the blogger someLuser suggested owners of affected DVRs temporarily disable UPNP on their routers. Rapid7 released a tool to help identify devices on its website. © 2013 Phys.org
An insect (1 mm) living in a forest canopy (10 m) illustrates the effects animal-bacterial interactions across multiple scales. Bacteria (1 micrometer) residing in the animal’s gut (0.1 mm) are essential to the insect’s nutrition, and insects often make up a majority of the animal biomass in forest canopies. Credit: Margaret McFall-Ngai, et al. ©2013 PNAS (Phys.org)—Throughout her career, the famous biologist Lynn Margulis (1938-2011) argued that the world of microorganisms has a much larger impact on the entire biosphere—the world of all living things—than scientists typically recognize. Now a team of scientists from universities around the world has collected and compiled the results of hundreds of studies, most from within the past decade, on animal-bacterial interactions, and have shown that Margulis was right. The combined results suggest that the evidence supporting Margulis’ view has reached a tipping point, demanding that scientists reexamine some of the fundamental features of life through the lens of the complex, codependent relationships among bacteria and other very different life forms. The percentage of the human genome that arose at a series of stages in evolution. 37% of human genes originated in bacteria. Credit: Margaret McFall-Ngai, et al. ©2013 PNAS Explore further Journal information: Proceedings of the National Academy of Sciences After helping get animals started, bacteria also played an important role in helping them along their evolutionary path. While animal development is traditionally thought to be directed primarily by the animal’s own genome in response to environmental factors, recent research has shown that animal development may be better thought of as an orchestration among the animal, the environment, and the coevolution of numerous microbial species. One example of this coevolution may have occurred when mammals evolved endothermy, or the ability to maintain a constant temperature of approximately 40 °C (100 °F) by metabolic means. This is also the temperature at which mammals’ bacterial partners work at optimum efficiency, providing energy for the mammals and reducing their food requirement. This finding suggests that bacteria’s preferred temperature may have placed a selection pressure on the evolution of genes associated with endothermy.Bacterial signaling Evidence for a deep-rooted alliance between animals and bacteria also emerges in both groups’ genomes. Researchers estimate that about 37% of the 23,000 human genes have homologs with bacteria and Archaea, i.e., they are related to genes found in bacteria and Archaea that were derived from a common ancestor.Many of these homologous genes enable signaling between animals and bacteria, which suggests that they have been able to communicate and influence each other’s development. One example is Hadfield and his group’s discovery that bacterial signaling plays an essential role in inducing metamorphosis in some marine invertebrate larvae, where the bacteria produce cues associated with particular environmental factors. Other studies have found that bacterial signaling influences normal brain development in mammals, affects reproductive behavior in both vertebrates and invertebrates, and activates the immune system in tsetse flies. The olfactory chemicals that attract some animals (including humans) to their prospective mates are also produced by the animals’ resident bacteria. Bacterial signaling is not only essential for development, it also helps animals maintain homeostasis, keeping us healthy and happy. As research has shown, bacteria in the gut can communicate with the brain through the central nervous system. Studies have found that mice without certain bacteria have defects in brain regions that control anxiety and depression-like behavior. Bacterial signaling also plays an essential role in guarding an animal’s immune system. Disturbing these bacterial signaling pathways can lead to diseases such as diabetes, inflammatory bowel disease, and infections. Studies also suggest that many of the pathogens that cause disease in animals have “hijacked” these bacterial communication channels that originally evolved to maintain a balance between the animal and hundreds of beneficial bacterial species. Signaling also appears in the larger arena of ecosystems. For example, bacteria in flower nectar can change the chemical properties of the nectar, influencing the way pollinators interact with plants. Human infants who are born vaginally have different gut bacteria than those delivered by Caesarean section, which may have long-lasting effects. And bacteria feeding on dead animals can repel animal scavengers—organisms 10,000 times their size—by producing noxious odors that signal the scavengers to stay away.In the gutIn the earliest animals, gut bacteria played an important role in nutrition by helping animals digest their food, and may have influenced the development of other nearby organ systems, such as the respiratory and urogenital systems. Likewise, animal evolution likely drove the evolution of the bacteria, sometimes into highly specialized niches. For example, 90% of the bacterial species in termite guts are not found anywhere else. Such specialization also means that the extinction of every animal species results in the extinction of an unknown number of bacterial lineages that have evolved along with it.Scientists have also discovered that bacteria in the human gut adapts to changing diets. For example, most Americans have a gut microbiome that is optimized for digesting a high-fat, high-protein diet, while people in rural Amazonas, Venezuela, have gut microbes better suited for breaking down complex carbohydrates. Some people in Japan even have a gut bacterium that can digest seaweed. Researchers think the gut microbiome adapts in two ways: by adding or removing certain bacteria species, and by transferring the desired genes from one bacterium to another through horizontal gene transfer. Both host and bacteria benefit from this kind of symbiotic relationship, which researchers think is much more widespread than previously thought.The big pictureAltogether, the recent studies have shown that animals and bacteria have histories that are deeply intertwined, and depend on each other for their own health and well-being as well as that of their environments. Although the researchers focused exclusively on animal-bacteria interactions, they expect that similar trends of codependency and symbiosis are universal among and between other groups, such as Archaea, fungi, plants, and animals. Once considered an exception, such intermingling is now becoming recognized as the rule—just as Margulis predicted many decades ago. Due to these symbiotic relationships, the scientists here propose that the very definitions of an organism, an environment, a population, and a genome have become blurred and should be reviewed. It may be, for instance, that animals are better viewed as host-microbe ecosystems than as individuals. The project to review the current research on animal-bacterial interactions began when some scientists recognized the importance of bacteria in their own fields of study. For Michael Hadfield, Professor of Biology at the University of Hawaii at Manoa, the recognition grew over many years while studying the metamorphosis of marine animals. He found that certain bacteria influence marine larvae to settle to particular places on the sea floor, where they transform into juveniles and live out the rest of their lives. “Once we determined that specific biofilm bacteria provide an essential and unique ligand to stimulate the larvae of one globally distributed marine worm, our research naturally progressed to a study of the portion of the bacterial genome responsible for the signaling, and to other species, where we found the same genes involved,” Hadfield told Phys.org. “Coming from different perspectives on the study of animal-bacterial interactions, and recognizing many more, Margaret McFall-Ngai [Professor of Medical Microbiology and Immunology at the University of Wisconsin, Madison] and I discussed the current situation extensively and then decided to attempt to draw together a significant number of experts on various approaches to the study of bacterial-animal interactions to draft a paper such as the one you have in hand. We proposed a ‘catalysis meeting’ on the subject to the National Science Foundation’s National Evolutionary Synthesis Center (NESCent), which was funded, and the project took off.”Bacteria surround usIn many respects, it’s easy to see the prominent role that bacteria play in the world. Bacteria were one of the first life forms to appear on Earth, about 3.8 billion years ago, and they will most likely survive long after humans are gone. In the current tree of life, they occupy one of the three main branches (the other two are Archaea and Eucarya, with animals belonging to the latter). Although bacteria are extremely diverse and live nearly everywhere on Earth, from the bottom of the ocean to the inside of our intestines, they have a few things in common. They are similar in size (a few micrometers), they are usually made of either a single cell or a few cells, and their cells don’t have nuclei. Symbiotic microbes induce profound genetic changes in their hosts Citation: We are living in a bacterial world, and it’s impacting us more than previously thought (2013, February 15) retrieved 18 August 2019 from https://phys.org/news/2013-02-bacterial-world-impacting-previously-thought.html In addition, the scientists predict that the recent findings on animal-bacteria interactions will likely require biologists to significantly alter their view of the fundamental nature of the entire biosphere. Along these lines, large-scale research projects such as the Human Microbiome Project and the Earth Microbiome Project are already underway to investigate the wide range of bacteria in the individual and global systems, and to see what happens when the bacteria are disturbed. In the end, the scientists hope that the results will promote more cross-disciplinary collaboration among scientists and engineers from different fields to explore the new microbial frontier. They argue that these discoveries should revolutionize the way that biology is taught from the high school level on up, by focusing more on the relationships between bacteria, their animal partners, and all other life forms.”It is hard to summarize a single ‘most important conclusion,’ other than the admonition to biologists studying animals, from behavior to physiology and ecology to molecular biology, that no matter what process you think you are studying, you must look for and consider a major role for bacteria,” Hadfield said. “In many cases, this may require partnerships across traditional boundaries of research, meaning that zoologists must collaborate with microbiologists to advance their research, that molecular biologists must collaborate with whole-organism biologists, etc. We want badly for the message in ‘Animals in a bacterial world,’ to be a call for the necessary disappearance of the old boundaries between life science departments (e.g., Depts of Zoology, Botany, Microbiology, etc.) in universities, and societies (e.g., the American Society for Microbiology, etc.). We also want the message disseminated in college and university classes from introductory biology to advanced courses in the various topic areas of our paper.”The results will profoundly change the way that the scientists of this collaboration continue with their own areas of research, Hadfield said.”Each of the authors of our paper conducts basic research in one or more areas of animal-bacterial interactions discussed in the paper, and each will continue to focus on her/his own speciality, I’m sure,” he said. “However, I’m also certain that the interactions developed during the composition and writing of the paper (starting with our NESCent meeting in October 2011, when most of us met for the first time) will impact our own research and cause us to establish new collaborations with other laboratories. That has already occurred for me; I have a new collaboration with Dianne Newman’s group at CalTech, an outstanding group of bacteriologists who are helping us do a much more in-depth investigation of the bacterial gene-products responsible for larval development.” Although scientists have known for many years that animals serve as a host for bacteria, which live especially in the gut/intestines, in the mouth, and on the skin, recent research has uncovered just how numerous these microbes are. Studies have shown that humans have about 10 times more bacterial cells in our bodies than we have human cells. (However, the total bacteria weigh less than half a pound because bacterial cells are much smaller than human cells.) While some of these bacteria simply live side-by-side with animals, not interacting much, some of them interact a lot. We often associate bacteria with disease-causing “germs” or pathogens, and bacteria are responsible for many diseases, such as tuberculosis, bubonic plague, and MRSA infections. But bacteria do many good things, too, and the recent research underlines the fact that animal life would not be the same without them.”The true number of bacterial species in the world is staggeringly huge, including bacteria now found circling the Earth in the most upper layers of our atmosphere and in the rocks deep below the sea floor,” Hadfield said. “Then add all of those from all of the possible environments you can think of, from cesspools to hot springs, and all over on and in virtually every living organism. Therefore, the proportion of all bacterial species that is pathogenic to plants and animals is surely small. I suspect that the proportion that is beneficial/necessary to plants and animals is likewise small relative to the total number of bacteria present in the universe, and surely most bacteria, in this perspective, are ‘neutral.’ However, I am also convinced that the number of beneficial microbes, even very necessary microbes, is much, much greater than the number of pathogens.”Animal origins and coevolutionFrom our humble beginnings, bacteria may have played an important role by assisting in the origins of multicellular organisms (about 1-2 billion years ago) and in the origins of animals (about 700 million years ago). Researchers have recently discovered that one of the closest living relatives of multicellular animals, a single-celled choanoflagellate, responds to signals from one of its prey bacterium. These signals cause dividing choanoflagellate cells to retain connections, leading to the formation of well-coordinated colonies that may have become multicellular organisms. However, such questions of origin have been subjects of intense debate, and scientists have many hypotheses about how these life forms emerged. A bacterial role in these processes does not exclude other perspectives but adds an additional consideration. Bacteria in an animal’s microbiota, such as those in the gut, in the mouth, and on the skin, communicate among themselves and exchange signals with the animal’s organ systems. Some of the chemical signals are noted in this illustration. Credit: Margaret McFall-Ngai, et al. ©2013 PNAS More information: Margaret McFall-Ngai, et al. “Animals in a bacterial world, a new imperative for the life sciences.” PNAS Early Edition. DOI: 10.1073/pnas.1218525110 Copyright 2013 Phys.org All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of Phys.org. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Citation: Astronomers discover the longest galaxy-scale stripping process ever observed (2015, November 7) retrieved 18 August 2019 from https://phys.org/news/2015-11-astronomers-longest-galaxy-scale.html Journal information: Astronomy & Astrophysics (Phys.org)—Astronomers from the University of Bonn in Germany, have discovered what appears to be the longest X-ray tail associated with a stripping process from a galaxy on a large scale. This galaxy with the enormous X-ray tail is a member of a galaxy cluster known as Zwicky 8338. The researchers detailed their findings in a paper published on Nov. 2 in the Astronomy & Astrophysics journal. © 2015 Phys.org More information: Astronomy & Astrophysics, www.aanda.org/articles/aa/pdf/ … 15/11/aa27317-15.pdf Galaxy Cluster Abell 3627: Two Tails to Tell Gerrit Schellenberger and Thomas Reiprich observed Zwicky 8338 using NASA’s Chandra X-ray observatory. They found out that one of the galaxies grouped in this cluster showcases a very long X-ray tail, which is approximately 248,000 light years in length. What is surprising is that the galaxy must have lost all of its X-ray emitting gas very recently.”It is likely the longest X-ray tail associated with a stripping process from a galaxy with the largest separation from the host galaxy ever detected,” they wrote in the paper.The observed galaxy, designated CGCG254-021, is located slightly more than one million light years from the center of Zwicky 8338. The researchers discovered that it resembles a comet, having distinctive features like a ‘head’ and a ‘tail’. The head, as it is described in the paper, is brighter than the galaxy’s tail, which is simply an elongated structure of diffuse emission.The scientists indicate that in the region outside the main tail, the temperature seems to be significantly higher than any part of the tail but still much lower than in the surrounding cluster region. They found out that the head is cooler than the tail, possibly due to a dense cool core.The researchers also tried to determine the chemical composition of this comet-like galaxy.”Despite the large uncertainties, there might be indications that the tail has a much lower abundance of heavy elements than the head of the comet, which is again consistent with the head being the remnant of a cool core,” the paper reads.The curious case of CGCG254-021 could bring important results in the field of cosmology and could improve our understanding about galaxy clusters. The crucial role in the stripping process as seen in this comet-shaped galaxy is played by the intracluster medium (ICM). It is a very hot plasma located at the center of a galaxy cluster. This plasma is enriched with heavy elements, such as iron. The researchers believe that the interaction of the ICM with subclusters or galaxy groups can produce bright X-rays and long tails such as the elongated tail described in this study.”Halo gas and the cold inter stellar medium (ISM) from the galaxy can then be stripped and interact with the ICM. Part of the gas from the galaxy is then used for new stars, either in the galactic halo or outside the galaxy in the ICM,” the researchers note.They point out that the amount of gas that apparently has been stripped from the galaxy is very high; the galaxy could lose almost all of its gas to the ICM. If the researchers are able to confirm this through the analysis of a longer observation, there would be a chance to study in detail the properties of this interaction for such a luminous and massive object. They conclude that a deeper X-ray observation is needed to characterize more detailed properties as well as a definite scenario for the interaction history. Adaptively smoothed X-ray image of galaxy cluster Zwicky 8338. Credit: Gerrit Schellenberger, Thomas Reiprich. 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 Permian-Triassic mass extinction lasted for approximately 60,000 years, and was undoubtedly a tough time for the creatures that lived back then—prior research has suggested that there was an unusually large amount of volcanic activity and also possibly multiple large asteroid impacts, which together caused the planet to warm, and also resulted in an increase in ocean acidification—the conditions were so harsh that many species on land and in the sea went extinct. But, Stanley argues, it was not bad enough to wipe out most marine life entirely, as some have suggested. He points out that most extinction estimates for the period fail to include background extinctions, which are extinctions that occur between mass extinctions—they tend to occur as a species runs up against a situation it cannot overcome, such as a new predator, a change in water supply, etc.Stanley studied the numbers of species that went extinct between known mass extinction events and found a correlation with their numbers and the length of time that passed—the longer the period, the more background extinctions. He then applied the same logic to the time span prior to the Permian-Triassic mass extinction and found that many of the species believed to have gone extinct during the great dying would have actually died out, statistically speaking, before it occurred or would have died during the event anyway. Subtracting those species from the numbers believed to have disappeared brought the percentage down to 81 percent—which Stanley notes is still substantial; it was just not as calamitous as thought. He further suggests that 90 orders and 220 families of marine life survived the mass extinction event and that the factors leading to the extinctions were much more difficult to overcome for some orders and classes than others, which meant that there were disproportionate numbers of losses. Some likely were never close to extinction, he suggests. Lystrosaurus was by far the most abundant early Triassic land vertebrate. Credit: Nobu Tamura/Wikipedia/CC BY 3.0 © 2016 Phys.org Arctic gives clues on worst mass extinction of life (Phys.org)—Paleontologist and evolutionary biologist Steven Stanley of the University of Hawaii has challenged the notion that the Permian-Triassic mass extinction event 252 million years ago killed off up to 96 percent of all marine life. Instead, he claims in his paper published in Proceedings of the National Academy of Sciences, that background extinctions should account for some of that loss, and because of that, the actual extinction rate for marine life was probably closer to 81 percent. More information: Steven M. Stanley. Estimates of the magnitudes of major marine mass extinctions in earth history, Proceedings of the National Academy of Sciences (2016). DOI: 10.1073/pnas.1613094113AbstractProcedures introduced here make it possible, first, to show that background (piecemeal) extinction is recorded throughout geologic stages and substages (not all extinction has occurred suddenly at the ends of such intervals); second, to separate out background extinction from mass extinction for a major crisis in earth history; and third, to correct for clustering of extinctions when using the rarefaction method to estimate the percentage of species lost in a mass extinction. Also presented here is a method for estimating the magnitude of the Signor–Lipps effect, which is the incorrect assignment of extinctions that occurred during a crisis to an interval preceding the crisis because of the incompleteness of the fossil record. Estimates for the magnitudes of mass extinctions presented here are in most cases lower than those previously published. They indicate that only ∼81% of marine species died out in the great terminal Permian crisis, whereas levels of 90–96% have frequently been quoted in the literature. Calculations of the latter numbers were incorrectly based on combined data for the Middle and Late Permian mass extinctions. About 90 orders and more than 220 families of marine animals survived the terminal Permian crisis, and they embodied an enormous amount of morphological, physiological, and ecological diversity. Life did not nearly disappear at the end of the Permian, as has often been claimed. Journal information: Proceedings of the National Academy of Sciences This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Paleontologist suggests ‘great dying’ 252 million years ago wasn’t as bad as thought (2016, October 4) retrieved 18 August 2019 from https://phys.org/news/2016-10-paleontologist-great-dying-million-years.html Explore further
Swift UVOT U (top panel), UVM2 (middle panel) and 0.3–10 keV XRT (bottom panel) light curves of Ark 120 from Sept. 4, 2014 to Mar. 9, 2015. The UV fluxes are corrected for Galactic absorption and expressed in units of mJy. On top of the X-ray time series we superimposed the UVM2 light curve normalized to have the same mean as the X-ray light curve. The dot-dashed and dashed lines on the X-ray light curve represent the threshold values used for the flux-selected spectral analysis. Credit: Gliozzi et al., 2016. 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. © 2016 Phys.org (Phys.org)—Astronomers using NASA’s Swift space observatory, have conducted a long-term monitoring campaign of a prototypical active galaxy, designated Arakelian 120 (Ark 120 for short). These observations reveal crucial information about the galaxy’s variability, giving a hint about its true nature. The findings are presented in a paper published Oct. 13 on the arXiv pre-print server. Citation: Prototypical active galaxy Arakelian 120 observed by Swift (2016, October 18) retrieved 18 August 2019 from https://phys.org/news/2016-10-prototypical-galaxy-arakelian-swift.html Ark 120 was classified as a luminous “bare” Seyfert 1 galaxy as its nucleus is free from significant reddening or contamination from the host galaxy. As a rare example of a bright Seyfert 1 galaxy that is not significantly affected by any kind of complex absorption, Ark 120 was a target of numerous past observations. Due to the fact that this active galaxy stands out among bright Seyfert galaxies and is a highly variable source over the entire spectrum, it makes it a perfect target for monitoring with Swift.A team of astronomers, led by Mario Gliozzi of the George Mason University in Fairfax, Virginia, carried out a series of Swift observations between September 2014 and March 2015 to investigate Ark 120. Such multi-wavelength monitoring observations that track variable behavior are much promising for scientists investigating active galactic nuclei (AGN) residing at the centers of active galaxies.Ark 120 has a central black hole with a mass of about 150 million solar masses. According to the paper, the observations confirm the presence of significant large-amplitude variability for such a large black hole mass in all bands probed by Swift’s Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT). The results show that the X-ray band is by far the most variable component, and indicate that the temporal variability of Ark 120 is associated with spectral changes of the X-rays and also of the broadband spectral energy distribution.”The spectral analysis based on model fitting of flux-selected spectra confirms the existence of spectral variability during the Swift campaign of Ark 120 revealed by the model independent spectral variability analysis, with steeper spectra observed when the source has higher count rate,” the researchers wrote in the paper.The team found that the strong variability in X-ray and UV bands occurs on all timescales investigated by the Swift campaign. Additionally, the continuous temporal variability of Ark 120 appears to be associated with persistent spectral variability based on various model-independent analyses. Moreover, the spectral analysis allowed the team to conclude that the steeper-when-brighter behavior is caused by the steepening of the photon index.In general, the Swift observations provided a wealth of data that helped the scientists to reveal the nature of Ark 120. The study confirms that it behaves as a typical Seyfert galaxy with persistent X-ray and also UV flux variability associated with spectral variability, where the spectrum softens as the source brightens.”This spectral behavior too is common to the vast majority of Seyfert galaxies. However, the ‘bare’ nature of Ark 120 ensures that the spectral variability is caused by intrinsic changes in the primary emission, rather than being associated with variations of the absorber surrounding the source,” the paper reads. More information: Long-term monitoring of Ark 120 with Swift, arXiv:1610.04104 [astro-ph.HE] arxiv.org/abs/1610.04104AbstractWe report the results of a six-month Swift monitoring campaign of Ark120, a prototypical bare Seyfert1 galaxy. The lack of intrinsic absorption combined with the nearly contemporaneous coverage of the UV and X-ray bands makes it possible to investigate the link between the accretion disk and the Comptonization corona. Our observations confirm the presence of substantial temporal variability, with the X-rays characterized by large-amplitude flux changes on timescales of few days, while the variations in the UV bands are smoother on timescales of several weeks. The source also shows spectral variability with the X-ray spectrum steepening when the source is brighter. We do not detect any correlation between the UV flux and the X-ray spectral slope. A cross correlation analysis suggests positive delays between X-rays and the UV emission, favoring a scenario of disk reprocessing. Although the strength of the correlation is moderate with a delay not well constrained (7.5+-7 days), it is nevertheless indicative of a large disk reprocessing region, with a separation between the X-ray and the UV emitting regions of the order of 1000 rG. The Ark120 correlation results are in agreement with those obtained in similar monitoring studies. When combined together, the observations can be well described by a linear relation between the X-ray/UV delay and the black hole mass. Within the context of the simplest scenario where these delays correspond to light-travel times, the implied distance between the X-ray source and the UV disk reprocessing region is of the order of many hundreds of gravitational radii. Astronomers observe a supergiant fast X-ray transient prototype Explore further
This research examines pain ratings during the deliberate infliction of physical injury to one’s own body without intent of suicide (i.e., nonsuicidal self-injury, or NSSI). Participants (15- to 21-year-olds who engaged in NSSI) received prompts on their phones five times a day for 2 weeks asking them to rate the extent to which they were feeling negative emotions (e.g., sadness, anger, being overwhelmed) and to assess whether they had thoughts of self-injury and whether they had engaged in NSSI since the last assessment. When participants reported having engaged in NSSI, they were asked to report their experience of physical pain before, during, and after the NSSI episode. Results suggest that most participants felt pain during most NSSI episodes, and some felt that pain diminished after the NSSI completion, even though it was still higher than before NSSI. However, many participants reported not feeling pain during NSSI. Participants who experienced less pain during NSSI and more negative emotions before the NSSI reported more NSSI behaviors. But participants with higher fluctuations in negative emotions and who reported more pain during NSSI also self-injured more. These results suggest a complex pattern of the relationship between pain, NSSI, and negative emotions. These relationships vary between people and episodes, and understanding them better may enhance current treatments for NSSI. The Phenomenology and Correlates of Flashbacks in Individuals With Posttraumatic Stress SymptomsAnne L. Malaktaris and Steven Jay Lynn The Dynamics of Pain During Nonsuicidal Self-Injury Edward A. Selby, Amy Kranzler, Janne Lindqvist, Kara B. Fehling, Julia Brillante, Fengpeng Yuan, Xianyi Gao, and Alec L. Miller Read about research published in Clinical Psychological Science: People acquire more calories from eating hot food than from eating the same food cold, since they expend more calories digesting cold food. Therefore, the authors propose, the widespread use of microwave ovens to reheat food might have played a small role in the current increases in obesity rates. Using data from the British Cohort Study, which tracked individuals born in Great Britain from their birth in 1970 until 2012, the authors analyzed individuals’ body mass indexes (BMI; people with BMI of 30 or more are considered obese), dietary habits, physical-activity frequency, and household, including the existence of a microwave. The researchers found that individuals whose households had a microwave were more likely to have a higher BMI, regardless of their dietary preferences and physical activity. The researchers also looked at U.S. obesity rates from 1960 to 2014 and estimates of the proportion of American households with microwaves during the same period. They found that as the rate of microwave ownership increased, obesity rates also increased. Given the complexity of the obesity epidemic, which has implications for mental health and pathology, identifying even a potentially small contributor, such as increased microwave use, may increase understanding of the phenomenon. Understanding the mechanisms that generate false memories is important in mental health and legal contexts. Recently, Otgaar and colleagues (2017) proposed that associative activation is a viable mechanism for generating false memories. According to the associative activation framework, activation of one concept activates other associated concepts, the automatic spread of activation reaches highly associated concepts that were not presented, and false memories are formed. However, Tryon (2018) argued that Otgaar et al.’s description of associative activation did not meet the criteria of causation and explanation to qualify as a mechanism. In this commentary, Otgaar and colleagues disagree with Tryon and present several studies providing evidence for associative activation as a likely cause of false memories. For example, the higher the semantic association between presented words and an associated nonpresented word, the higher the probability of falsely remembering the nonpresented word. Otgaar and colleagues agree with Tryon that it is vital to establish whether something can be called a mechanism but believe there is evidence for associative activation to be considered a mechanism for the creation of false memories. Recognizing at least one mechanism of false memories may elucidate how false memories occur in legal cases and therapy. A Potential Role of the Widespread Use of Microwave Ovens in the Obesity EpidemicSatoshi Kanazawa and Marie-Therese von Buttlar Individuals with posttraumatic stress disorder (PTSD) often experience flashbacks to traumatic memories. But what are these flashbacks like? Participants with PTSS (i.e., PTSD or subthreshold PTSD symptoms) reported the frequency, severity, and sensory properties of their flashbacks. These data were then compared with ratings of imagined flashbacks provided by participants with PTSS who did not experience flashbacks, participants without PTSS but with trauma exposure, and participants without trauma exposure. Only participants without PTSS underestimated the vividness, emotional intensity, distress, and functional impact associated with flashbacks. Moreover, flashbacks of individuals with PTSS were not fragmented but rather coherent. Other psychological characteristics were also assessed, and participants with PTSS with and without flashbacks reported greater symptom severity, including more sleep complaints and dissociative symptoms. Participants with PTSS also reported greater psychological inflexibility, lower mindfulness, and higher experiential avoidance (i.e., avoiding thoughts, memories, and experiences). These results suggest a meaningful connection between PTSD symptoms and mindfulness and highlight the possible utility of clinical approaches that enhance mindfulness skills and psychological flexibility to treat PTSD. Associative Activation as a Mechanism Underlying False Memory Formation Henry Otgaar, Mark L. Howe, Peter Muris, and Harald Merckelbach
Is there any one place that offers the sight of the rich and diverse flora and fauna of India, all at once? Well, all the wild, endangered and beautiful species are on board a special train to meet the young and curious in Delhi. To revive an innovative exhibition on rail that started last year, Science Express Biodiversity (SEBS) is being relaunched in its second phase on Tuesday, 9 April.It is a 16 coach train with eight coaches dedicated to interactive exhibits carrying shorts films, videos, kiosks and back lit panels to showcase the biodiversity of India. The highlight is the Joy Science Lab which is an open platform for students to perform guided experiments and revel in the myriad of activities thrown open to them. Also Read – ‘Playing Jojo was emotionally exhausting’A group of dignitaries are expected to grace the flag off ceremony from Safdarjung on 9 April; the expected list includes Minister of Environment and Forests, Jayanthi Natrajan and Chief Minister of Delhi, Sheila Dikshit.This train will be stationed at the Pragati Maidan railway station from 10 to 13 April for a free of cost exhibition of the biodiversity of India. It has on board a team of 40 young and qualified science intellectuals to facilitate the visitors throughout the journey.
Kolkata: A private tutor from Dum Dum has been arrested for allegedly beating up a class V student from a English medium school in the same area.The accused has been identified as Subhra Poddar. According to police, Poddar had allegedly tortured a student who used to visit her place to take private tuition. The family members of the victim told the police apart from beating him up, the accused also used to threaten the student with dire consequences if he discloses the incident to his family. Also Read – Heavy rain hits traffic, flightsThe family members of the victim boy also alleged that police were not taking any action despite a complaint lodged with the local police station three days ago. The family members of the student accompanied by some locals staged a sit-in demonstration outside the Dum Dum police station on Sunday morning. Following the agitation, police swung into action and arrested the accused teacher from her residence in Bediapara area.The family members of the student said the victim went to her place to take private tuition on April 26. It was alleged that the boy forgot to take a notebook where he was supposed to do some homework. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe accused teacher asked the student to produce his notebook. As he failed to do so, the teacher became infuriated and beat him up with a stick. The victim suffered injuries on various parts of his body. The accused also threatened the victim to not tell his family members about the incident. The victim returned home at around 9.30 pm on the same day and was in a traumatized state. The victim broke into tears when his parents wanted to know about the incident. After he complained about the pain in his body, the victim was taken to a local doctor.