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Zombie Bees :|
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http://news.yahoo.com/mystery-pompei...130608439.html
The mystery of Pompeii's trashy tombs explained. |
Scientists Look to European Bats for Answers on White Nose Fungus in U.S.
By Rachel Bogart According to the Associated Press, Craig Willis, a biologist from the University of Winnipeg, is looking for a solution to control white nose fungus, a disease that is killing bats in several U.S. states, by studying a similar fungus in European bats. Numerous bats in Europe have survived the fungus and scientists believe white nose fungus spread to the U.S. from Europe. Willis' research has focused around finding this link and proving that the fungus is an invasive species. This would ultimately lead to scientists researching why the fungus has been so fatal in the U.S. and help scientists manage the disease. Here are some facts about white nose fungus and how its impacted bats in the country: * The U.S. Fish and Wildlife Service reported that white nose fungus, also known as white nose syndrome, was first found in February 2006 in a cave about 40 miles of Albany, N.Y. * As of October 2010, white nose syndrome has been confirmed in New York, Maine, New Hampshire, Vermont, Connecticut, West Virginia, Ohio, Indiana, Virginia, Kentucky, Tennessee, North Carolina, Massachusetts, and Maryland, as well as several areas in Canada. * Government agencies have continued to close off caves to the public in hopes of quarantining the disease while scientists try to find out more about the spread of the problem, according to Wired. * By declaring the fungus an invasive species, wildlife agencies would have increased access to funds in order to fight it. * Since March of 2008, scientists estimate that more than one million bats have died from the disease, with a majority being little brown bats, according to the USGS National Wildlife Health Center. * Infected bats can be identified by having white fungal growth on their muzzles and or wing tissue, though infected bats don't always have these symptoms, in addition to displaying abnormal behavior. * An article from ABC News noted that the abnormal behavior associated with white nose syndrome is what kills the bats, specifically causing them to end their hibernation early and starving to death in winter. * In some areas hit by the disease, the mortality rate of infected bats is as high as 90 percent. * Bats are especially susceptible to white nose syndrome during hibernation since bats congregate in large numbers in caves, reported the New York Department of Environmental Conservation. * Indiana bats are likely the most vulnerable it's a state and federally endangered species with 50 percent of the bats hibernating in a former mine that has been confirmed as having white nose syndrome. [IMG]http://www.geog.ucsb.edu/img/news/20...avesClosed.jpg[/IMG] |
Wonder if its like when "civilized" nations went to new countries and killed off the indiginous population with TB, small pox etc.
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http://news.yahoo.com/complete-civil...004714070.html
Hunley I just want to know how 7 people got into that thing... |
http://news.yahoo.com/researchers-tr...160144542.html
I would rather the remains go to the tribes than remain with researchers. |
Carefully.... ;+)
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http://www.physorg.com/news/2011-04-...dimension.html
A bit over my head. Maybe y'all can understand it. |
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Absolutely gorgeous...
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Latest ScienceCast from NASA exploring the snow drought (despite evidence to the contrary this weekend) and describing the effects of La Nina and the Arctic Oscillation:
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"Fossils of ancient sea creature discovered
Toronto researchers make 500-million-year-old find in Tulip Beds in Canadian Rockies" source: http://www.cbc.ca/news/technology/st...-creature.html |
"Dirty dancing: dung beetles get down to walk the line
The meticulous insects pirouette atop their dung balls to get their bearings and correct navigational errors." source:http://www.nature.com/news/dirty-dan...he-line-1.9868 |
Aye-aye is an odd little creature :)
"Aye-aye lemur 'heats up' its special foraging finger
By Ella Davies Reporter, BBC Nature" source: http://www.bbc.co.uk/nature/16577537 |
How The Biggest Solar Storm Since 2005 Is Going to Affect You
By Jesus Diaz Jan 23, 2012 8:42 PM http://cdni.wired.co.uk/620x258/s_v/...rm_620x258.jpg There's a solar Coronal Mass Ejection travelling towards us at 1,400 miles per second, the largest solar storm since 2005. It will hit Earth around 9am Eastern Time, causing fluctuations on the power grid and disruptions to the Global Positioning System. Don't worry, you won't die. But there's something else, a strong proton storm—ranking S3 on a 5-level scale—which is in full rage now and gradually increasing. While CMEs are normal—about 2,000 every 11-year solar cycle—proton storms are very rare. Only a couple of dozen happen per solar cycle. And this one can be dangerous. The storm has already affected aircraft traffic and may affect satellites' computers. On a telephone interview, NOAA's Space Weather Prediction Center physicist Doug Biesecker told me that, fortunately, there are measures to avoid most dangers. "Many airliners have been avoiding the North Pole routes because they are more exposed to the proton storm, which disrupts High Frequency radio communications," he said on a telephone interview. HF datalinks are crucial to modern airflight, as they keep aircraft connected to Air Traffic Control. Due to the structure of the magnetic field that surrounds Earth, the polar cusps have very little protection against outbursts of solar radiation, so any airplane crossing that area could be exposed to this mayhem. We're experiencing technical difficulties He also said that satellites may be affected, causing reboots on onboard computers as well as noise in imaging systems and interferences in telemetry caused by something called single event offsets. These events may change the values of the telemetry data. Since we are aware of these interferences in advance, engineers on ground bases can take them into account and make corrections before firing any commands that may jeopardize the life of the spacecraft. The only real unpredictable danger is a total hardware failure, with a proton hitting an electronic component and killing it. But according to Biesecker, this "is a very remote possibility." Global positioning systems are also affected—and will be even more affected tomorrow. Regular humans will not notice this. You will be able to keep using your GPS normally, but people using high precision GPS equipments—like oil drilling, military, engineering and mining operations—will definitely notice the problems. According to Karen Fox at NASA Goddard Space Center, "NASA alerted operators of their satellites that the CME was coming, so those operators can take whatever shielding precautions they can." The biological danger NOAA's scale says that an S3 proton storm may pose danger to passengers in high-flying aircraft at high latitudes, which is why some airplanes below the 65th parallel north are now actually flying at lower altitudes to avoid any kind of radiation nastiness. They also recommend for astronauts to stay home and avoid space walks but—according to Biesecker—this type of storm is "far below the level needed for the ISS to take any extraordinary protection measures." If it's ok for them, you can be sure it's perfectly fine for you and me down here on good old planet Earth. What will happen when the CME hits tomorrow morning? When the Coronal Mass Ejection arrives to Earth at 1,400 miles per second, we will have a geomagnetic storm and a radio blackout. This, apart from the possibility of awesome auroras at latitudes as low as New York, means several things. How The Biggest Solar Storm Since 2005 Is Going to Affect YouFirst, the radio blackout will be level R2, which is moderate. According to the NOAA scale, it will cause "limited blackout of HF radio communication on the sunlit side and loss of radio contact for tens of minutes," as well as "degradation of low-frequency navigation signals for tens of minutes." Nothing that you should worry about. The geomagnetic storm will only be "strong G2 with possibilities of G3," according to Bisecker. In the best case scenario, only power lines will be affected. You will not notice it because any power fluctuations will be handled by companies at the grid level. If the storm is long enough, however, it may damage power grid transformers. Other than all this, and unless something extraordinary happens, you shouldn't worry about the world ending tomorrow. It won't. But keep your eyes open for auroras happening near you. Those living up north in particular will have a great show today and tomorrow. |
Snowy owls soar south from Arctic in rare mass migration
By Laura Zuckerman | Reuters – 5 hrs ago http://l.yimg.com/bt/api/res/1.2/d_f...-MIGRATION.JPG A snowy white owl takes flight in this undated handout photo courtesy of U.S. Fish and Wildlife Service SALMON, Idaho (Reuters) - Bird enthusiasts are reporting rising numbers of snowy owls from the Arctic winging into the lower 48 states this winter in a mass southern migration that a leading owl researcher called "unbelievable." Thousands of the snow-white birds, which stand 2 feet tall with 5-foot wingspans, have been spotted from coast to coast, feeding in farmlands in Idaho, roosting on rooftops in Montana, gliding over golf courses in Missouri and soaring over shorelines in Massachusetts. A certain number of the iconic owls fly south from their Arctic breeding grounds each winter but rarely do so many venture so far away even amid large-scale, periodic southern migrations known as irruptions. "What we're seeing now -- it's unbelievable," said Denver Holt, head of the Owl Research Institute in Montana. "This is the most significant wildlife event in decades," added Holt, who has studied snowy owls in their Arctic tundra ecosystem for two decades. Holt and other owl experts say the phenomenon is likely linked to lemmings, a rodent that accounts for 90 percent of the diet of snowy owls during breeding months that stretch from May into September. The largely nocturnal birds also prey on a host of other animals, from voles to geese. An especially plentiful supply of lemmings last season likely led to a population boom among owls that resulted in each breeding pair hatching as many as seven offspring. That compares to a typical clutch size of no more than two, Holt said. Greater competition this year for food in the Far North by the booming bird population may have then driven mostly younger, male owls much farther south than normal. Research on the animals is scarce because of the remoteness and extreme conditions of the terrain the owls occupy, including northern Russia and Scandinavia, he said. The surge in snowy owl sightings has brought birders flocking from Texas, Arizona and Utah to the Northern Rockies and Pacific Northwest, pouring tourist dollars into local economies and crowding parks and wildlife areas. The irruption has triggered widespread public fascination that appears to span ages and interests. "For the last couple months, every other visitor asks if we've seen a snowy owl today," said Frances Tanaka, a volunteer for the Nisqually National Wildlife Refuge northeast of Olympia, Washington. But accounts of emaciated owls at some sites -- including a food-starved bird that dropped dead in a farmer's field in Wisconsin -- suggest the migration has a darker side. And Holt said an owl that landed at an airport in Hawaii in November was shot and killed to avoid collisions with planes. He said snowy owl populations are believed to be in an overall decline, possibly because a changing climate has lessened the abundance of vegetation like grasses that lemmings rely on. This winter's snowy owl outbreak, with multiple sightings as far south as Oklahoma, remains largely a mystery of nature. "There's a lot of speculation. As far as hard evidence, we really don't know," Holt said. |
Pythons linked to Florida Everglades mammal decline
Non-native Burmese pythons are the likely cause of a staggering mammal decline in Florida's Everglades.
http://news.bbcimg.co.uk/media/image..._s_river-1.jpg In PNAS journal, they report that observations of some mammal species have declined by more than 99%. A team studied road surveys of mammals in the Everglades National Park before and after pythons became common. Researchers found a strong link between the spread of pythons and drops in recorded sightings of racoons, rabbits, bobcats and other species. “They are a new top predator in Everglades National Park - one that shouldn't be there.” The national park covers the southern 25% of the original Everglades - a region of subtropical wetlands that has been drained over the last century to reclaim it for human use. The origins of Burmese pythons in south Florida are unknown, but many were imported into the US through the pet trade. As the pythons have made it from captivity into the wild, the absence of natural predators has allowed populations to balloon. Intermittent sightings were recorded for 20 years before the snakes were recognised as being established across the Everglades in 2000. The pythons are now established across thousands of sq km in southern Florida. Although there are no accurate figures for how many there are, the numbers removed from the Everglades reached nearly 400 in 2009 and this has been increasing year-on-year (apart from a slight drop in 2010 due to a cold spell). "Any snake population - you are only seeing a small fraction of the numbers that are actually out there," said Prof Michael Dorcas, one of the study's authors, from Davidson College in North Carolina. He told BBC News: "They are a new top predator in Everglades National Park - one that shouldn't be there." "We have documented pythons eating alligators, we have also documented alligators eating pythons. It depends on who is biggest during the encounter." Earlier this month, US Interior Secretary Ken Salazar announced that the US was poised to approve a ban on importing Burmese pythons. But some observers remarked that the move was about 30 years too late. Prof Dorcas and his colleagues looked at data on mammals found during roadkill surveys from 1993-1999, and on live and dead mammals encountered during nighttime road surveys from 1996-1997. They then compared these results with similar data collected between 2003 and 2011, after the pythons were recognised as being established. http://news.bbcimg.co.uk/media/image...5_58198801.jpg They found that observations of raccoons and opossums had dropped by about 99%. There had been a 94.1% fall in observations of white-tailed deer and an 87.5% decrease in sightings of bobcats. No rabbits or foxes were seen during the more recent survey; rabbits were among the most common mammals in the roadkill survey between 1993 and 1999. Getting ambushed? The majority of these species have been documented in the diet of pythons found in the Everglades National Park. Indeed, raccoons and oppossums often forage at the water's edge, where they are vulnerable to ambush by pythons. Observations of rodents, coyotes and Florida panthers had increased slightly, but the overall number of sightings remained low. http://news.bbcimg.co.uk/media/image...2_58178062.jpg The researchers also found that the declines in mammals coincided geographically with the spread of Burmese pythons. Mammal species are more common in areas where pythons have only been recently introduced, and are most abundant outside the snakes' current range. Bill Nelson, with 17-foot python skin US Senate Bill Nelson holds up the 5m-long skin of a Burmese python at a hearing on Capitol Hill in July 2009 Prof Dorcas said more research was needed to assess the impact of such large declines. But he added: "It's not unreasonable to assume that any time we have major declines in mammals like this it's going to have overall impacts on the ecosystem. Exactly what those are going to be, we don't know. But it's possible they could be fairly profound." The ban on importing Burmese pythons has come after five years of debate and lobbying in Washington DC. Florida's Democrat Senator Bill Nelson was among those who campaigned for a ban, unravelling the skin of a 5m-long Everglades python at a 2009 Senate hearing to make his point. But reptile breeders and collectors had disputed that the tropical snakes posed much risk beyond south Florida and argued that any ban would harm a multi-million dollar industry. Although the ban will not reverse the situation in southern Florida, where the reptiles are already established, Prof Dorcas said it could help prevent their spread to other suitable habitats in the US, such as southern Louisiana and south Texas. Paul.Rincon-INTERNET@bbc.co.uk http://www.bbc.co.uk/news/science-environment-16791094 |
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They brought him back to the safari and fed him whole chickens |
I usually watch the NASA channel or go to the web site they have, Its more updated than any other places!
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Thank you Corkey!
That link, led me to read this story-->Canoeing legend Don Starkell, famous for journey to Amazon, dies at 79
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Alien Planet 'Super-Earth' Called Best Candidate To Support Life
By: Denise Chow http://i.telegraph.co.uk/multimedia/...e_2127323b.jpg Published: 02/02/2012 10:16 AM EST on SPACE.com A potentially habitable alien planet — one that scientists say is the best candidate yet to harbor water, and possibly even life, on its surface — has been found around a nearby star. The planet is located in the habitable zone of its host star, which is a narrow circumstellar region where temperatures are neither too hot nor too cold for liquid water to exist on the planet's surface. "It's the Holy Grail of exoplanet research to find a planet around a star orbiting at the right distance so it's not too close where it would lose all its water and boil away, and not too far where it would all freeze," Steven Vogt, an astronomer at the University of California, Santa Cruz, told SPACE.com. "It's right smack in the habitable zone — there's no question or discussion about it. It's not on the edge, it's right in there." Vogt is one of the authors of the new study, which was led by Guillem Anglada-Escudé and Paul Butler of the Carnegie Institution for Science, a private, nonprofit research organization based in Washington, D.C. "This planet is the new best candidate to support liquid water and, perhaps, life as we know it," Anglada-Escudé said in a statement. An alien super-Earth The researchers estimate that the planet, called GJ 667Cc, is at least 4.5 times as massive as Earth, which makes it a so-called super-Earth. It takes roughly 28 days to make one orbital lap around its parent star, which is located a mere 22 light-years away from Earth, in the constellation Scorpius (the Scorpion). "This is basically our next-door neighbor," Vogt said. "It's very nearby. There are only about 100 stars closer to us than this one." Interestingly enough, the host star, GJ 667C, is a member of a triple-star system. GJ 667C is an M-class dwarf star that is about a third of the mass of the sun, and while it is faint, it can be seen by ground-based telescopes, Vogt said. [Gallery: The Strangest Alien Planets] "The planet is around one star in a triple-star system," Vogt explained. "The other stars are pretty far away, but they would look pretty nice in the sky." The discovery of a planet around GJ 667C came as a surprise to the astronomers, because the entire star system has a different chemical makeup than our sun. The system has much lower abundances of heavy elements (elements heavier than hydrogen and helium), such as iron, carbon and silicon. "It's pretty deficient in metals," Vogt said. "These are the materials out of which planets form — the grains of stuff that coalesce to eventually make up planets — so we shouldn't have really expected this star to be a likely case for harboring planets." The fortuitous discovery could mean that potentially habitable alien worlds could exist in a greater variety of environments than was previously thought possible, the researchers said. "Statistics tell us we shouldn't have found something this quickly this soon unless there's a lot of them out there," Vogt said. "This tells us there must be an awful lot of these planets out there. It was almost too easy to find, and it happened too quickly." The detailed findings of the study will be published in the Astrophysical Journal Letters. An intriguing star system Another super-Earth that orbits much closer to GJ 667C was previously detected in 2010, but the finding was never published, Vogt added. This planet, called GJ 667Cb, takes 7.2 days to circle the star but its location makes it far too hot to sustain liquid water on its surface. "It's basically glowing cinders, or a well-lit charcoal," Vogt said. "We know about a lot of these, but they're thousands of degrees and not places where you could live." But, the newly detected GJ 667Cc planet is a much more intriguing candidate, he said. "When a planet gets bigger than about 10 times the size of the Earth, there's a runaway process that happens, where it begins to eat up all the gas and ice in the disk that it's forming out of and swells quickly into something like Uranus, Jupiter or Saturn," Vogt explained. "When you have a surface and the right temperature, if there's water around, there's a good chance that it could be in liquid form. This planet is right in that sweet spot in the habitable zone, so we've got the right temperature and the right mass range." Preliminary observations also suggest that more planets could exist in this system, including a gas giant planet and another super-Earth that takes about 75 days to circle the star. More research will be needed to confirm these planetary candidates, as well as to glean additional details about the potentially habitable super-Earth, the scientists said. Finding nearby alien planets To make their discovery, the researchers used public data from the European Southern Observatory combined with observations from the W.M. Keck Observatory in Hawaii and the new Carnegie Planet Finder Spectrograph at the Magellan II Telescope in Chile. Follow-up analyses were also made using a planet-hunting technique that measures the small dips, or wobbles, in a star's motion caused by the gravitational tug of a planet. "With the advent of a new generation of instruments, researchers will be able to survey many M dwarf stars for similar planets and eventually look for spectroscopic signatures of life in one of these worlds," Anglada-Escudé said in a statement. Anglada-Escudé was with the Carnegie Institution for Science when he conducted the research, but has since moved on to the University of Gottingen in Germany. With the GJ 667C system being relatively nearby, it also opens exciting possibilities for probing potentially habitable alien worlds in the future, Vogt said, which can't easily be done with the planets that are being found by NASA's prolific Kepler spacecraft. "The planets coming out of Kepler are typically thousands of light-years away and we could never send a space probe out there," Vogt said. "We've been explicitly focusing on very nearby stars, because with today's technology, we could send a robotic probe out there, and within a few hundred years, it could be sending back picture postcards." You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook. |
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Oh, thank all imaginable deities. Now I can sleep at night. ;-)
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Vertices of Venus, Jupiter and the Moon on 2/25 and 2/26
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Interesting article from Scientific Reports
Communication during sex among female bonobos: effects of dominance, solicitation and audience
"Bonobo females frequently form close bonds, which give them social power over other group members. One potential mechanism to facilitate female bonding is the performance of sexual interactions. Using naturalistic observations and experiments, we found various patterns that determined female-female sexual interactions. First, while low-ranked females interacted with all females, sexual interactions between high-ranked females were rare. Second, during genital contacts, females sometimes produced ‘copulation calls’, which were significantly affected by the rank of the caller and partner, as well as the solicitation direction. Third, there was a significant effect of the alpha female as a bystander, while variables relating to physical experience had no effects. Overall, results highlight the importance of sexual interactions for bonobo female social relations. Copulation calls are an important tool during this process, suggesting that they have become ritualised, beyond their reproductive function, to serve as broader social signals in flexible and potentially strategic ways." sources: Clay, Z. and Zuberbühler, K. (2012). Communication during sex among female bonobos: effects of dominance, solicitation and audience. Scientific Reports, 2:291. http://www.nature.com/srep/2012/1203...srep00291.html |
Science Casts: Auroras Underfoot
How can I resist the opportunity to once again post a video that includes the term "aurora mass ejections"? And now I know what other career tract I want to pursue - "astrophotographer."
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http://news.yahoo.com/ethiopias-magn...140401541.html
Magnetic strips hold clues to oceans formation. |
Seems we are not quite ready for long period space travels...
"Space flight linked to eye, brain problems
CBC News Space travel hurts eyes, brain Astronauts who have spent prolonged periods in the zero gravity of space tend to show eye abnormalities linked to pressure around the brain, another study has confirmed. The new study, which involved magnetic resonance imaging of the eyes and brains of 27 astronauts – a larger sample than previous studies — also found abnormalities in the pituitary gland and its connection to the brain in three cases. The gland, found at the base of the brain, secretes and stores a number of important hormones that regulate growth, metabolism and reproduction. The findings, published online in the journal Radiology on Tuesday, may point to a "hypothetical risk factor and potential limitation to long-duration space travel," said study co-author Dr. Larry Kramer, a professor of diagnostic and interventional imaging at the University of Texas Medical School at Houston, in a statement. That means they could pose a problem on future missions to places such as Mars. An earlier study on eye problems in astronauts suggested that the issues might be caused by fluid shifting toward the head during extended periods of time in microgravity. William J. Tarver, chief of the flight medicine clinic at NASA's Johnson Space Center, said in a statement that the U.S. space agency has "placed this problem high on its list of human risks, has initiated a comprehensive program to study its mechanisms and implications, and will continue to closely monitor the situation." Astronauts have complained for decades about vision problems such as blurriness following trips into space. A recent NASA survey of 300 astronauts found correctible near and distance vision problems in 48 per cent of astronauts who had been on extended missions and 23 per cent of those who had been on brief missions. In some cases, they lasted for years after the astronauts returned to Earth. Fluid shifting toward head causes problems In the new study, the astronauts had spent an average of 108 days in space. Their eye abnormalities were similar to those seen in patients on Earth with idiopathic intracranial hypertension. Patients with the condition have increased pressure around their brains for no apparent reason. Among the astronauts in the study: 33 per cent had expansion of the space filled with cerebral spinal fluid that surrounds the optic nerve, which connects the eye to the brain. 22 per cent had flattening of the rear of the eyeball. 15 per cent had bulging of the optic nerve. 11 per cent had changes in the pituitary gland and its connection to the brain. An earlier NASA-sponsored study of seven astronauts, published last November in the journal Ophthalmology, found similar abnormalities and also noted that they were similar to those experienced by patients on Earth suffering from pressure in the head. But it noted that astronauts did not experience symptoms usually associated with that problem on Earth, such as chronic headache, double vision or ringing in the ears. The earlier study suggested that the problems might be caused by fluid shifting toward the head during extended periods of time in microgravity. This could result in abnormal flow of spinal fluid around the optic nerve, changes in blood flow in the vessels at the back of the eye, or chronic low pressure within the eye, the researchers said." Source: www.cbc.ca http://www.cbc.ca/news/technology/st...-problems.html |
I might rething the use of a french idiomatic expression!!
In french, when we want to show skepticism or that we do not believe that an event will occur, we use the expression: "quand les poules auront des dents". It translates to: when hens will have teeth. It is the equivalent of the english expression of "When pigs fly". But behold...
Atavism: Embryology, Development and Evolution By: Jill U. Adams, Ph.D. & Kenna M. Shaw, Ph.D. (Nature Education) © 2008 Humans do not have tails, but do we have “what it takes” for a tail? Hens don’t have teeth, but they have the genes for it. With atavism, it is as if our genomes serve as archives of our evolutionary past. Hens do not have teeth, and humans do not have tails. Research suggests we have "what it takes" for a tail, and hens, indeed, have the genes that encode for a toothy grin; however, only in very rare situations do these traits manifest themselves as a phenotype. This phenomenon is called atavism—the reappearance of a trait that had been lost during evolution. Our genes do not determine who we are, but with atavism, they can sometimes serve as reminders of our evolutionary past. Traits that appear or disappear over time are not the result of newly mutated genes encoding defective versions of the proteins associated with teeth or tails, nor are they caused by a loss of existing genes. Instead, a growing body of experimental evidence has shown such traits reflect changes in how, where, and when these genes are expressed. Examples of "Teeth" in Chicken Hen's teeth: As rare as we thought? © 2006 Nature Publishing Group Bajaj, Arveen. Hen's teeth. British Dental Journal 200, 187. All rights reserved. Even though birds lost teeth as physical structures between 60 and 80 million years ago, several studies have shown that those tissues within birds that would normally produce teeth still retain the potential to do so. For example, in 1821, Geoffrey St. Hilaire was the first scientist to publish the observation that some bird embryos exhibited evidence of tooth formation, but his contemporaries considered his work flawed. Since then, however, many investigators have unearthed molecular evidence that the genes involved in odontogenesis (tooth development) are indeed retained in chickens. A primary step in reaching this conclusion occurred when researchers exposed chick jaws to certain proteins known to cue tooth development. As a result, toothlike structures grew, and other tooth markers were expressed (Chen et al., 2000). These findings were artificial in the sense that the prompting signal was experimentally administered; nonetheless, they were significant in showing that a chicken's jaw could produce teeth if specific conditions were present. Despite this discovery, no one had yet demonstrated that chickens could develop teeth without external cues. This situation soon changed, however, when researchers Matthew Harris (a graduate student at the time) and John Fallon launched a study involving chickens with a particular kind of autosomal recessive mutation (Harris et al., 2006). These chickens, designated by the abbreviation ta2, displayed signs reminiscent of early tooth development. The researchers needed a positive control with which to compare their hens' teeth-that is, a closely related animal in which teeth occur. Typically, the nonmutant or "wild-type" phenotype serves as a control in gene mutation experiments, but this was an exceptional case in that the wild-type chicken doesn't have teeth. Harris and Fallon specifically needed to compare the structures they believed to be teeth in their ta2 mutant chickens with the next best thing—the closest ancestor to the chicken that still has teeth—which in this case was the archosaur, otherwise known as the common crocodile. Therefore, the researchers examined the expression of several biomarkers in wild-type chicken embryos, ta2 mutant embryos, and crocodile embryos. They found that the ta2 mutant oral cavities appeared developmentally closer to those of the crocodiles than to those of their wild-type siblings. These results thus demonstrated that all the genetic pieces to the tooth-building puzzle exist in chickens, but the directions have evolved to tell those pieces to do something different over the last 80 million years. Atavism and Human Tails True examples of atavism, like the ta2 chicken, are data points indicative of common ancestry between species. In the case of human beings, the presence of a tail is a striking example of such ancestry. Many cases of people born with "tails" exist in the medical literature, but it is not always clear whether these appendages are "true" tails or not. In some instances, they are actually "pseudotails," or malformations that just happen to be located near a person's tailbone. True tails, however, result from a particular type of error during fetal development. source: http://www.nature.com/scitable/topic...-evolution-843 |
http://news.yahoo.com/mysterious-chi...150805074.html
New human species fossils found in cave in China. |
Neutrinos not faster than light
Neutrinos not faster than light
"ICARUS experiment contradicts controversial claim. Geoff Brumfiel 16 March 2012 The ICARUS detector in Gran Sasso, Italy, has confirmed that neutrinos travel no faster than the speed of light. INFN Gran Sasso National Laboratory Neutrinos obey nature's speed limit, according to new results from an Italian experiment. The finding, posted to the preprint server arXiv.org, contradicts a rival claim that neutrinos could travel faster than the speed of light. Neutrinos are tiny, electrically neutral particles produced in nuclear reactions. Last September, an experiment called OPERA turned up evidence that neutrinos travel faster than the speed of light (see 'Particles break light speed limit'). Located beneath the Gran Sasso mountain in central Italy, OPERA detected neutrinos sent from CERN, Europe's premier particle-physics laboratory near Geneva, Switzerland. According to the group's findings, neutrinos made the 731-kilometre journey 60 nanoseconds faster than predicted if they had travelled at light speed. The announcement made international headlines, but physicists were deeply sceptical. The axiom that nothing travels faster than light was first formulated by Albert Einstein and is a cornerstone of modern physics. OPERA defended its announcement, saying that it could find no flaw in its measurement. Now another experiment located just a few metres from OPERA has clocked neutrinos travelling at roughly the speed of light, and no faster. Known as ICARUS, the rival monitored a beam of neutrinos sent from CERN in late October and early November of last year. The neutrinos were packed into pulses just 4 nanoseconds long. That meant that the timing could be measured far more accurately than the original OPERA measurement, which used 10-microsecond pulses. "Our results are in agreement with what Einstein would like to have," says Carlo Rubbia, the spokesperson for ICARUS and a Nobel prizewinning physicist at CERN. Neutrinos measured by the experiment arrived within just 4 nanoseconds of the time that light travelling through a vacuum would take to cover the distance, well within the experimental margin of error. Because the pulses from CERN were so short, ICARUS only measured seven neutrinos during the late autumn run, but Rubbia says that the relatively low number does not matter. "How many times do you have to say 'zero' to make sure it's zero?" he asks. The findings are yet another blow to OPERA, which was already under intense scrutiny from the wider experimental community. Almost as soon as the announcement was made, physicists began trying to poke holes in the OPERA analysis, and on 23 February researchers from within the OPERA team announced that they had uncovered possible timing problems with their original measurements (see 'Timing glitches dog neutrino claim'). Those problems could have led to the 60-nanosecond discrepancy. Dario Autiero, a physicist at the Institute of Nuclear Physics in Lyons, France, and physics coordinator for OPERA, welcomes the latest result. He notes that OPERA continued to detect faster-than-light neutrinos in October and November, when the shorter pulses were used. The team continues to search for possible sources of error, he says. For some, the new measurements settle the matter once and for all. "The OPERA case is now conclusively closed," says Adam Falkowski, a theoretical physicist at the University of Paris-South in Orsay, France. But Rubbia says that he is still awaiting further measurements set to be made later in the spring by OPERA, ICARUS and two other experiments inside Gran Sasso. "Had we found 60 nanoseconds, I would have sent a bottle of champagne to OPERA," Rubbia says. But as it stands, he suspects he will be toasting Einstein. "It's quite a relief, because I'm a conservative character," he says." source: http://www.nature.com/news/neutrinos...-light-1.10249 |
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