Xenophilia (True Strange Stuff)

Blog of the real Xenophilius Lovegood, a slightly mad scientist

Archive for December 16th, 2011

DNA death predictors: What do they really tell you?

Posted by Anonymous on December 16, 2011

http://www.navigenics.com/static/images/visitor/scientist-microscope.jpg… gene-sequencing companies such as 23andme, deCodeMe and Navigenics can do a quick scan of your risk of developing everything from lung cancer to multiple sclerosis. Now two new firms are offering to tell us how well we are ageing, based on an analysis of structures at the ends of our chromosomes called telomeres.

If these developments continue, a person’s lifespan could become as quantifiable as the shelf life of a carton of milk. So instead of parading around blissfully unaware of how long we have left, we could find out our own use-by dates. For some, this knowledge would be a burden, while others may be glad of the chance to plan their future. But whether you find the prospect of being able to foretell your own death terrifying or enticing, how realistic is it? Are these new tests really a game changer? After all, we have long been able to test for life-threatening factors such as high cholesterol and blood pressure. … According to Timothy Caulfield, a bioethicist and lawyer at the University of Alberta in Edmonton, Canada, who has been looking into how people react to tests like these … “People don’t seem to do much with this risk information,” he says. “They don’t freak out. And they don’t start exercising more, eating better or getting more screening.” This should not surprise us, he adds, since we have never responded much to other more traditional predictive information, such as weight, blood pressure and cholesterol levels. …

At 23andme, I was tested for a “longevity trait” identified by the company. Apparently I don’t possess it and have merely typical odds of living to age 95 or 100. … At best, the particular genes you carry will only ever explain about 25 per cent of your propensity to live a long life, says Slagboom. So can the new telomere-based tests do any better?

Like the plastic tips at the ends of shoelaces, telomeres keep your chromosomes from fraying and getting tangled up with one another. Every time chromosomes replicate during cell division the telomeres get a bit shorter. This process starts even before you are born and about a third of their length is lost in the first 20 years of life, says Calvin Harley, president and chief scientific officer of Telome Health, based in Menlo Park, California. As we age, the shortening continues – by about 9 per cent each decade, on average. It is not clear whether some people have a higher natural rate of loss but we do know that telomeres respond to lifestyle, and that smoking, heavy drinking, obesity and stress can all shorten them a little more quickly. That is bad news because short telomeres are associated with earlier death. One study by Richard Cawthon at the University of Utah, for instance, looked at their lengths in adults over 60. People whose telomeres were shorter than average for their age cohort were 3.18 times more likely to die of heart problems and 8.54 times more likely to die from infectious disease, than those who had longer than average telomeres for their age (The Lancet, vol 361, p 393).

It is easy to see why people trying to divine their own personal expiration date would be interested in knowing how long their telomeres are, and how they compare with other people of the same age. This is exactly the information offered by a Spanish company called Life Length, based in Madrid, which began selling its €500 test a year ago. Telome Health had also planned to offer a telomere test. Back in May, co-founder Elizabeth Blackburn – a Nobel laureate for her discovery of telomerase, the enzyme that stimulates telomere elongation – told New Scientist its test would be available for under $200 by the end of the year. However, Harley now says it will only be used for research purposes for the foreseeable future. …

Carol Greider at Johns Hopkins University in Baltimore, Maryland, who shared the Nobel prize with Blackburn, points out that there is no consensus yet on the best technique for measuring telomeres. In fact, her work on mice found no correlation between telomere length and lifespan (Nucleic Acids Research, vol 28, p 4474) and she argues that little is known about how telomere length affects health and longevity in humans. “There’s a very wide distribution of telomere lengths,” she says, and they can vary a lot for any given age. If you fall below the first percentile, you are clearly at risk for age-related diseases, she adds, but the science hasn’t really established much beyond that. Greider concludes that telomere testing for the general public is premature. …

via DNA death predictors: What do they really tell you? – health – 15 December 2011 – New Scientist.

Posted in Biology, Health, Survival | Leave a Comment »

Katehi, legislators agree: Unrest tied to funding shortfall

Posted by Anonymous on December 16, 2011

Assemblyman Marty Block called it the “elephant in the room.” But he, other lawmakers and Chancellor Linda P.B. Katehi had no trouble talking about that elephant during a joint legislative hearing earlier this week on student unrest.

“The root to all of this, frankly, is the underfunding of higher education,” said Block, D-San Diego, chair of the Assembly Higher Education Committee, which joined with the Senate Education Committee in holding the Dec. 14 hearing.

“Budget cuts have been horrible, and, frankly, we are only dealing with the resources that the taxpayers of California give us,” Block said. “Higher education has absorbed the brunt of the burden already.”

The lawmakers — addressing the response by campus police to recent protests at UC Davis, UC Berkeley and California State University Long Beach — took testimony from experts in policing, a representative of the American Civil Liberties Union, students, and UC and California State University administrators, including Katehi and UC President Mark G. Yudof.

In her prepared remarls, Katehi emphasized the issues that underlie the protests.

“Our students are increasingly frustrated and angry about reductions in state support for higher education,” the chancellor said. “They are frustrated and angry about repeated tuition increases. They are worried about how they will repay their loans and find jobs when they graduate.”

Assemblywoman Mariko Yamada, D-Davis, a member of the Higher Education Committee, issued a news release in which she said the protests “were born out of outrage and hopelessness that many feel are due to the increasing disinvestment in higher education.”

$100 million ‘trigger’ cut

The hearing came the day after Gov. Jerry Brown announced a “trigger” cut of $100 million in UC funding, on top of the $650 million that the state already sliced from UC’s budget for 2011-12. See box for UC’s response.

A shortfall in state revenue triggered the new cut, as required in the budget deal that Brown and the Legislature crafted earlier this year.

Voicing optimism for a better deal for 2012-13, Assemblywoman Nancy Skinner, D-Berkeley, told the legislative hearing Dec. 14: “Higher education should be a higher priority of the California Legislature.”

Katehi has committed to redoubling her advocacy at the Capitol, telling the lawmakers: “We all need to work together to make higher education more affordable and accessible, or there will be continued frustration from students, both from those who protest, and from those who only want to go to class without distraction.

“They are justifiably frustrated, and so am I.”

UC Davis’ latest round of protests began Nov. 15 with rallies and marches that led to an “occupy”-style encampment on the Quad, in violation of campus policy. Police went in Nov. 18 to remove the equipment, resulting in the arrest of 10 protesters — nine of them students — and the pepper-spraying of 11 people.

“Did I direct the police to use pepper spray? The answer is no,” Katehi told the lawmakers. “Did I direct police to use force? The answer is no.”

Block asked her what she would have done differently Nov. 18, drawing this response: “If I knew the police could not remove the tents peacefully, we would not have removed them.”

As she has done previously in a number of talks with faculty, students and staff, the chancellor accepted responsibility and vowed to make reforms to ensure there students can safely engage in peaceful civil disobedience.

She noted the five investigations that are under way to determine what happened on Nov. 18 and why.

Among them is UC’s review of police policies and procedures on all the campuses. UC President Mark G. Yudof told lawmakers his intent is not to micromanage chancellors or campus police.

“Nonetheless, the recent incidents make clear that the time has come to take strong action to recommit to the ideal of peaceful protest.”

Assemblywoman Yamada agreed: “Something positive will come out of this.” …

via UC Davis News & Information :: Dateline :: Katehi, legislators agree: Unrest tied to funding shortfall.

Funding shortfall. Yes… keep going. Why? California is broke. Yes… keep going. Why? Irresponsible borrowing over the years. Yes… keep going. What were we borrowing money for? … uh …. uh …. War.

Bingo. Until you talk about the war, no, you have not yet talked about the elephant in the room. (See my past entries showing how California pays more than its share, more billions of dollars than have been so far cut for education, for the wars we are fighting. )

Posted in Education, Money, Survival, War | 3 Comments »

Satellite spots China’s first aircraft carrier at sea

Posted by Anonymous on December 16, 2011

Alan Boyle – A commercial satellite operator says it has captured a rare image of China’s first aircraft carrier as it sailed through the Yellow Sea, after going through an exercise that’s the 21st-century equivalent of finding a needle in a haystack.

DigitalGlobe said the aircraft carrier showed up on a cloud-filled picture snapped on Dec. 8 by its polar-orbiting QuickBird satellite from a height of 280 miles (450 kilometers). An analyst spotted the ship while checking the image on Tuesday, said Stephen Wood, the director of the company’s analysis center.

… DigitalGlobe said this picture was taken during the carrier’s second sea trial, approximately 62 miles (100 kilometers) south-southeast of the port of Dalian. Wood said the picture indicates that the ship is “moving at a decent rate of speed, which would be expected in the middle of the ocean.” The U.S. military could no doubt glean more information about the Shi Lang’s status, from QuickBird’s pictures as well as from classified, higher-resolution imagery.

via PhotoBlog – Satellite spots China’s first aircraft carrier at sea.

Posted in Technology, War | Leave a Comment »

Canada Begins Hearings on Salmon Virus

Posted by Anonymous on December 16, 2011

The fate of wild salmon is a sensitive topic in the Pacific Northwest and arguments often end up in court in the United States, whether over threats to endangered fish by hydroelectric dams or sea lions swallowing them along their migration routes.

But on Thursday, a new and particularly bitter dispute began playing out in a very different kind of judicial venue across the Canadian border: a provincial Supreme Court justice held a hearing into questions of whether a potentially lethal virus had been detected in wild Pacific salmon — and whether the Canadian government was responding adequately.

The virus, infectious salmon anemia, has devastated farmed Atlantic salmon stocks in Chile and elsewhere. Some conservationists and scientists have long worried that the virus would spread from farmed fish to wild ones. Those fears escalated in October, when opponents of British Columbia’s ambitious farmed Atlantic salmon program, which is heavily promoted by the government, presented lab results they said showed an asymptomatic form of the virus in wild Pacific salmon.

Several more reports of the virus have emerged in the past two months, including a draft paper suggesting that the virus was detected as early as 2002 but not revealed by the government, further angering farming opponents.

The developments have prompted passionate debate on both sides of the border, with reaction veering from accusations that the Canadian government is covering up evidence of the disease to claims by Canadian officials that the reports are based on poor science.

Some scientists have suggested that a strain of the virus may have been present in wild Pacific salmon for many years as a “host pathogen,” without causing a disease outbreak, and that it may never pose a risk. …

via Canada Begins Hearings on Salmon Virus – NYTimes.com.

Posted in Biology, Food | Leave a Comment »

Experiments explain why almost all multicellular organisms begin life as a single cell

Posted by Anonymous on December 16, 2011

Close family ties keep cheaters in check, study findsDicty: An amoeba that must succeed at both single-celled and multicellular living to pass on its genes.

Any multicellular animal, from a blue whale to a human being, poses a special difficulty for the theory of evolution. Most of the cells in its body will die without reproducing, and only a privileged few will pass their genes to the next generation.

How could the extreme degree of cooperation multicellular existence requires ever evolve? Why aren’t all creatures unicellular individualists determined to pass on their own genes?

Joan Strassmann, PhD, and David Queller, PhD, a husband and wife team of evolutionary biologists at Washington University in St. Louis, provide an answer in the Dec. 16 issue of the journal Science. Experiments with amoebae that usually live as individuals but must also join with others to form multicellular bodies to complete their life cycles showed that cooperation depends on kinship.

If amoebae occur in well-mixed cosmopolitan groups, then cheaters will always be able to thrive by freeloading on their cooperative neighbors. But if groups derive from a single cell, cheaters will usually occur in all-cheater groups and will have no cooperators to exploit.

The only exceptions are brand new cheater mutants in all-cooperator groups, and these could pose a problem if the mutation rate is high enough and there are many cells in the group to mutate. In fact, the scientists calculated just how many times amoebae that arose from a single cell can safely divide before cooperation degenerates into a free-for-all.

The answer turns out to be 100 generations or more.

So population bottlenecks that kill off diversity and restart the population from a single cell are powerful stabilizers of cellular cooperation, the scientists conclude.

In other words our liver, blood and bone cells help our eggs and sperm pass on their genes because we passed through a single-cell bottleneck at the moment of conception. …

via Experiments explain why almost all multicellular organisms begin life as a single cell.

Posted in Biology | Leave a Comment »

U.S. Suspends Use of Chimps in New Research

Posted by Anonymous on December 16, 2011

Patin, Emslee and ArielleThe National Institutes of Health on Thursday suspended all new grants for biomedical and behavioral research on chimpanzees and accepted the first uniform criteria for assessing the necessity of such research. Those guidelines require that the research be necessary for human health, and that there be no other way to accomplish it.

In making the announcement, Dr. Francis S. Collins, the director of the N.I.H., said that chimps, as the closest human relatives, deserve “special consideration and respect” and that the agency was accepting the recommendations released earlier in the day by an expert committee of the Institute of Medicine, which concluded that most research on chimpanzees was unnecessary.

The report and the quick response by the N.I.H. do not put an end to research on chimps, but they were claimed as victories by animal welfare groups that have long been fighting for a ban on such research, arguing that chimps should not be subjected to experimental use. They said that the move was a step toward eventually ending chimp research, already a tiny segment of federal research.

Jeffrey Kahn, chairman of the Institute of Medicine committee that produced the report and a professor of bioethics and public policy at Johns Hopkins University, said the group’s recommendations would make it harder to use chimps in research.

“What we did was establish a set of rigorous criteria that set the bar quite high for use of chimpanzees in biomedical or behavioral research,” he said. He also said that, in effect, the writing was on the wall: “One of the important themes in the committee report is that there is a trajectory toward decreasing necessity for the use of chimps in biomedical and behavioral research.”

Wayne Pacelle, president of the Humane Society of the United States, which is strongly opposed to any experimentation on chimpanzees, said, “We’re tremendously encouraged.” He said the report’s “overarching conclusion was that chimps are largely unnecessary” for research, and that the report and N.I.H. action could influence two other continuing efforts to stop research on chimps.

One is the Great Ape Protection and Cost Savings Act of 2011, now before both houses of Congress. Another is a petition before the federal Fish and Wildlife Service to declare captive chimpanzees endangered, as wild chimpanzees are. The exemption has allowed research to continue and permits the use of chimpanzees in entertainment and as pets.

“ ‘Endangered’ stops all those uses,” Mr. Pacelle said, and the report’s skeptical assessment of the value of chimps in research would provide support for the Fish and Wildlife Service to categorize all chimps as endangered. …

via U.S. Suspends Use of Chimps in New Research – NYTimes.com.

Posted in Biology | Leave a Comment »

Comet “Harpoon” Being Test Fired in NASA Lab

Posted by Anonymous on December 16, 2011

A prototype of a comet harpoon.An explosive-powered harpoon designed to skewer a comet would be the easiest way to grab a chunk of the icy body for study back on Earth, according to NASA researchers who are currently testing the device.

Since comets have very low gravity—maybe a millionth that of Earth’s—landing a probe on one can be a challenge.

But getting close to a comet, even within 15 feet (5 meters) or so, is no problem, said project leader Joe Nuth, of NASA’s Goddard Space Center in Maryland.

“Let’s say you’re 10 meters [33 feet] away from a comet [with all engines and control systems] turned off. It would still take you half an hour to fall to the surface of a large comet,” Nuth said. “There’s plenty of margin for error.”

Hovering over the comet, “you can control [the craft] with just a small puff of gas—really just a sneeze.”

The hypothetical harpooning mission would approach a comet when the object is 288 million miles (463 million kilometers) away from the sun.

At this distance, the comet would still be in a region where a spacecraft’s solar arrays could get enough sunlight to generate propulsion.

But solar radiation wouldn’t yet be causing large amounts of the comet’s ices to vaporize, creating a thick halo of debris—the coma—that could interfere with the spacecraft’s solar arrays and navigation system.

Once the spacecraft is hovering near the comet, the harpoon would be fired with an explosive charge deep into the comet’s nucleus.

The harpoon would have an internal sample-collection chamber that would close around a chunk of comet and detach from the harpoon’s tip, sailing back to the spacecraft, which would eventually return to Earth.

Right now Goddard scientists are testing a proof-of-concept harpoon by firing it in the lab from a six-foot-tall (almost two-meter-tall) crossbow. …

via Comet “Harpoon” Being Test Fired in NASA Lab.

Posted in Space, Technology | Leave a Comment »

Heavy Rainfall Can Cause Huge Earthquakes

Posted by Anonymous on December 16, 2011

People cross a makeshift bridge over floodwater from Typhoon Morakot in Taiwan.Heavy rainfall can trigger earthquakes in what one scientist calls “disaster triggering disaster.”

Shimon Wdowinski, of the University of Miami in Florida, first noticed a connection between storms and earthquakes last year.

The devastating magnitude 7.0 earthquake that hit Haiti in early 2010 came only 18 months after Haiti had been deluged by several hurricanes and tropical storms. (See “Haiti Earthquake Anniversary: Pictures Show Slow Recovery.”)

And another large earthquake, a magnitude 6.4 temblor that rocked Taiwan in 2009, occurred only seven months after the area had been hit by Typhoon Morakot, which dropped 9.5 feet (2.9 meters) of rain in five days. Hurricanes are called typhoons in parts of Asia.

To put that in perspective, “that’s about five times the average [annual] rainfall of San Francisco … in five days,” Wdowinski said last week at a meeting of the American Geophysical Union in San Francisco.

To test the rainfall-earthquake link, Wdowinski dug through the past 50 years of earthquake and weather records for Taiwan, an island that experiences a lot of severe rainstorms and earthquakes.

He found that a magnitude 7.6 earthquake had struck in 1999, only three years after Typhoon Herb soaked Taiwan with 6.6 feet (2 meters) of rain.

Overall, his analysis revealed that Taiwan’s large earthquakes—deemed as magnitude 6 and higher—were five times more likely to occur within four years after such storms than if the storms had had no effect.

The weight of the water itself does not trigger the earthquake—rather, it’s the ensuing erosion from landslides, which subsequent storms steadily wash into the sea.

“There’s less stress [on the underlying rocks], and it’s easier for the fault to move,” he said. “These are small changes, but are apparently enough to trigger the earthquake.”

via Heavy Rainfall Can Cause Huge Earthquakes.

Posted in Earth | Leave a Comment »

Dinosaurs with killer claws yield new theory about evolution of flight

Posted by Anonymous on December 16, 2011

New research from Montana State University’s Museum of the Rockies has revealed how dinosaurs like Velociraptor and Deinonychus used their famous killer claws, leading to a new hypothesis on the evolution of flight in birds.

“This study is a real game-changer,” said lead author Fowler. “It completely overhauls our perception of these little predatory dinosaurs, changing the way we think about their ecology and evolution.”

The study focuses on dromaeosaurids; a group of small predatory dinosaurs that include the famous Velociraptor and its larger relative, Deinonychus. Dromaeosaurids are closely related to birds, and are most famous for possessing an enlarged sickle-claw on digit two (inside toe) of the foot. Previous researchers suggested that this claw was used to slash at prey, or help climb up their hides, but the new study proposes a different behavior.

“Modern hawks and eagles possess a similar enlarged claw on their digit 2’s, something that hadn’t been noted before we published on it back in 2009,” Fowler said. “We showed that the enlarged D-2 claws are used as anchors, latching into the prey, preventing their escape. We interpret the sickle claw of dromaeosaurids as having evolved to do the same thing: latching in, and holding on.”

As in modern birds of prey, precise use of the claw is related to relative prey size.

“This strategy is only really needed for prey that are about the same size as the predator; large enough that they might struggle and escape from the feet,” Fowler said. “Smaller prey are just squeezed to death, but with large prey all the predator can do is hold on and stop it from escaping, then basically just eat it alive. Dromaeosaurs lack any obvious adaptations for dispatching their victims, so just like hawks and eagles, they probably ate their prey alive too.” …

via Dinosaurs with killer claws yield new theory about evolution of flight.

Note that Jurassic Park got it wrong, velociraptor had feathers.

A new look at some old bones have shown that velociraptor, the dinosaur made famous in the movie Jurassic Park, had feathers. The discovery was made by paleontologists at the American Museum of Natural History and the Field Museum of Natural History.Scientists have known for years that many dinosaurs had feathers. Now the presence of feathers has been documented in velociraptor, one of the most iconic of dinosaurs and a close relative of birds.

… “The more that we learn about these animals the more we find that there is basically no difference between birds and their closely related dinosaur ancestors like velociraptor,” said Mark Norell, a Curator in the Division of Paleontology at the American Museum of Natural History and co-author on the study. “Both have wishbones, brooded their nests, possess hollow bones, and were covered in feathers. If animals like velociraptor were alive today our first impression would be that they were just very unusual looking birds”. ….

Posted in Archaeology, Biology | Leave a Comment »

Cloud suicide will wake black hole sleeping giant

Posted by Anonymous on December 16, 2011

<img class="alignleft" title="The suicidal gas cloud is due to break up in 2013 (Image: ESO/MPE/Marc Schartmann)” src=”http://www.newscientist.com/data/images/ns/cms/dn21288/dn21288-1_300.jpg&#8221; alt=”The suicidal gas cloud is due to break up in 2013 (Image: ESO/MPE/Marc Schartmann)” />The sleeping giant at the centre of the Milky Way is about to wake up. A suicidal gas cloud is heading towards the galaxy’s supermassive black hole, which will probably swallow the cloud, generating enormous flares of radiation that could help explain why the black hole is normally so placid.

The doomed cloud was a surprise to astronomers. “We have been looking at the galactic centre for 20 years, but mainly to observe the motion of stars,” says Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany.

Genzel’s colleague Stefan Gillessen spotted the cloud in images from the Very Large Telescope array in Chile, taken in March this year. It is an unusually dense cloud, not much bigger than our solar system and carrying about three times the mass of Earth.

The team realised that the cloud also appears in earlier images, giving them a sequence that reveals its path. It is moving at almost 2500 kilometres per second towards our galaxy’s black hole, Sagittarius A*.

At present Sagittarius A* is strangely quiet, unlike quasars, the hyperactive black holes that emit huge amounts of radiation, fuelled by inflowing gas. Our black hole gets much less gas, and for some reason this starvation state makes it much less efficient than a quasar, producing only a thousandth as much radiation per kilogram of fuel.

While a star would just sail past our black hole unscathed, the loose mass of gas heading towards it is more vulnerable. It is already being stretched out by the black hole’s gravity, and when it gets closer in 2013 it will plough into the halo of hot gas around the hole.

That should send shockwaves through the cloud to heat it to several million degrees, and according to the group’s simulations the gaseous collision will shred the cloud into filaments. This turmoil may mean that much of the cloud ends up swirling right down into the black hole. …

There’s no danger of the active black hole harming Earth….

via Cloud suicide will wake black hole sleeping giant – space – 14 December 2011 – New Scientist.

Posted in Space | Leave a Comment »

 
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