The 6 Most Gigantic Everything in the History of War
|12:45:03 AM, Tuesday, September 20, 2011|
"In the words of Mahatma Gandhi, "War makes people act like dicks." We don't want to glorify war or otherwise portray it as something other than terrible. Yet, war makes people think big, and sometimes you have to sit back and be amazed by what humans can accomplish when they really, really want to kill each other..."
How Common Are Earth-Moon Planetary Systems?
|12:10:54 AM, Tuesday, September 20, 2011|
"Sebastian Elser, Prof. Ben Moore and Dr. Joachim Stadel of the University of Zurich, Switzerland, in cooperation with Ryuji Morishima of NASA's Jet Propulsion Laboratory, tried to estimate how common Earth-Moon planetary systems are. They have found that 1 in 12 Earth-like planets probably hosts a Moon-like satellite. Since the Moon might have played an important role in the history of life on Earth, this estimate is important concerning the search for habitable planets.
Earth's Moon might have played an important role in the development and evolution of life on Earth. The Moon was formed via a giant impact in which a Mars-size projectile collided with the young Earth. The ejected material accumulated in orbit around our planet and formed the Moon. After its formation, the Moon was much closer to Earth than it is today, which caused high tides several times per day. This may have helped promote the very early evolution of life. In addition, a stable climate of more than a billion years may be essential to guarantee a suitable environment for life. But without its satellite, Earth would suffer chaotic variations of the direction of its spin axis, which would in turn result in dramatic variations of the climate.
Therefore, concerning the habitability of extrasolar planets, it is reasonable to ask: How common are Earth-Moon planetary systems? Sebastian Elser, Prof. Ben Moore and Dr. Joachim Stadel of the University of Zurich, Switzerland, along with Ryuji Morishima of NASA's Jet Propulsion Laboratory in Pasadena, California, ran a large set of N-body simulations to study the formation of the rocky planets in our solar system via the collisional growth of thousands of small rocky bodies in a disk around the Sun.
They identified numerous satellite-forming collisions during this process and estimated the masses of the generated companions. Moreover, they took into account the orbital evolution of the satellites, since tidal forces change the spin and orbit of a satellite and can cause it to be lost within a few thousand years in the most extreme cases.
Finally, they studied the subsequent collision history, since giant impacts after the epoch of satellite formation may pose a challenge to the survival of a satellite. They find that Earth-Moon planetary systems occur relatively frequently, with more than 1 in 12 terrestrial planets hosting a massive moon. Uncertainties in the study result in a range of 1 in 4 to 1 in 45. Further work and more N-body simulations are needed to obtain more precise results.
This work is being presented at the Extreme Solar Systems II conference in Jackson, Wyoming, and appears in the August 2011 issue of Icarus..."
World's Biggest Sperm Bank, Cryos, Tells Redheads: We Don't Want Your Semen
|10:25:04 PM, Monday, September 19, 2011|
"Demand for ginger-haired donors is so low that Cryos International says they needn't bother donating.
"There are too many redheads in relation to demand," Ole Schou, the director of Cryos, told the Danish newspaper, Ekstrabladet, according to London's Telegraph.
Men with scarlett manes sell "like hot cakes" in Ireland, Schou said, but that's about it.
"I do not think you choose a redhead, unless the partner - for example, the sterile male - has red hair, or because the lone woman has a preference for redheads," he said, the Telegraph reported. "And that's perhaps not so many, especially in the latter case."
Men with brown hair and brown eyes are very popular, Schou noted.
Cryos ships sperm to more than 65 countries around the world, and donors can score up to $500 for their semen..."
-- 'Cause no souls?
Why Carbon Nanotubes Spell Trouble for Cells
|10:15:08 PM, Monday, September 19, 2011|
"It's been long known that asbestos spells trouble for human cells. Scientists have seen cells stabbed with spiky, long asbestos fibers, and the image is gory: Part of the fiber is protruding from the cell, like a quivering arrow that's found its mark.
But scientists had been unable to understand why cells would be interested in asbestos fibers and other materials at the nanoscale that are too long to be fully ingested. Now a group of researchers at Brown University explains what happens. Through molecular simulations and experiments, the team reports in Nature Nanotechnology that certain nanomaterials, such as carbon nanotubes, enter cells tip-first and almost always at a 90-degree angle. The orientation ends up fooling the cell; by taking in the rounded tip first, the cell mistakes the particle for a sphere, rather than a long cylinder. By the time the cell realizes the material is too long to be fully ingested, it's too late.
"It's as if we would eat a lollipop that's longer than us," said Huajian Gao, professor of engineering at Brown and the paper's corresponding author. "It would get stuck."
The research is important because nanomaterials like carbon nanotubes have promise in medicine, such as acting as vehicles to transport drugs to specific cells or to specific locations in the human body. If scientists can fully understand how nanomaterials interact with cells, then they can conceivably design products that help cells rather than harm them.
"If we can fully understand (nanomaterial-cell dynamics), we can make other tubes that can control how cells interact with nanomaterials and not be toxic," Gao said. "We ultimately want to stop the attraction between the nanotip and the cell."
Like asbestos fibers, commercially available carbon nanotubes and gold nanowires have rounded tips that often range from 10 to 100 nanometers in diameter. Size is important here; the diameter fits well within the cell's parameters for what it can handle. Brushing up against the nanotube, special proteins called receptors on the cell spring into action, clustering and bending the membrane wall to wrap the cell around the nanotube tip in a sequence that the authors call "tip recognition." As this occurs, the nanotube is tipped to a 90-degree angle, which reduces the amount of energy needed for the cell to engulf the particle..."
Gamers Succeed Where Scientists Fail: Molecular Structure of Retrovirus Enzyme Solved, Doors Open to New AIDS Drug Design
|11:51:16 PM, Sunday, September 18, 2011|
"Gamers have solved the structure of a retrovirus enzyme whose configuration had stumped scientists for more than a decade. The gamers achieved their discovery by playing Foldit, an online game that allows players to collaborate and compete in predicting the structure of protein molecules.
After scientists repeatedly failed to piece together the structure of a protein-cutting enzyme from an AIDS-like virus, they called in the Foldit players. The scientists challenged the gamers to produce an accurate model of the enzyme. They did it in only three weeks.
This class of enzymes, called retroviral proteases, has a critical role in how the AIDS virus matures and proliferates. Intensive research is under way to try to find anti-AIDS drugs that can block these enzymes, but efforts were hampered by not knowing exactly what the retroviral protease molecule looks like.
"We wanted to see if human intuition could succeed where automated methods had failed," said Dr. Firas Khatib of the University of Washington Department of Biochemistry. Khatib is a researcher in the protein structure lab of Dr. David Baker, professor of biochemistry.
Remarkably, the gamers generated models good enough for the researchers to refine and, within a few days, determine the enzyme's structure. Equally amazing, surfaces on the molecule stood out as likely targets for drugs to de-active the enzyme.
"These features provide exciting opportunities for the design of retroviral drugs, including AIDS drugs," wrote the authors of a paper appearing Sept. 18 in Nature Structural & Molecular Biology. The scientists and gamers are listed as co-authors.
This is the first instance that the researchers are aware of in which gamers solved a longstanding scientific problem.
Fold-it was created by computer scientists at the University of Washington Center for Game Science in collaboration with the Baker lab..."
This Beetle Uses Eggs as Shields Against Wasps
|11:34:18 PM, Sunday, September 18, 2011|
"New University of Arizona research has discovered that seed beetles from the desert Southwest shelter their broods from attacking parasitic wasps under a stack of dummy eggs.
They lead modest lives among the palo verde, mesquite and acacia trees throughout the Southwestern U.S., laying their eggs on seed pods and defending the survival of their offspring against the parasitic wasp species that attacks their eggs before their young can develop.
They are the seed beetles Mimosestes amicus, living all around us in the trees of Tucson, and yet remaining all but invisible to our eyes – or nearly so.
Now, doctoral candidate Joseph Deas in the University of Arizona's Graduate Interdisciplinary Program in Entomology and Insect Science, along with his faculty advisor Martha Hunter in the department of entomology, is peering into their world through his microscope and has discovered something novel: The beetles, whose eggs frequently are parasitized by the wasp Uscana semifumipennis, have a strategy to protect their offspring that goes beyond a helpful habit.
"They're stacking their eggs in order to protect them from these parasitic wasps," said Deas, whose research appears in the Proceedings of the Royal Society B on Sept. 14.
The eggs have eyes
The wasps, called parasitoids because they kill their host rather than just taking advantage of its resources, deposit their own eggs inside the beetles'. The wasp larva gets a head start in life and develops before the beetle larva, hijacking the beetle egg yolk for its own nourishment.
"You can tell when an egg has been parasitized because the egg will start to darken and blacken," said Deas. "The beetle larva by that time will never form because all of the yolk is going inside the wasp larva. And then you can see little red eyes in there; the beetles don't have red eyes. It looks very evil."
As often happens in science, Deas came upon the discovery of M. amicus' strategy through the course of a different investigation..."
Shake, Rattle and ... Power Up? A New MEMS Device Generates Energy From Small vibrations
|11:25:39 PM, Sunday, September 18, 2011|
"Prominent scientists, including Sir David Attenborough and Richard Dawkins, have called on the government to toughen its guidance on the promotion of creationism in classrooms, accusing "religious fundamentalists" of portraying it as scientific theory in publicly funded schools.
Today's wireless-sensor networks can do everything from supervising factory machinery to tracking environmental pollution to measuring the movement of buildings and bridges. Working together, distributed sensors can monitor activity along an oil pipeline or throughout a forest, keeping track of multiple variables at a time.
While uses for wireless sensors are seemingly endless, there is one limiting factor to the technology — power. Even though improvements have brought their energy consumption down, wireless sensors’ batteries still need changing periodically. Especially for networks in remote locales, replacing batteries in thousands of sensors is a staggering task.
To get around the power constraint, researchers are harnessing electricity from low-power sources in the environment, such as vibrations from swaying bridges, humming machinery and rumbling foot traffic. Such natural energy sources could do away with the need for batteries, powering wireless sensors indefinitely.
Now researchers at MIT have designed a device the size of a U.S. quarter that harvests energy from low-frequency vibrations, such as those that might be felt along a pipeline or bridge. The tiny energy harvester — known technically as a microelectromechanical system, or MEMS — picks up a wider range of vibrations than current designs, and is able to generate 100 times the power of devices of similar size. The team published its results in the Aug. 23 online edition of Applied Physics Letters.
“There are wireless sensors widely available, but there is no supportive power package,” says Sang-Gook Kim, a professor of mechanical engineering at MIT and co-author of the paper. “I think our vibrational-energy harvesters are a solution for that.”
Putting the squeeze on
To harvest electricity from environmental vibrations, researchers have typically looked to piezoelectric materials such as quartz and other crystals. Such materials naturally accumulate electric charge in response to mechanical stress (piezo, in Greek, means to squeeze or press). In the past few years, researchers have exploited piezoelectric material, or PZT, at the microscale, engineering MEMS devices that generate small amounts of power..."
Scientists Demand Tougher Guidelines on Teaching of Creationism in Schools
|10:15:30 PM, Sunday, September 18, 2011|
"Prominent scientists, including Sir David Attenborough and Richard Dawkins, have called on the government to toughen its guidance on the promotion of creationism in classrooms, accusing "religious fundamentalists" of portraying it as scientific theory in publicly funded schools.
A group of 30 scientists have signed a statement saying it is "unacceptable" to teach creationism and intelligent design, whether it happens in science lessons or not. The statement claims two organisations, Truth in Science and Creation Ministries International are "touring the UK and presenting themselves as scientists and their creationist views as science".
"Creationism and intelligent design are not scientific theories, but they are portrayed as scientific theories by some religious fundamentalists who attempt to have their views promoted in publicly funded schools," the scientists say.
"There should be enforceable statutory guidance that they may not be presented as scientific theories in any publicly funded school of whatever type."
The scientists claim organisations such as Truth in Science are encouraging teachers to incorporate intelligent design into their science teaching.
"Truth in Science has sent free resources to all secondary heads of science and to school librarians around the country that seek to undermine the theory of evolution and have intelligent design ideas portrayed as credible scientific viewpoints. Speakers from Creation Ministries International are touring the UK, presenting themselves as scientists and their creationist views as science at a number of schools."
Free schools and academies were not obliged to teach the national curriculum and so were "under no obligation to teach evolution at all," it added.
Truth in Science denied advocating the teaching of creationism in schools. "We wish to highlight the scientific weaknesses of neo-Darwinism and to encourage a more critical approach to the teaching of evolution in schools and universities," it said in a statement.
Creation Ministries International was unavailable for comment..."
Synthetic DNA Added to Yeast Cells, Paving Way for 'Evolution' on Demand
|9:03:47 PM, Sunday, September 18, 2011|
"Life forms have been created that carry strands of genetic material designed and built from scratch in the lab, paving the way for on-demand "evolution" of organisms.
Scientists made sections of chromosomes, the long molecules that bear DNA, and transferred them into yeast cells, of the kind normally used in baking.
The cells adopted the new genetic code as part of their normal cellular machinery and, to the scientists' surprise, appeared as healthy as their natural counterparts.
The feat is a big step towards the manufacture of completely synthetic organisms that could be designed to churn out biofuels, vaccines and industrial chemicals, said Jef Boeke, who led the study at Johns Hopkins University in Maryland.
Studies of bugs with synthetic DNA are widely anticipated to shed light on some of the toughest questions in biology, such as what is the minimal suite of genes required for life on Earth.
"We have created a research tool that not only lets us learn more about yeast biology, but also holds out the possibility of someday designing genomes for specific purposes, like making new vaccines or medications," said Jef Boeke, who led the study at Johns Hopkins University in Maryland.
Built into the synthetic chromosomes are genetic sequences that, when triggered by a chemical, dramatically rearrange the organism's genes. The technique, known as genome scrambling, allows scientists to accelerate the evolution of the organisms on demand, by creating thousands of new strains and collecting the best survivors.
The advance was made possible by powerful techniques that have emerged from rapid developments in genetics, computing and synthetic chemistry.
Boeke's work centred on a yeast known as Saccharomyces cerevisiae, one of the most well-understood organisms in the field of genetics. It has 16 chromosomes that together carry around 6000 genes..."
Dark Matter Packs a Punch: Milky Way's Spiral Arms Formed by Intergalactic Collision
|8:46:25 AM, Saturday, September 17, 2011|
"The signature spiral arms of the Milky Way galaxy were likely formed by an epic collision between the Milky Way and the Sagittarius Dwarf galaxy, according to a University of Pittsburgh researcher and his collaborators, published today in the prestigious British journal Nature.
Supercomputer simulations by Christopher W. Purcell, postdoctoral research associate in the Department of Physics and Astronomy in Pitt's School of Arts and Sciences, and colleagues report their findings in a paper titled "The Sagittarius Impact as an Architect of Spirality and Outer Rings in the Milky Way."
This paper is the first to identify Sagittarius as the architect of spiral structure in our Milky Way. "It presents a new and somewhat unexpected way of thinking about why the galaxy we live in looks the way it does," says Purcell.
"Cosmologically speaking, it demonstrates the idea that relatively small impacts like this can have a dramatic impact on the structure of galaxies throughout the universe," he adds. This idea had been assumed theoretically, but never demonstrated.
Purcell's collaborators include University of California High-Performance AstroComputing Center (UC-HIPACC)-affiliates James S. Bullock, Erik J. Tollerud, and Miguel Rocha, all at the University of California at Irvine. The fifth coauthor is Sukanya Chakrabarti at Florida Atlantic University.
In the field of cosmology, supercomputer simulations are the only laboratories for scientific experimentation. With supercomputers, astronomers can recreate a small-scale simulation or model of distant, violent events that occurred over billions of years, and observe that model in sped-up time, in order to make predictions that can be tested by actual observations of the universe..."
Synthetic Lint Ends Up In Oceans
|8:31:29 AM, Saturday, September 17, 2011|
"Every time a garment made from polyester or other synthetic fabric goes through the wash, it sheds tiny plastic fibers. Thousands of them. It turns out that these fibers end up fouling coastal environments throughout the globe, a global research team finds.
Itsy bitsy plastic pellets, such as those used for their abrasive qualities in products like skin cleansers and paint removers, also turn up in coastal sand, a separate study reports. Like polyester lint, these micropellets also go down the drain, through water treatment plants and into coastal waters.
The mass that microplastic bits contribute to marine pollution is small, concedes Mark Browne of University College Dublin, who led the fiber study. But that doesn’t mean their impact is benign, he adds.
Browne’s group sampled shoreline habitats at 18 sites on six continents. Plastic fibers polluted every one, with sites nearest urban centers hosting the most. At any site, microplastic fibers constituted more than 65 percent of the plastic pieces, by number (with the exception of sand-size pellets, which this study ignored).
Since earlier work had uncovered plastic fibers at land sites treated with sewage, the researchers sampled outflows from sewage-treatment plants. These waters also hosted acrylic and polyester fibers anywhere from 1 millimeter down to 10 micrometers in diameter.
This suggested that laundry might be a source. So over the next year, the researchers laundered individual garments and blankets in washing machines, running several empty cycles to clean out residual fibers between each wash. These tests “demonstrated that a single garment can produce greater than 1,900 fibres per wash,” the researchers report online September 6 in Environmental Science & Technology. Fleece fabrics shed the most.
What really makes microplastics potentially dangerous is the contaminants they ferry, argues Anthony Andrady of North Carolina State University in Raleigh, a materials scientist and polymers specialist not connected with the new study. “In the ocean, plastics act like a sponge,” he explains, absorbing and concentrating fat-soluble pollutants.
Indeed, in a study in the November 2010 Marine Pollution Bulletin, researchers in Portugal reported finding pollutant-tainted microplastic pellets..."
Strange Vent-Fellows: Chemosynthetic Shrimp, Tubeworms Together for First Time at Hydrothermal Vent
|8:12:40 AM, Saturday, September 17, 2011|
"Ocean explorers on NOAA Ship Okeanos Explorer observed two species of marine life scientists believe have never before been seen together at a hydrothermal vent -- chemosynthetic shrimp and tubeworms. They also observed the first known live tubeworms ever seen at a hydrothermal vent in Atlantic waters. The discoveries were made August 5-15 during an expedition to the Mid-Cayman Rise south of Grand Cayman Island in the Caribbean.
"On the very first ROV, or remotely-operated vehicle, dive, we observed abundant shrimp of a species different in appearance from other Mid-Atlantic Ridge species," said Professor Paul Tyler, Ph.D., a marine biologist from the University of Southampton in the United Kingdom who was aboard Okeanos Explorer. "These shrimp had characteristics previously seen only on shrimp containing chemosynthetic bacteria, and we identified them as such."
"During the ROV's second dive, we were witness to the first discovery of a live hydrothermal tubeworm in the Atlantic," said expedition Science Lead Chris German, Ph.D., chief scientist for the National Deep Submergence Facility at the Woods Hole Oceanographic Institution in Massachusetts. "I will take that home as my personal key discovery moment for the cruise."
The two discoveries blended into what German described as an even more remarkable discovery. "Not only did we see extensive tube worm communities of differing sizes and shapes across the length and breadth of a large hydrothermal vent field, but we observed for the first time anywhere, chemosynthetic shrimp and tubeworms inhabiting the same hydrothermal site," he said.
"The significance of these observations is that the iconic symbol of Pacific vents is the tubeworm, while the iconic symbol of Atlantic vents is the vent shrimp," added Tyler. "To find both together has important implications for the evolution of vent communities in the Caribbean as the Atlantic became separated from the Pacific some five million years ago."
Chemosynthetic tubeworms and shrimp are unlike most other life on Earth that are photosynthetic -- relying on energy from the sun. These new hydrothermal animals, by contrast, exist on the deep and dark ocean floor where no sunlight penetrates. They derive energy instead, from chemicals that rise in the hot water of hydrothermal vents making them chemosynthetic.
Tubeworms rising six feet from the seafloor were first discovered in 1977 next to hydrothermal vents in Pacific waters at the Galapagos near where the underwater tectonic plates spread. Since then, smaller tubeworms have been found at seafloor cold seeps in the Gulf of Mexico, but until this discovery, have not been observed at vents in the Atlantic..."
Bats Adjust Their 'Field-of-View'
|8:08:32 AM, Saturday, September 17, 2011|
"A new study reveals that the way fruit bats use biosonar to 'see' their surroundings is significantly more advanced than first thought. The study, published September 13 in the online, open access journal PLoS Biology, examines Egyptian fruit bats (Rousettus aegyptiacus), which use echolocation to orient inside their caves and to find fruit hidden in the branches of trees. Their high-frequency clicks form a sonar beam that spreads across a fan-shaped area, and the returning echoes allow them to locate and identify objects in that region. As these bats were considered to have little control over their vocalizations, scientists have puzzled over how they are able to navigate through complex environments.
The research team, led by Nachum Ulanovsky of the Weizmann Institute in Israel and Cynthia Moss of the University of Maryland, reports that these bats adapt to environmental complexity using two tactics. First, they alter the width of their sonar beam, similar to the way humans can adjust their spotlight of attention in order to spot, for example, a friend in a crowded room. Second, they modify the intensity of their emissions. "The work presented here reveals a new parameter under adaptive control in bat echolocation", says Ulanovsky.
Ulanovsky and his team trained five Egyptian fruit bats to locate and land on a mango-sized plastic sphere placed in various locations in a large, dark room equipped with an array of 20 microphones that recorded vocalizations. In one set of experiments, the researchers simulated an obstacle-filled forest by surrounding the sphere with two nets spread between four poles. To reach the target, the bats flew through a narrow corridor whose width and orientation varied from trial to trial.
In the obstacle-filled environment, the bats covered three times as much area with each pair of clicks as they did when the obstacles weren't there. The angle separating each two beams was also wider and the volume of the clicks louder, and these differences became more pronounced as they drew further into the corridor and therefore closer to their obstacles. This larger 'field of view' allowed the bats to track the sphere and the poles simultaneously, and avoid collisions while landing.
"This is the first report, in any sensory system, of an active increase in field-of-view in response to changes in environmental complexity," says Ulanovsky. Although these new findings may be unique to Egyptian fruit bats because of their rapid tongue movements, Ulanovsky explains that their results "suggest that active sensing of space by animals can be much more sophisticated than previously thought – and they call for a re-examination of current theories of spatial orientation and perception.""
Paris Ban on Muslim Street Prayers Comes Into Effect
|4:08:33 AM, Saturday, September 17, 2011|
"A ban on saying prayers in the street, a practice by French Muslims unable to find space in mosques, has come into effect in the capital, Paris.
Interior Minister Claude Gueant has offered believers the use of a disused fire brigade barracks instead.
The phenomenon of street prayers, which see Muslims spreading mats on footpaths, became a political issue after far right protests.
France is home to the biggest Muslim minority in Western Europe.
By some estimates, as many as six million French people, or just under 10% of the population, are Muslims, with origins in France's former North African colonies.
Their integration has been a source of political debate in recent years, and earlier this year France became the first EU state to ban the wearing of the Islamic veil in public.
The new ban came into force at midnight (22:00 GMT) on Thursday, in time for traditional Muslim Friday prayers.
Speaking earlier this week to Le Figaro, Mr Gueant said about 1,000 people were using two streets in the capital's multi-ethnic Goutte d'Or district for prayers.
He said an agreement had been reached with two local mosques for the state to rent out the disused barracks on Boulevard Ney with floorspace of 2,000 sq m (yds) for three years..."
Skull Points to a More Complex Human Evolution in Africa
|4:01:06 AM, Saturday, September 17, 2011|
"Scientists have collected more evidence to suggest that ancient and modern humans interbred in Africa.
Reanalysis of the 13,000-year-old skull from a cave in West Africa reveals a skull more primitive-looking than its age suggests.
The result suggests that the ancestors of early humans did not die out quickly in Africa, but instead lived alongside their descendents and bred with them until comparatively recently.
The results are published in PLoS ONE.
The skull, found in the Iwo Eleru cave in Nigeria in 1965, does not look like a modern human.
It is longer and flatter with a strong brow ridge; features closer to a much older skull from Tanzania, thought to be around 140,000 years old.
Prof Katerina Harvati from the University of Tuebingen in Germany used new digitising techniques to capture the surface of the skull in detail.
The new technique improved upon the original measurements done with callipers by letting researchers see subtler details about the skull's surface.
"[The skull] has got a much more primitive appearance, even though it is only 13,000 years old," said Chris Stringer, from London's Natural History Museum, who was part of the team of researchers.
"This suggests that human evolution in Africa was more complex... the transition to modern humans was not a straight transition and then a cut off."
Prof Stringer thinks that ancient humans did not die away once they had given rise to modern humans..."
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