Hens Evolve Secret Sex Strategy
|12:02:54 AM, Thursday, September 08, 2011|
"Scientists have discovered that female chickens have a remarkable ability to choose the father of their eggs.
Wily hens have evolved the ability to eject the sperm of unsuitable mates say researchers working with Swedish birds.
Promiscuous roosters try to ensure that their genes are passed on by mating with as many females as possible.
But by removing the genetic material of males they consider socially inferior, the hens have managed to retain control of paternity.
Many species ranging from zebras to insects use the strategy of sperm ejection - but the evolutionary ideas behind it are often uncertain.
Among birds, male Dunnocks force females to eject the sperm of other suitors in order to protect their own genes.
But this research indicates that among chickens the battle of the sexes seems to be all about female empowerment.
Working with feral fowl in Sweden, the scientists found that many matings were forced, as the roosters are twice the size of the hens.
To cope with the unwanted attention, females have evolved the ability to remove the ejaculate of those males they consider undesirable.
Dr Rebecca Dean from Oxford University carried out the study. She said: "It's really important for females to have the best male sperm to fertilise her eggs so if she can't choose before copulation then having a mechanism to choose after copulation could really increase her evolutionary fitness."
Even when unforced, the females still exercised their right to choose by opting to eject the sperm of males they considered to be at the bottom of the pecking order..."
Self-Retracting Needle Could End Botched Injections
|11:51:50 PM, Wednesday, September 07, 2011|
"Up to a third of the 25 million intravenous injections carried out in Britain each year fail first time, often because doctors and nurses push the needle straight through the vein without noticing, researchers said.
But the problem could be solved by a newly designed syringe which automatically detects when it enters a vein and prevents the needle from travelling any further.
Upon passing through the wall of a vein, the change in pressure activates a spring which forces the needle to instantly withdraw itself.
The needle is housed within a plastic tube, which remains in the vein and allows the drug inside the syringe to enter the blood stream.
Researchers from Nottingham Trent University, who designed the system, and Olberon medical Innovations, the medical equipment manufacturer, said the self-retracting needle could be produced for the same price as traditional needles..."
Endangered Horse Has Ancient Origins and High Genetic Diversity, New Study Finds
|10:32:21 PM, Wednesday, September 07, 2011|
"An endangered species of horse -- known as Przewalski's horse -- is much more distantly related to the domestic horse than researchers had previously hypothesized, reports a team of investigators led by Kateryna Makova, a Penn State University associate professor of biology. The scientists tested the portion of the genome passed exclusively from mother to offspring -- the mitochondrial DNA -- of four Przewalski's horse lineages and compared the data to DNA from the domestic horse (Equus caballus). They concluded that, although previous scientists had assumed that Przewalski's horse and the domestic horse had diverged around the time that horses were domesticated -- about 6,000 to 10,000 years ago -- the real time of the two species' divergence from one another is much more ancient. The data gleaned from the study also suggest that present-day Przewalski's horses have a much more diverse gene pool than previously hypothesized. The new study's findings could be used to inform conservation efforts to save the endangered horse species, of which only 2,000 individuals remain in parts of China and Mongolia, and in wildlife reserves in California and the Ukraine. The paper will be published in the journal Genome Biology and Evolution.
Przewalski's horse -- a stocky, short-maned species named after a Russian explorer who first encountered the animal in the wild -- became endangered during the middle of the last century when the species experienced a population bottleneck -- an evolutionary event in which many or most members of a population or a species die. "Sadly, this bottleneck was the result of human activity," Makova explained. "Przewalski's horses were hunted down for food, and their natural habitat, the steppes, were converted into farm land so the horses basically had nowhere to live and breed. By the late 1950s, only 12 individual horses remained." Makova said that because conservationists have made noble efforts to rescue this dwindling population, the present-day population has grown to 2,000.
In a study that had never been attempted by previous scientists, Makova and her team analyzed the complete mitochondrial genomes from four female lineages that currently survive within the Przewalski's horse population. They first determined that the mitochondrial genomes of two of the maternal lineages actually were identical, thus narrowing the genetic pool to three maternal lineages. Then, they tested their data against the prevailing hypotheses about the genetic history of Przewalski's horse. According to one hypothesis, Przewalski's horse evolved first, with the domestic horse later evolving as a derivative species. According to another hypothesis, the genetic story is the opposite: the direct ancestors of the domestic horse were first on the evolutionary scene, with Przewalski's horse evolving and forming a new species later. According to the former hypothesis, the divergence of the two species had to have occurred around the time of horse domestication -- about 6,000 to 10,000 years ago..."
Earthly Riches Heaven Sent: Meteorites May Have Peppered Earth With Precious Metals
|10:14:05 PM, Wednesday, September 07, 2011|
"A meteorite maelstrom that pummeled Earth and pocked the moon with craters billions of years ago may have had a silver lining — and linings made of other metals, too.
New evidence from old rocks suggests that many of the precious metals mined today were delivered to the planet by a bombardment of stony meteorites called chondrites that lasted for hundreds of millions of years.
“Adding a tiny amount of chondritic material could explain where many present-day metals came from,” says Matthias Willbold, a geochemist at the University of Bristol in England whose team reports the new findings in the Sept. 8 Nature.
The abundance of heavy metals near Earth’s surface has long puzzled scientists. Within 50 million years of the planet’s formation, much of its iron sank to the middle to form the core. Silver, platinum and some other precious metals followed, according to laboratory experiments that recreate this partitioning. These elements moved beyond the reach of human tools, leaving the mantle outside the core barren.
Searching for a source that could have later replenished these metals, Willbold and colleagues turned to some of the oldest known rocks on the planet’s surface. The 3.8-billion-year-old Isua greenstone belt, found in West Greenland, probably formed from melted bits of mantle that date to just after the creation of the Earth’s core but before the massive influx of meteorites that geologists call the late heavy bombardment.
The researchers focused on different forms, known as isotopes, of the metal tungsten in the rocks. When the core formed, it swallowed up most of this metal. But a short-lived element called hafnium left behind in the mantle quickly broke down into a lighter isotope, tungsten-182..."
1/8th Scale Nissan GT-R Model by UK Model Car Maker Amalgam
|11:08:51 PM, Tuesday, September 06, 2011|
"...Amalgam are recognized as the premiere model maker and supplier of models to high end luxury car manufacturers and racing teams globally.
At 1/8th scale this model is around 22 inches or 58 cm in length and weighs 5kg. It’s huge by any standard and is the most phenomenally well detailed model you’ll ever see.
Take a look at these photos (and the others at the link below). You can see everything has been recreated from the texture of the brake rotors, the reflections in the tail lamps, the stitching on the seats and accurate labels on the dashboard buttons.
These models are now available via Zele International in Japan for 398,000 yen a piece. For those wanting a model of their own GT-R, a custom version of the Amalgam GT-R model is available and starts at a price of 498,000 yen."
-- Wow! This looks just like a real Nissan GT-R, but it seems it comes with a price tag to match such fantastic replica at $5000+ haha... Follow the "See Here" link for more photos.
Revolution by Bill Newsinger
|11:00:02 PM, Tuesday, September 06, 2011|
Tech Company to Build Science Ghost Town in NM
|10:55:14 PM, Tuesday, September 06, 2011|
"New Mexico, home to several of the nation's premier scientific, nuclear and military institutions, is planning to take part in an unprecedented science project — a 20-square-mile (50-square-kilometer) model of a small U.S. city.
A Washington, D.C.-based technology company announced plans Tuesday to build the state's newest ghost town to test everything from renewable energy innovations to intelligent traffic systems, next-generation wireless networks and smart-grid cyber security systems.
Although no one will live there, the replica city will be modeled after a typical American town of 35,000 people, complete with highways, houses and commercial buildings, old and new.
Pegasus Global Holdings chief executive officer, Bob Brumley, says the $200 million project, known as The Center, will be a first of its kind in the U.S., creating a place for scientists at the state's universities, federal labs and military installations to test their innovations for upgrading cities to 21st century, green technology and infrastructure in a real world setting.
It will also enable them to rub shoulders with investors, meaning it could ultimately draw enough new businesses to give the state a technology corridor like that in California's Silicon Valley or Virginia's Reston, Brumley said.
"The idea for The Center was born out of our own company's challenges in trying to test new and emerging technologies beyond the confines of a sterile lab environment," said Brumley. "The Center will allow private companies, not for profits, educational institutions and government agencies to test in a unique facility with real world infrastructure, allowing them to better understand the cost and potential limitations of new technologies prior to introduction."
For instance, he said, developers of solar technology would be able to assess exactly how their systems would be delivered and used in one house where the thermostat is set at 78, and another where it's set at 68. The center could also help show how efficient it might be in an old building versus a new one..."
Our Galaxy Might Hold Thousands of Ticking 'Time Bombs'
|10:47:59 PM, Tuesday, September 06, 2011|
"In the Hollywood blockbuster "Speed," a bomb on a bus is rigged to blow up if the bus slows down below 50 miles per hour. The premise - slow down and you explode - makes for a great action movie plot, and also happens to have a cosmic equivalent.
New research shows that some old stars might be held up by their rapid spins, and when they slow down, they explode as supernovae. Thousands of these "time bombs" could be scattered throughout our Galaxy.
"We haven't found one of these 'time bomb' stars yet in the Milky Way, but this research suggests that we've been looking for the wrong signs. Our work points to a new way of searching for supernova precursors," said astrophysicist Rosanne Di Stefano of the Harvard-Smithsonian Center for Astrophysics (CfA).
The specific type of stellar explosion Di Stefano and her colleagues studied is called a Type Ia supernova. It occurs when an old, compact star known as a white dwarf destabilizes.
A white dwarf is a stellar remnant that has ceased nuclear fusion. It typically can weigh up to 1.4 times as much as our Sun - a figure called the Chandrasekhar mass after the astronomer who first calculated it. Any heavier, and gravity overwhelms the forces supporting the white dwarf, compacting it and igniting runaway nuclear fusion that blows the star apart.
There are two possible ways for a white dwarf to exceed the Chandrasekhar mass and explode as a Type Ia supernova. It can accrete gas from a donor star, or two white dwarfs can collide. Most astronomers favor the first scenario as the more likely explanation. But we would expect to see certain signs if the theory is correct, and we don't for most Type Ia supernovae..."
It Wasn't Just Neanderthals: Ancient Humans Had Sex with Other Hominids
|10:28:01 PM, Tuesday, September 06, 2011|
"Scientists have collected evidence for years that modern humans interbred with our ridge-browed Neanderthal ancestors in Eurasia. But in Africa, where the homo sapien species is said to have emerged, a lack of genetic evidence has left researchers scratching their heads about exactly how we came to beat out not only the Neanderthals, or homo neanderthalis, but other archaic species like homo erectus and homo habilus. A new paper published by Michael Hammer from the University of Arizona, however, provides evidence that homo sapiens not only interbred with Neanderthals in Eurasia, they also had sex with several species of our ancestors across the African continent. And they did it often. "We think there were probably thousands of interbreeding events," said Hammer. "It happened relatively extensively and regularly."
What we know about the history of our species has long been determined by what we can learn from our ancestors' remains. As recently as five years ago, researchers deduced that humans and Neanderthals had interbred at some point based on the shapes of skulls found in caves or buried under thousands of years worth of soil. A ground-breaking paper published last year by Swedish evolutionary biologist Svante Pääbo in Science brought genetics into the equation. Pääbo provided genetic proof that homo sapiens migrated out of Africa and into the Neanderthal-occupied Eurasian continent, where they met and mated with the more primitive men. Pääbo and his team made the discovery while comparing samples of Neanderthal DNA with that of modern human DNA. In a recent profile on Pääbo, The New Yorker's Elizabeth Kolbert describes what's become known as the "leaky replacement" hypothesis:
Before modern humans "replaced" the Neanderthals, they had sex with them. The liaisons produced chil- dren, who helped to people Europe, Asia, and the New World.
The leaky-replacement hypothesis--assuming for the moment that it is correct--provides further evidence of the closeness of Neanderthals to modern humans. Not only did the two interbreed; the resulting hybrid offspring were functional enough to be integrated into human society. Some of these hybrids survived to have kids of their own, who, in turn, had kids, and so on to the present day. Even now, at least thirty thousand years after the fact, the signal is discernible: all non-Africans, from the New Guineans to the French to the Han Chinese, carry somewhere between one and four per cent Neanderthal DNA..."
Flaring Up - Surfing with a Flare
|4:40:55 PM, Sunday, September 04, 2011|
Researchers Discover Gene Defect That Predisposes People To Leukemia
|2:25:29 PM, Sunday, September 04, 2011|
"A new genetic defect that predisposes people to acute myeloid leukemia and myelodysplasia has been discovered. The mutations were found in the GATA2 gene. Among its several regulatory roles, the gene acts as a master control during the transition of primitive blood-forming cells into white blood cells.
The researchers started by studying four unrelated families who, over generations, have had several relatives with acute myeloid leukemia, a type of blood cancer. Their disease onset occurred from the teens to the early 40s. The course was rapid.
The findings will be reported Sept. 4 in Nature Genetics. The results come from an international collaboration of scientists and the participation of families from Australia, Canada, and the United States.
In collaboration with Dr. Hamish Scott and Dr. Richard J. D'Andrea at the Centre for Cancer Biology, University of Australia, Adelaide, the U.S. portion of the study was conducted by Dr. Marshall Horwitz, University of Washington (UW) professor of pathology. Horwitz practices genetic medicine at UW Medical Center and the UW Center for Human Development and Disability, both in Seattle.
The genetic mutation was first discovered in a patient from central Washington. The research participant had been successfully treated for leukemia in 1992 through a bone marrow transplant at UW Medical Center. At that time, Horwitz decided to seek a possible genetic reason after learning his patient had several family members with myelodysplastic syndrome, myeloid leukemia, and intractable mycobacteria infections..."
Scientists Produce First Stem Cells From Endangered Species
|2:14:08 PM, Sunday, September 04, 2011|
"Starting with normal skin cells, scientists from The Scripps Research Institute have produced the first stem cells from endangered species. Such cells could eventually make it possible to improve reproduction and genetic diversity for some species, possibly saving them from extinction, or to bolster the health of endangered animals in captivity.
A description of the accomplishment appeared in an advance online edition of the journal Nature Methods on September 4, 2011.
About five years ago, Oliver Ryder, PhD, the director of genetics at the San Diego Zoo Institute for Conservation Research, contacted Jeanne Loring, PhD, professor of developmental neurobiology at Scripps Research, to discuss the possibility of collecting stem cells from endangered species. Ryder's team had already established the Frozen Zoo, a bank of skin cells and other materials from more than 800 species and wondered if the thousands of samples they had amassed might be used as starting points.
Just as is hoped with humans, Ryder thought stem cells from endangered species might enable lifesaving medical therapies or offer the potential to preserve or expand genetic diversity by offering new reproduction possibilities.
At the time, although researchers were working with stem cells from embryos, scientists had not yet developed techniques for reliably inducing normal adult cells to become stem cells. But the technology arrived soon after, and scientists now accomplish this feat, called induced pluripotency, by inserting genes in normal cells that spark the transformation..."
Hubble Movies Reveal Solar-System-Sized Traffic Jams: Giant Jets Spewing from Newborn Stars Revealed in Telescope's Images
|10:19:54 PM, Saturday, September 03, 2011|
"When it comes to big-budget action movies, Rice University astronomer Patrick Hartigan prefers Hubble to Hollywood.
Using Hubble Space Telescope images collected over 14 years, Hartigan has created time-lapse movies that offer astronomers their first glimpse of the dynamic behavior of stellar jets, huge torrents of gas and particles that spew from the poles of newborn stars.
An analysis of the movies that was published in The Astrophysical Journal is forcing astronomers to rethink some of the processes that occur during the latter stages of star birth. And in an effort to learn even more, Hartigan and colleagues are using powerful lasers to recreate a small-scale version of the solar-system-sized jets in a lab in upstate New York.
"The Hubble's given us spectacular images," said Hartigan, professor of physics and astronomy at Rice. "In the nebulae where stars are born, for instance, we can see beautiful filaments and detailed structure. We know these images are frozen snapshots in time, but we would need to watch for hundreds of thousands of years to see how things actually play out."
Hartigan said stellar jets are different because they move very quickly. Stellar jets blast out into space from the poles of newly formed stars at about 600,000 miles an hour. Astronomers first noticed them about 50 years ago, and they believe the sun probably had stellar jets when it formed about 4.5 billion years ago..."
Recycling Billboards into Modern Residential Buildings
|1:25:57 AM, Saturday, September 03, 2011|
"As more and more advertising goes online and transportation conservation becomes an increasing economic and ecological concern, what is the future fate of the infamous billboard? One proposal by Front Architects suggests turning these into lofted homes – small houses to be sure, but located in some potentially fascinating places.
Some of these unusually thin homes could be built in place from scratch, others could be transported to new locations or even left where they are in the urban environment.
Alas, the above image is only a computer-generated overlay in a real situation. Still, what would it be like to live in somewhere so public yet also removed from the street level? Somewhere surrounded by four walls and lifted up from the ground but at the same time exposed on all sides? Somewhere so strange but central?"
Alien Life More Likely on 'Dune' Planets, Study Suggests
|1:21:27 AM, Saturday, September 03, 2011|
"Desert planets like the one depicted in the science fiction classic "Dune" might be the most common type of habitable planet in the galaxy, rather than watery worlds such as Earth, a new study suggests.
And that's not the only surprising result.
The study also hints that scorching-hot Venus, where surface temperatures average 860 degrees Fahrenheit (460 degrees Celsius), might have been a habitable desert world as recently as 1 billion years ago.
Follow the water?
Nearly everywhere there is water on Earth, there is life. The search for life elsewhere in the universe has been guided by this fact, largely focusing on "aqua planets" with a lot of liquid water on their surfaces.
These worlds could be terrestrial planets largely covered with oceans, such as Earth, or theoretical "ocean planets" completely covered by a layer of water hundreds of miles deep, somewhat like thawed versions of Jupiter's icy moon Ganymede.
To be habitable, aqua planets must orbit their stars in a so-called "Goldilocks zone" where they are neither too hot nor too cold. If they are too far from the sun, they freeze. If they are too close, steam builds up in their atmospheres, trapping heat that vaporizes still more water, leading to a runaway greenhouse effect that boils all the oceans off the planet, as apparently happened on Venus.
Eventually, such planets get so hot, they force water vapor high enough into the atmosphere that it gets split into hydrogen and oxygen by ultraviolet light. The hydrogen then escapes into space, the oxygen likely reacts with the molten surface and gets incorporated into the mantle, and the planet's atmosphere loses all its water over time.
Instead of aqua planets with abundant water on their surfaces, researchers investigated what "land planets" might be like, ones with no oceans and vast dry deserts, but perhaps oases here and there. The planet Arrakis depicted in the science fiction classic "Dune" is one exceptionally well-developed example of a habitable land planet, said planetologist Kevin Zahnle at NASA's Ames Research Center in Mountain View, Calif..."
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