November 27, 2009
November 25, 2009
LHC Restarts operations at CERN
8:28 AM
Antoine
With just one bunch of particles circulating in each direction, the beams can be made to cross in up to two places in the ring.
From early in the afternoon, the beams were made to cross at points 1 and 5, home to the ATLAS and CMS detectors, both of which were on the look out for collisions.
Later, beams crossed at points 2 and 8, ALICE and LHCb.
“It’s a great achievement to have come this far in so short a time,” said CERN1Director General Rolf Heuer. “But we need to keep a sense of perspective – there’s still much to do before we can start the LHC physics programme.”
Beams were first tuned to produce collisions in the ATLAS detector, which recorded its first candidate for collisions at 14:22 this afternoon. Later, the beams were optimised for CMS. In the evening, ALICE had the first optimization, followed by LHCb.
Full story here
November 17, 2009
The Oracle at Delphi - Not Just Hot Air
9:51 AM
Beena
Most people are acquainted with the myths of ancient Greece. We've heard of Hercules and Zeus, Aphrodite and Era, Achilles and possibly Ulysses. But what about the oracle of Delphi? This was a mystic place where the gods, who knew everything and saw everything, communicated with the wretched humans and revealed to them the path to glory.
Unlike the mythical heroes, however, this place really existed, and now new scientific research has demonstrated how the legend began - and it's all thanks to the peculiar geological setting of the area – a combination of active faults, seismic activity and a layer of coal! Indeed it seems that two thousands years of wars and battles may have have been won or lost thanks to the advice of women whose senses were dulled by methane blowing from a crack in the ground!
Full Story Here
Self-Renewal of Specialized Cells
9:31 AM
Beena
Is the indefinite expansion of adult cells possible without recourse to stem cell intermediates?
The team led by Michael Sieweke at the Centre d'immunologie de Marseille Luminy (Université Aix-Marseille 2 / CNRS / INSERM) has shown that this is the case by achieving the ex vivo regeneration of macrophages, specialized cells in the immune system, over several months.
Published in Science on November 6, 2009, this discovery could be applied to other cell types. This research enables a clearer understanding of the mechanisms underlying cell differentiation, but above all raises many hopes for potential therapeutic applications.
The regenerative medicine of the future will be based on replacing damaged cells and repairing deficient organs, notably through the use of stem cells. Indeed, these cells are able not only to proliferate indefinitely but, in theory, to supply all types of cells to the human body.
However, the processes that allow the passage from adult (rather than embryonic) cells to stem cells ("reprogramming") are complex and full of risk, as are the processes necessary for the "retransformation" of stem cells into adult cells. The question then arises: might it not be more simple to generate the cells required without passing through the stem cell stage?
Whole Story Here
Are Earth's Oceans Made Of Extraterrestrial Material?
9:21 AM
Beena
Contrary to preconceived notions, the atmosphere and the oceans were perhaps not formed from vapors emitted during intense volcanism at the dawning of our planet.
Francis Albarède of the Laboratoire des Sciences de la Terre (CNRS / ENS Lyon / Université Claude Bernard) suggests that water was not part of the Earth's initial inventory but stems from the turbulence caused in the outer Solar System by giant planets.
Ice-covered asteroids thus reached the Earth around one hundred million years after the birth of the planets.
The Earth's water could therefore be extraterrestrial, have arrived late in its accretion history, and its presence could have facilitated plate tectonics even before life appeared.
The conclusions of the study carried out by Albarède feature in an article published on the 29 October 2009 in the journal Nature.
Space agencies have got the message: wherever there is life there has to be water. Around 4.5 billion years ago, the Earth was bequeathed with sufficient water for oceans to form and for life to find favorable niches in the seas and on the continents resulting from plate tectonics. In comparison, the Moon and Mercury are dry, mortally cold deserts, Mars dried up very quickly and the surface of Venus is a burning inferno.
According to books, the ocean and the atmosphere were formed from volcanic gases and the Earth's interior is the source of volatile elements. However, the rocks of the Earth's mantle are deficient in water (geochemists estimate its concentration at two hundredth percent). The same is true on Earth's sister planets, Venus and Mars.
The main reason proposed by Albarède is that, during the formation of the Solar System, the temperature never dropped sufficiently between the Sun and the orbit of Jupiter for volatile elements to be able to condense with planetary material. The arrival of water on Earth therefore corresponds to a late episode of planetary accretion.
Full Story Here
November 14, 2009
Australian scientists to start 'breast regrowth' trial
10:08 AM
Beena
It is hoped that if successful, the experimental stem cell breast-growing technique - called Neopec - could replace breast reconstructions and implants within three years.
Dr Phillip Marzella from the Bernard O'Brien Institute of Microsurgery in Melbourne, said a prototype trial of five to six women would start in the next three to six months "to demonstrate that the body can regrow its own fat supply in the breast".
"What we are hoping to do in the next two years is develop a biodegradable chamber so that the fat can grow inside the chamber and then the chamber will vanish naturally," Dr Marzella said.
"Nature abhors a vacuum, so the chamber itself, because it is empty, it tends to be filled in by the body."
Dr Marzella said the new breasts would feel normal to the patient.
Whole Story Here
LCROSS Impact Data Indicates Water on Moon
5:37 AM
Antoine
Secrets the moon has been holding, for perhaps billions of years, are now being revealed to the delight of scientists and space enthusiasts alike.
NASA today opened a new chapter in our understanding of the moon. Preliminary data from the Lunar CRater Observation and Sensing Satellite, or LCROSS, indicates that the mission successfully uncovered water during the Oct. 9, 2009 impacts into the permanently shadowed region of Cabeus cater near the moon’s south pole.
The impact created by the LCROSS Centaur upper stage rocket created a two-part plume of material from the bottom of the crater. The first part was a high angle plume of vapor and fine dust and the second a lower angle ejecta curtain of heavier material. This material has not seen sunlight in billions of years.
"We're unlocking the mysteries of our nearest neighbor and by extension the solar system. It turns out the moon harbors many secrets, and LCROSS has added a new layer to our understanding," said Michael Wargo, chief lunar scientist at NASA Headquarters in Washington.
Scientists have long speculated about the source of vast quantities of hydrogen that have been observed at the lunar poles. The LCROSS findings are shedding new light on the question of water, which could be more widespread and in greater quantity than previously suspected.
Full story here
November 10, 2009
How can someone die from drinking too much water?
8:42 PM
Beena
In January 2007, hours after competing in a radio station contest to win a Nintendo Wii, 28-year-old Jennifer Strange was found dead in her California home. The station's "Hold Your Wee for a Wii" challenge awarded the game system to the contestant who could drink the most water without having to take a trip to the bathroom. According to preliminary autopsy reports, Ms. Strange apparently died from drinking too much water too quickly, resulting in a condition called water intoxication.
At its most basic, water intoxication occurs when a person drinks so much water that the other nutrients in the body become diluted to the point that they can no longer do their jobs. You've probably heard the term electrolyte before, whether in reference to sports drinks (which provide electrolytes in addition to fluids) or to certain conditions, such as bulimia or diarrhea, that cause dangerous "electrolyte imbalances" in the body. Electrolytes are simply salt ions (atoms with an overall positive or negative charge) that cells use to move fluids and nerve messages into and out of cells and throughout the body. Without electrolytes, the body can't function (see What are electrolytes? for a more detailed description). Water intoxication causes an electrolyte imbalance that affects concentrations of the ion sodium, and it leads to a condition called hyponatremia.
In cases of water intoxication, it is extreme hyponatremia that can ultimately cause coma and death. If it's caught early, treatment with IV fluids containing electrolytes can lead to a complete recovery; but untreated, hyponatremia is fatal. Water intoxication is basically one form of hyponatremia -- the condition can also be caused by excessive sweating, severe burns, prolonged dehydration and certain liver and kidney problems, among other diseases and conditions.
When a person dies from hyponatremia as a result of water intoxication, the initiating factor is a severe sodium imbalance that causes massive cell damage. Sodium is a positively charged ion, and its role in the body is to circulate the fluids outside of cells. As a result, sodium helps regulate blood pressure and maintain the signals that let muscles operate properly, among other things. Cells actively maintain a precise sodium concentration in the body. Inside the cell, there are more electrolytes; outside the cell, there is more water. Cells keep sodium levels healthy by moving water and electrolytes into and out of the cell to either dilute or increase sodium levels in body fluids. But when someone drinks a tremendous amount of water in a short period of time, and the water does not contain any added electrolytes, the cellular maintenance system can't handle the level of sodium dilution that occurs.
The result is that cells desperately try to increase the sodium concentration in body fluids by taking in tremendous amounts of water. Some cells can swell a great deal; others cannot. Brain cells are constrained by the skull and can end up bursting with the pressure of the water they are taking in.
The exact amount of water intake that can lead to water intoxication is unknown and varies with each individual. Symptoms of water intoxication actually look a lot like the symptoms of alcohol intoxication, including nausea, altered mental state, and vomiting. Other symptoms include headaches, muscle weakness and convulsions. In severe cases of water intoxication, coma and death come fairly quickly as a result of brain swelling. The condition is quite rare in the general population, but in distance athletics, it's a known risk and is often avoided by drinking sports drinks instead of water during training and events.
Curvy women may be a clever bet
8:27 PM
Beena
Women with curvy figures are likely to be brighter than waif-like counterparts and may well produce more intelligent offspring, a US study suggests.
Researchers studied 16,000 women and girls and found the more voluptuous performed better on cognitive tests - as did their children.
The bigger the difference between a woman's waist and hips the better.
Researchers writing in Evolution and Human Behaviour speculated this was to do with fatty acids found on the hips.
In this area, the fat is likely to be the much touted Omega-3, which could improve the woman's own mental abilities as well as those of her child during pregnancy.
Men respond to the double enticement of both an intelligent partner and an intelligent child, the researchers at the Universities of Pittsburgh and California said.
The findings appear to be borne out in the educational attainments of at least one of the UK's most famous curvaceous women, Nigella Lawson, who graduated from Oxford.
Source
November 7, 2009
Even Babies Have "Accents," Crying Study Finds
5:59 PM
Beena
Newborn babies start learning language in the womb—and are born with what you might call accents, a new study of crying babies says.That fetuses hear and become accustomed to language is nothing new. Several studies have shown that, when exposed to different languages shortly after birth, a baby will typically indicate a preference for the language closest to the one he or she would've heard during gestation.
But recognizing a language and being able to speak it—or cry it—are two different things.Listening to Babies Cry—By ChoiceFor the new study, a team led by Kathleen Wermke at the Center for Prespeech Development and Developmental Disorders at Würzburg University in Germany studied the cry "melodies" of 60 healthy newborns—30 French and 30 German.The melodies, or intonations, aren't true accents, Wermke cautions—accents have to do with the ways words are pronounced.
The researchers knew that French speakers typically raise their pitch at the ends of words and phrases, while German speakers typically do the opposite.(Related: "Bilingual Babies Get Head Start—Before They Can Talk.")They also knew that melody—or in the case of spoken language, intonation—plays a crucial role in language learning. "This ultimately gave us the idea to look for specific melodic properties in newborns' crying," Wermke said.Intonations Give Babies AwayThe melodies of the newborn babies' cries followed the same intonations of the languages the babies had heard in the womb.
The French babies' cries, for example, tended to end on a rising note."Clearly, the long process of language learning begins with the perception and production of melody by human fetuses and infants," Wermke said.
The discovery may yield more than just an understanding of how language develops."Further analysis of human infants' crying and other utterances," she said, "may contribute to resolving the enigma as to how language may have emerged in early [human ancestors]."
But recognizing a language and being able to speak it—or cry it—are two different things.Listening to Babies Cry—By ChoiceFor the new study, a team led by Kathleen Wermke at the Center for Prespeech Development and Developmental Disorders at Würzburg University in Germany studied the cry "melodies" of 60 healthy newborns—30 French and 30 German.The melodies, or intonations, aren't true accents, Wermke cautions—accents have to do with the ways words are pronounced.
The researchers knew that French speakers typically raise their pitch at the ends of words and phrases, while German speakers typically do the opposite.(Related: "Bilingual Babies Get Head Start—Before They Can Talk.")They also knew that melody—or in the case of spoken language, intonation—plays a crucial role in language learning. "This ultimately gave us the idea to look for specific melodic properties in newborns' crying," Wermke said.Intonations Give Babies AwayThe melodies of the newborn babies' cries followed the same intonations of the languages the babies had heard in the womb.
The French babies' cries, for example, tended to end on a rising note."Clearly, the long process of language learning begins with the perception and production of melody by human fetuses and infants," Wermke said.
The discovery may yield more than just an understanding of how language develops."Further analysis of human infants' crying and other utterances," she said, "may contribute to resolving the enigma as to how language may have emerged in early [human ancestors]."
From a Distant Comet, a Clue to Life
2:52 PM
Beena
For the first time, a building block of proteins — and hence of life as we know it — has been found in a comet.
That adds to the prevailing notion that many of the ingredients for the origin of life showered down on the early Earth when asteroids (interplanetary rocks orbiting the inner solar system) and comets (dirty ice balls that generally congregate in the outer solar system beyond Neptune) made impact with the planet.
In the new research, scientists at the Goddard Space Flight Center, in Greenbelt, Md., detected the amino acid glycine in comet bits brought back in 2006 by the NASA space probe Stardust.
“It tells us more about the inventory of organics in the early solar system,” said Jamie Elsila, an astrochemist at Goddard who led the research.
Amino acids are small molecules that, when strung together into chains, form a diversity of proteins. For four decades, scientists have found a multitude of amino acids in some meteorites, the bits of asteroids that land on Earth. More recently, astronomers reported that amino acids might float throughout the cosmos, a belief resulting from their detection of the color signatures of glycine, the simplest of the amino acids, in distant interstellar gas clouds.
Some doubts remain about that claim, but if it is true, it would then not be surprising that when the clouds condense into stars and planets, the building blocks of life might be readily available there.
As for our solar system, meteorite data show that amino acids are present in its inner neighborhood, where asteroids orbit, but until now nothing has been known for certain about what might have formed farther out, where comets gather.
But on Jan. 2, 2004, the Stardust spacecraft flew through the tail of dust and gas of the comet Wild 2 (pronounced vilt two). Two years later, the probe returned to Earth, sending collected samples to the ground by parachute for scientists to analyze. Comets are thought to preserve material of the early solar system, largely unchanged for the last 4.5 billion years.
Within a few months, the Goddard scientists found glycine embedded in aluminum foil of the collecting apparatus. They had spent the time since then confirming that the glycine indeed came from the comet and not from contamination.
“It’s not necessarily particularly surprising,” Dr. Elsila said of her extraterrestrial glycine in a phone conversation Tuesday. “I would have been surprised if it wasn’t there.”
Dr. Elsila and her colleagues were able to show that the glycine from the comet had heavier quantities of the isotope carbon 13 than what occurs on Earth. They also detected a second amino acid, beta-alanine, but the quantities were too minuscule to confirm.
The findings were presented Sunday at a Washington meeting of the American Chemical Society and will be published in the journal Meteoritics & Planetary Science.
Donald E. Brownlee, a professor of astronomy at the University of Washington and principal investigator of the Stardust mission, said the discovery indicated that the chemical reactions that produce glycine, and presumably other amino acids, occurred throughout the early solar system.
“That means production of amino acids is fairly common,” Dr. Brownlee said.
That had not been a foregone conclusion, he said. Some scientists had suggested that the chemical reactions might have required warm and wet conditions that existed in early asteroids but not comets.
Source http://www.nytimes.com/2009/08/19/science/space/19comet.html?ref=space
Study: Fiddler crabs exchange sex for survival
12:06 PM
Beena
SYDNEY --In the world of fiddler crabs, the best form of protection for females is, apparently, having sex with the neighbors, according to an Australian study published Wednesday.
Researchers from The Australian National University in Canberra found male fiddler crabs will happily defend a nearby female against intruders -- partly because the females will dole out sex in return.
"The fact that the neighbor comes over and helps to defend another territorial individual is pretty unusual," said Michael Jennions, who helped conduct the study, the results of which were published in the journal Biology Letters.
"This study shows, for the first time, that in exchange for sex and other benefits, males protect their female neighbors from territory-seeking male intruders. The paper provides the first evidence of 'defense coalitions' between territorial males and females," he said.
Jennions and fellow ANU researchers Richard Milner and Patricia Backwell studied the behavior of fiddler crabs living in mud flats off the African country of Mozambique in October and November 2008. Male fiddler crabs have giant claws to defend themselves, but the researchers wanted to see how female crabs -- which only have two small feeding claws -- protect their homes.
Fiddler crabs are territorial and live in burrows. The researchers gathered crabs from distant parts of the mud flats and tethered them near new, occupied burrows. In 21 trials involving male intruders, the researchers found that male crabs would scuttle over to fight off the invaders on a female neighbor's territory 95 percent of the time. But in 20 trials involving female intruders, the males crabs only fought off the invaders 15 percent of the time.
That suggests the male crabs preferred to keep females nearby, largely because they will almost always have sex with their male neighbors, Jennions said.
Most of the time, female fiddler crabs are selective about their partners and choose to mate in the male's burrow. But the researchers also found females mating on the surface -- and 85 percent of the time the surface sex was with a neighbor. The researchers speculated the female crabs were having the neighborly sex in exchange for some sort of benefit. In this case, that benefit appeared to be protection, Jennions said.
Orpha Bellwood, a lecturer of marine and tropical biology at James Cook University in Townsville, said she was particularly interested in the motivations behind the crabs having sex on the surface, which is unusual and makes them vulnerable to predators.
Bellwood wonders whether it might just be the proximity of the crabs to their own homes that allows them to feel safe enough to mate in the open, or whether the females are indeed gaining some sort of protective advantage by doing so.
"It opens up a lot of those questions," she said.
Peter Davie, senior curator of the Queensland Museum in Brisbane, said the males are known to use their claws to protect themselves.
"But to have that sort of encompass the territories of the females as part of his sexual territory sounds quite interesting," said Davie, who has spent 30 years studying crabs.
Swapping sex for favors is not unheard of in the animal kingdom. Antarctica's Adelie penguins exchange sex for highly coveted stones used for nest building.
Another reason the crabs might help fight off their neighbors' intruders is to keep a familiar comrade next door, Jennions said. Even for crabs, he said, sometimes it's a case of "better the devil you know than the devil you don't."
Researchers from The Australian National University in Canberra found male fiddler crabs will happily defend a nearby female against intruders -- partly because the females will dole out sex in return.
"The fact that the neighbor comes over and helps to defend another territorial individual is pretty unusual," said Michael Jennions, who helped conduct the study, the results of which were published in the journal Biology Letters.
"This study shows, for the first time, that in exchange for sex and other benefits, males protect their female neighbors from territory-seeking male intruders. The paper provides the first evidence of 'defense coalitions' between territorial males and females," he said.
Jennions and fellow ANU researchers Richard Milner and Patricia Backwell studied the behavior of fiddler crabs living in mud flats off the African country of Mozambique in October and November 2008. Male fiddler crabs have giant claws to defend themselves, but the researchers wanted to see how female crabs -- which only have two small feeding claws -- protect their homes.
Fiddler crabs are territorial and live in burrows. The researchers gathered crabs from distant parts of the mud flats and tethered them near new, occupied burrows. In 21 trials involving male intruders, the researchers found that male crabs would scuttle over to fight off the invaders on a female neighbor's territory 95 percent of the time. But in 20 trials involving female intruders, the males crabs only fought off the invaders 15 percent of the time.
That suggests the male crabs preferred to keep females nearby, largely because they will almost always have sex with their male neighbors, Jennions said.
Most of the time, female fiddler crabs are selective about their partners and choose to mate in the male's burrow. But the researchers also found females mating on the surface -- and 85 percent of the time the surface sex was with a neighbor. The researchers speculated the female crabs were having the neighborly sex in exchange for some sort of benefit. In this case, that benefit appeared to be protection, Jennions said.
Orpha Bellwood, a lecturer of marine and tropical biology at James Cook University in Townsville, said she was particularly interested in the motivations behind the crabs having sex on the surface, which is unusual and makes them vulnerable to predators.
Bellwood wonders whether it might just be the proximity of the crabs to their own homes that allows them to feel safe enough to mate in the open, or whether the females are indeed gaining some sort of protective advantage by doing so.
"It opens up a lot of those questions," she said.
Peter Davie, senior curator of the Queensland Museum in Brisbane, said the males are known to use their claws to protect themselves.
"But to have that sort of encompass the territories of the females as part of his sexual territory sounds quite interesting," said Davie, who has spent 30 years studying crabs.
Swapping sex for favors is not unheard of in the animal kingdom. Antarctica's Adelie penguins exchange sex for highly coveted stones used for nest building.
Another reason the crabs might help fight off their neighbors' intruders is to keep a familiar comrade next door, Jennions said. Even for crabs, he said, sometimes it's a case of "better the devil you know than the devil you don't."
November 5, 2009
How Can a Pregnant Woman Get Pregnant Again?
7:45 PM
Beena
An Indonesian woman gave birth to a 19-lb. 2-oz. baby behemoth on Sept. 24, but that was only the second weirdest pregnancy tale of the month. The strangest belongs to Julia Grovenburg, a 31-year-old Arkansas woman who has a double pregnancy. No, not twins — Grovenburg became pregnant twice, two weeks apart. Isn't that supposed to be impossible?
Almost. There have been only 10 recorded cases of the phenomenon, dubbed superfetation. In Grovenburg's case, she became pregnant first with a girl (whom she has decided to name Jillian) and then two weeks later with a boy (Hudson). The babies have separate due dates — Jillian on Dec. 24, Hudson on Jan. 10. (See pictures of pregnant-belly art.)
Dr. Robert Atlas, chairman of the obstetrics and gynecology department at Baltimore's Mercy Hospital, says he has never encountered a case of superfetation during practice. He says such pregnancies occur when a woman continues ovulating after becoming pregnant and when that second, fertilized egg is able to implant itself in the lining of the womb — two things that wouldn't happen in a normal pregnancy. Typically, hormonal changes prevent further ovulation and thicken the lining of the uterus to preclude a second embryo from attaching. Why didn't that happen with Grovenburg? No one's really sure. (See how to prevent illness at any age.)
Despite the rarity of Grovenburg's case, Atlas tells TIME the phenomenon shouldn't be cause for concern. Grovenburg's babies should behave much as twins do; in all likelihood, the second baby will be born slightly premature when Julia first goes into labor. Since the difference between the babies is only two weeks, the second baby will be nearly at full term anyway. Indeed, the last known case of superfetation had a happy ending. In 2007, a British woman gave birth to a boy and girl who were conceived three weeks apart, with no undue complications.
Source www.time.com
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