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LOS ANGELES, May 2 (Xinhua) -- An asteroid will fly past Earth this fall at a close approach that will allow a close-up view of one of Earth's good-sized space rocks, NASA's Jet Propulsion Laboratory (JPL) announced on Monday."On November 8, asteroid 2005 YU55 will fly past Earth and at its closest approach point will be about 325,000 kilometers away," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the JPL in Pasadena, Los Angeles."This asteroid is about 400 meters wide -- the largest space rock we have identified that will come this close until 2028."Despite the relative proximity and size, "YU55 poses no threat of an Earth collision over, at the very least, the next 100 years, " Yeomans said in a press release."During its closest approach, its gravitational effect on the Earth will be so miniscule as to be immeasurable. It will not affect the tides or anything else.""While near-Earth objects of this size have flown within a lunar distance in the past, we did not have the foreknowledge and technology to take advantage of the opportunity," said Barbara Wilson, a scientist at JPL. "When it flies past, it should be a great opportunity for science instruments on the ground to get a good look.""The best resolution of the radar images was 7.5 meters per pixel," said JPL radar astronomer Lance Benner. "When 2005 YU55 returns this fall, we intend to image it at 4-meter resolution with our recently upgraded equipment at the Deep Space Network at Goldstone, California. Plus, the asteroid will be seven times closer. We're expecting some very detailed radar images."Asteroid 2005 YU55 was discovered in December 2005 by Robert McMillan, head of the NASA-funded Spacewatch Program at the University of Arizona, Tucson. The space rock has been in astronomers' crosshairs before.In April 2010, Mike Nolan and colleagues at the Arecibo Observatory in Puerto Rico generated some ghostly images of 2005 YU55 when the asteroid was about 2.3 million kilometers from Earth.

WASHINGTON, May 17 (Xinhua) -- A variation in a gene involved in regulating cholesterol in the bloodstream also appears to affect progesterone production in women, making it a likely culprit in a substantial number of cases of their infertility, a new study from Johns Hopkins University researchers suggests.The Hopkins group has also developed a simple blood test for this variation of the scavenger receptor class B type 1 gene ( SCARB1) but emphasized there is no approved therapy yet to address the problem in infertile women.Following up studies in female mice that first linked a deficiency in these receptors for HDL -- the so-called "good" or " healthy" cholesterol -- and infertility, researchers report finding the same link in studies of women with a history of infertility.The findings has been published on-line this week in the journal Human Reproduction.If the new study's findings hold up on further investigation, the John Hopkins team says they not only will offer clues into a genetic cause of some infertility, but could also lead to a treatment already shown to work in mice."Infertility is fairly common and a lot of the reasons for it are still unknown," warns endocrinologist Annabelle Rodriguez, an associate professor of medicine at the Johns Hopkins University School of Medicine and the lead author. "Right now, the benefit of this research is in knowing that there might be a genetic reason for why some women have difficulty getting pregnant. In the future, we hope this knowledge can be translated into a cure for this type of infertility."

LOS ANGELES, May 15 (Xinhua) -- Using a simple, minimally- invasive technique to analyze cells from the interior of the nose, U.S. researchers have detected lung cancer in its earliest stage.For the study, the researchers at the Boston University Medical Center collected nasal epithelial cells from thirty three smokers who were undergoing medically-indicated bronchoscopies for suspicion of lung cancer, according to the American Association for the Advancement of Science (AAAS) on Sunday.Of these patients, 11 were found to have benign disease and 22 had lung cancer. Brushings were taken from the right or left nostril and profiled on microarrays, a process that allows researchers to study gene expression changes.The researchers identified 170 genes that were differentially expressed between patients with and without lung cancer. They also found that genes linked to colon cancer and adenocarcinoma, as well as genes that trigger cell division and blood vessel growth, were expressed more heavily in patients with cancer. Genes involved in tumor suppression were also expressed at lower levels in these patients.Earlier studies have used gene expression differences in the bronchial airways to identify lung cancer in its early stages. The researchers relied on those results to design the current study."In this study we used the same principle as we used in our earlier studies of bronchial tissue, only this time, those methods were used to study nasal cells," said study author Christina Anderlind, MD, Instructor of Medicine. "Our hypothesis was that the upper airway epithelium of smokers with lung cancer displays a cancer-specific gene expression pattern, and that this airway nasal gene expression signature reflects the changes that occur in lung tissue."

WASHINGTON, April 3 (Xinhua) -- In the largest study of its kind, researchers from a consortium led by the University of Pennsylvania School of Medicine, the University of Miami, and the Boston University School of Medicine, identified four new genes linked to Alzheimer's disease. The findings appeared Sunday in the current issue of Nature Genetics.Each gene individually adds to the risk of having this common form of dementia later in life. These new genes offer a portal into what causes Alzheimer's disease and is a major advance in the field.The study, conducted by the Alzheimer's Disease Genetics Consortium, reports genetic analysis of more than 11,000 people with Alzheimer's disease and a nearly equal number of elderly people who have no symptoms of dementia. Three other consortia contributed confirming data from additional people, bringing the total number of people analyzed to over 54,000. The consortium also contributed to the identification of a fifth gene reported by other groups of investigators from the United States, the United Kingdom, France, and other European countries.The study is the result of a large collaborative effort with investigators from 44 universities and research institutions in the United States, led by Gerard Schellenberg at University of Pennsylvania."This is the culmination of years of work on Alzheimer's disease by a large number of scientists, yet it is just the beginning in defining how genes influence memory and intellectual function as we age. We are all tremendously excited by our progress so far, but much remains to be done, both in understanding the genetics and in defining how these genes influence the disease process," Schellenberg said.Until recently, only four genes associated with late-onset Alzheimer's have been confirmed, with the gene for apolipoprotein E-e4, APOE-e4, having the largest effect on risk. The Nature Genetics studies add another four -- MS4A, CD2AP, CD33, and EPHA1 -- and contribute to identifying and confirming two other genes, BIN1 and ABCA7, thereby doubling the number of genes known to contribute Alzheimer's disease.

You can think of NASA's Discovery program as a sort of outer-space American Idol: every few years the agency invites scientists to propose unmanned planetary missions. The projects have to address some sort of fundamental science question, and (this is the tough part) they have to be relatively cheap to pull off — say, half a billion dollars or so. Then the proposals go through a grueling competition before judges who aren't as nasty as Simon Cowell but who are every bit as tough. The one left standing at the end gets the equivalent of a recording contract: NASA supplies the funding and the launch vehicle, and away the winner goes — to orbit Mercury, as the Messenger spacecraft is doing right now; or to rendezvous with a couple of asteroids, as the Dawn mission will start doing this July; or to smash into a comet on purpose, a feat achieved by Deep Impact in 2005, a mission not to be confused with the movie of the same name. Now it's time for the next contenders. NASA has just announced that the first round of the latest Discovery competition is over, with three entries out of 28 moving on to the finals. They are, in increasing distance from Earth: the Geophysical Monitoring Station (GEMS) lander, which would use seismometers to study the interior of Mars; the Comet Hopper, which would do just that, leaping from place to place across the surface of Comet 46P/Wirtanen to see how different parts of the tumbling body react to heating by the sun; and the Titan Mare Explorer (TiME), which would plop into a sea of liquid hydrocarbons on Saturn's moon Titan — the first oceangoing vessel ever to set sail on another world. If you had to come up with a theme that ties all three missions together, it would be "origins." The Titan explorer, for example, will be studying a place that — in a crude way, at least — resembles the early planet Earth at a time when life arose here. Titan, with a thick atmosphere and a bizarro-world form of weather featuring toxic winds and hydrocarbon rain, is home to a mix of complex chemistry, complete with organic molecules. The oceans provide a medium in which the molecules can move around and interact with each other. It's even conceivable, though clearly a long shot, that some form of microscopic life already exists on this frigid moon. The Mars lander, by contrast, would visit a place where the seas — plain water in this case — vanished long ago. But the mission of GEMS goes far deeper than that. By analyzing Marsquakes on the Red Planet, GEMS will try to get a handle on what the interior of Mars is like. Scientists don't currently know whether the planet's core is liquid, like Earth's, or solid, or some mushy consistency in between. It all depends on how efficiently Mars has cooled since it formed 4.5 billion years ago, and that depends in turn on the planet's internal structure. "That's the mission," says Bruce Banerdt, of NASA's Jet Propulsion Laboratory, the lead scientist for GEMS. "We want to understand how Mars was built." Along with sensitive seismographic equipment, GEMS will drill down about 20 ft. (6 m) with a thermometer-equipped probe, trying to figure out how quickly the temperature rises with depth. "That will let us extrapolate all the way down to the center," Banerdt says, "which will tell us how fast Mars is cooling."

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