One in every 30 babies born in the United States in 2009 was a twin, a dramatic increase from the one-in-53 babies born a twin in 1980, a new study finds.

Researchers attribute the rise in twin birth rates, in part, to the growing number of women having children at older ages, and the expanding availability of fertility treatments.

"Prior to 1980, the incidence of U.S. twin births was stable at about 2 percent of all births, but it has risen dramatically in the past three decades," said Barbara Luke, a researcher at Michigan State University's College of Human Medicine's Department of Obstetrics, Gynecology and Reproductive Biology.

While the increase in twin birth rates held true for mothers of all ages, the largest increase was seen among women aged 30 and older.

"Older maternal age accounts for about one-third of the rise, and two-thirds is due to the increased use of fertility treatments," including both assisted reproductive technologies and ovulation stimulation medications.

Radio telescopes in Australia and South Korea have linked up for the first time, forming a mega-instrument roughly 5,000 miles (8,000 kilometers) across.

The transcontinental scope should have roughly 100 times more resolving power than NASA's Hubble Space Telescope, researchers said. It continues Australia's astronomy partnership with Asia; the country has also made similar linkups with Japan and China over the years.

"This is another step in Australia's ongoing collaboration with Asia in the field of radio astronomy," Philip Diamond, astronomy chief at Australia's national science agency, known as CSIRO (Commonwealth Scientific and Industrial Research Organisation), said in a March 15 statement.

Five telescopes were involved in the new linkup. Three of them are Australian, two in the state of New South Wales and one near Hobart, in Tasmania. The two Korean scopes are in the capital, Seoul, and Ulsan, a city in the southeast of the country, researchers said. [The World's 10 Biggest Telescopes]

Mark your calendars! On June 5-6, a rare celestial event called a transit of Venus will take place, and it won't be repeated in your lifetime.

During the transit, Venus will pass directly in front of the sun from Earth's perspective, appearing as a small, slowly moving black dot. The last time this happened was in June 2004, but the next one won't take place until December 2117. This is the last chance for anyone alive today to see the rare celestial sight.

Why would the well-heeled suburb of Gilbert, Ariz., spend a quarter of a million dollars on a futuristic spy gadget that sounds more at home in a prime-time drama than a local police department?

The ACLU caused a stir Monday with its extensive report of cellphone surveillance by local police departments, which routinely request location information and other data from cellphone providers, often under vague legal circumstances.

But one bit of information provided by Gilbert officials suggests that cops sometimes try to cut out the middle man. Buried in the 380 public records requests sent by the ACLU is a response from Gilbert which indicates that the town purchased a device that allows it to track cellphones on its own for $244,195.
"The Gilbert Police Department obtained a $150,000 grant from the State Homeland Security Program," the agency wrote to the ACLU in response to a public records request. "These funds, along with $94,195 of R.I.C.O monies, were used to purchase cell phone tracking equipment in June 2008 (total acquisition cost of $244, 195)."

The US has reportedly drawn up plans for a new generation of nuclear-powered drones capable of carrying more missiles or surveillance equipment and flying over more remote regions of the world for months.

"It's pretty terrifying prospect," said Chris Coles of Drone Wars UK, which campaigns against the increasing use of drones for both military and civilian purposes.

"Drones are much less safe than other aircraft and tend to crash a lot. There is a major push by this industry to increase the use of drones and both the public and government are struggling to keep up with the implications," he added.

The blueprints for the new drones have been developed by Sandia National Laboratories - the US government's principal nuclear research and development agency - and defense contractor Northrop Grumman.

Chicago - B iomedical researchers talk about the day not too far off when DNA sequencing will be so cheap that everyone will have their genome sequenced and carry the results around on a flash drive. People will learn about their personal disease risks, helping their doctors and them prevent or treat these illnesses. But a new study throws cold water on the notion that whole-genome sequencing will be very useful for the average person.

Hopes for genomic medicine have grown in the past few years as researchers raced to track down DNA behind common diseases. These so-called genome-wide association studies have turned up hundreds of genetic markers linked to diseases such as cancer and diabetes. But the risks associated with such markers are usually quite low - often just a fraction higher than for people without the marker. Still, many scientists have hoped that once they found all the genetic markers for a disease, including rare ones that confer higher risk, the total risk carried by some individuals would be high enough - say, two times the normal risk - to merit taking preventive measures.

But the new study suggests that even if all the disease risk markers can be found, the genetic risk for most people will still be relatively low. This conclusion emerges from a study by cancer geneticists Victor Velcelescu, Bert Vogelstein, and colleagues at Johns Hopkins University. They began by gathering existing data sets on diseases in thousands of twins, mostly in Europe. They assumed that identical twins have the same genetic risk of developing a specific disease. After examining 24 actual diseases in the twins, the researchers constructed a model that assumes each individual carries a certain "genometype," or total genetic risk, for each disease. Then they looked at how these risks would vary across the population.

Cattle aren't known for their intelligence. Perhaps it's because their family tree has a very skinny trunk.

Genetic evidence suggests all "taurine" cattle (the most commonly recognized breed) descend from only about 80 females and came from a single region in what is now Iran about 10,500 years ago. A study in the journal Molecular Biology and Evolution traced the modern global herd's heritage back to its ancestral home on the range.

The study compared mitochondrial DNA extracted from 15 preserved ancient cattle's bones to modern cattle and found little variation. Little variation meant the founding population didn't have many different versions of the mitochondrial genes to start with.

Earlier research published in PloS ONE suggested that taurine cattle may have later received a small genetic boost from European aurochs. Aurochs were the super-sized ancestors of our modern hamburger on the hoof.

The size and nasty disposition of the wild auroch (Bos primigenius) would have made it a formidable beast to tame for the ancient Iranians. That difficulty is possibly why domestication only occurred with a small number of animals. The authors of the paper in Molecular Biology and Evolution suggested that only humans who had settled down into villages would have had the ability to domesticate the auroch.

The recent explosion in the number of retractions in scientific journals is just the tip of the iceberg and a symptom of a greater dysfunction that has been evolving the world of biomedical research say the editors-in-chief of two prominent journals in a presentation before a committee of the National Academy of Sciences (NAS) today.

"Incentives have evolved over the decades to encourage some behaviors that are detrimental to good science," says Ferric Fang, editor-in-chief of the journal Infection and Immunity, a publication of the American Society for Microbiology (ASM), who is speaking today at the meeting of the Committee of Science, Technology, and Law of the NAS along with Arturo Casadevall, editor-in-chief of mBio®, the ASM's online, open-access journal.

Two of the solar system's best natural timekeepers have been caught misbehaving, suggesting that the accepted ages for the oldest known rock samples are off by a million years or more.

According to two new studies, a radioactive version of the element samarium decays much more quickly than previously thought, and different versions of uranium don't always appear in the same relative quantities in earthly rocks.

Both elements are used by geologists to date rocks and chart the history of events on our planet and in the solar system.

"If you have a critical event in Earth's history, something like an extinction event or a climate change shift or a meteorite impact, you need to know the absolute age with the most confidence," says Joe Hiess of the British Geological Survey, who led one of the studies. "In Earth sciences there's a need to be able to define what happened first and what happened second."

Physicists at the University of California, San Diego have discovered patterns which underlie the properties of a new state of matter.

In a paper published in the March 29 issue of the journal Nature, the scientists describe the emergence of "spontaneous coherence," "spin textures" and "phase singularities" when excitons - the bound pairs of electrons and holes that determine the optical properties of semiconductors and enable them to function as novel optoelectronic devices - are cooled to near absolute zero. This cooling leads to the spontaneous production of a new coherent state of matter which the physicists were finally able to measure in great detail in their basement laboratory at UC San Diego at a temperature of only one-tenth of a degree above absolute zero.

The discovery of the phenomena that underlie the formation of spontaneous coherence of excitons is certain to produce a better scientific understanding of this new state of matter. It will also add new insights into the quirky quantum properties of matter and, in time, lead to the development of novel computing devices and other commercial applications in the field of optoelectronics where understanding of basic properties of light and matter is needed.