If our eyes could see radio waves, the nearby galaxy Centaurus A (Cen A) would be one of the biggest and brightest objects in the sky, nearly 20 times the apparent size of a full moon.
What we can't see when looking at the galaxy in visible light is that it lies nestled between a pair of giant radio-emitting gas plumes ejected by its supersized black hole. Each plume is nearly a million light-years long.
NASA's Fermi Gamma-Ray Space Telescope maps gamma rays, radiation that typically packs 100 billion times the energy of radio waves. Nevertheless, and to the surprise of many astrophysicists, Cen A's plumes show up clearly in the satellite's first 10 months of data. The study appears today in Science Express.
A team of paleontologists said this week that some sauropod species went through drastic changes in skull shape during normal growth.
Researchers came to the conclusion after examining the The skull of a juvenile sauropod dinosaur, rediscovered in the collections of the Carnegie Museum of Natural History.
The fossil offers a rare chance to look at the early life history of Diplodocus, a 150 million-year-old sauropod from western North America.
The researchers believe these changes in skull shape may have been tied to feeding behavior, with adults and juveniles eating different foods to avoid competition. Young Diplodocus, with their narrower snouts, may also have been choosier browsers, selecting high quality plant parts.
Tracking 18- to 21-year-old men enlisted in the Israeli army, researchers from Tel Aviv University say they have demonstrated an important connection between the number of cigarettes young males smoke and their IQ--young men who smoke are likely dumber than their non-smoking peers.
The average IQ for a non-smoker was about 101, while the smokers' average was more than seven IQ points lower at about 94, the study determined. The IQs of young men who smoked more than a pack a day were lower still, at about 90. An IQ score in a healthy population of such young men, with no mental disorders, falls within the range of 84 to 116.
Small sales taxes on soft drinks are insufficient to reduce consumption of soda or curb obesity among children, according to a new a new study in Health Affairs.
Such small taxes may reduce consumption in some subgroups, such as children at greater risk for obesity. But to reduce overall soda consumption, the taxes would have to be downright draconian, structured as excise taxes that would increase the shelf price of the product rather than sales taxes collected at the cash register.
An 18 percent soda tax proposed and then dropped from New York's Executive Budget last year, for example, could help prevent excessive weight gain between third and fifth grades by 20 percent, the authors say.
Geologists have long thought that the rapid global cooling period nearly 13,000 years ago known as the Younger Dryas (Big Freeze) was triggered by the melting Laurentide ice sheet. But geological evidence for that theory has been lacking so far.
Now researchers writing in Nature say they have identified the mega-flood path across North America that channeled melt-water from the giant ice sheet into the oceans, triggering the Younger Dryas cold snap.
Researchers from Uppsala and Stockholm Universities say that the hunter-gatherers who inhabited the southern coast of Scandinavia 4,000 years ago were lactose intolerant.
The conclusion suggests that today's Scandinavians are not descended from the Stone Age people in question but from a group that arrived later. Results of the research have been published in the journal BMC Evolutionary Biology.
"This group of hunter-gatherers differed significantly from modern Swedes in terms of the DNA sequence that we generally associate with a capacity to digest lactose into adulthood," says Anna Linderholm, formerly of the Archaeological Research Laboratory, Stockholm University.
Silicon is the basic material for most microprocessors and memory chips. But for a long time the electronics industry has been pursuing novel organic materials to create semiconductor products—materials that perhaps could not be packed as densely as state-of-the-art silicon chips, but that would require less power and cost less.
According to scientists at the National Institute of Standards and Technology (NIST), an organic semiconductor may be a viable candidate for creating large-area electronics, such as solar cells and displays that can be sprayed onto a surface as easily as paint.
How quickly the Andes Mountains reached their current height, an average elevation of 13,000 feet, has been a contentious debate in geological circles. Some researchers claim the mountains rose abruptly and others maintain that the uplift was a more gradual process.
Paleoclimatologists writing in Science suggests that the quick-rise view is based on misinterpreted evidence. What some geologists interpret as signs of an abrupt rise are actually indications of ancient climate change, the researchers say. The confusion results when ratios of oxygen's two main isotopes, oxygen-18 and oxygen-16, are used to estimate past elevation.
However cute they may be, fat babies are likely to develop motor skills slower than their thinner counterparts, says a study just published in the Journal of Pediatrics.
The findings are based on observations of 217 African-American first-time mothers who participated in the Infant Care, Feeding and Risk of Obesity Study. The project is examining – in a population at risk of obesity – how parenting and infant feeding styles relate to infant diet and the risk of babies becoming overweight.