What makes your body different from everyone else's? Maybe you're thinking fingerprints or the DNA that you leave on everything you touch. Now, add your breath to that list.
Researchers have found that individuals have unique "breathprints" that change throughout the day and that reflect chemical reactions in the body. In a study reported last week in the journal PLoS One, volunteers blew air into a mass spectrometer, an instrument that can measure the masses and relative concentrations of atoms and molecules. The device split the exhalation into its chemical components. Unlike older methods, which required samples to be prepared and then injected into the machine, the device used in this study can directly accept breath and show the results in seconds.
The researchers found that individuals' breathprints changed slightly from sample to sample, but they always kept a core signature that was unique enough to identify that person. In the future, the authors say, such analysis might reveal the drugs you've been taking or biomarkers of diseases such as cancer.
Smaller versions of the machine may someday make their way into doctors' offices and could be used to detect doping at races without sending samples to a lab.
Everest made easy
See the view from the top of Mount Everest. Peer into the depths of the ocean. View the wilds of the Amazon. Long the stuff of bucket lists, these goals are now attainable on demand through the comfort and relative low cost of your laptop or smartphone.
Google Maps, the GPS tool known for its "street-view" images of locales around the world, has made several exploration-themed additions to its Google Earth service. These include views of the ocean floor's topography and the Amazon rain forest. The latest additions are panoramic images of the world's highest peaks.
The 360-degree views allow users to virtually explore Aconcagua in the Andes, Kilimanjaro in Africa, Mount Elbrus in Russia and Everest's base camp.
"While there's nothing quite like standing on the mountain, with Google Maps you can instantly transport yourself to the top of these peaks and enjoy the sights without all of the avalanches, rock slides, crevasses, and dangers from altitude and weather that mountaineers face," wrote Dan Fredinburg, a member of the expedition team, on Google's blog.
The images were collected with a digital camera with a fisheye lens and a lightweight tripod. They can be viewed on Google's Street View Gallery as well as on iPhone and Android devices.
Total gender bender
If you thought the battle of the genders was complicated, try having seven sexes. When Tetrahymena, a single-celled creature covered in cilia, mates, the offspring isn't necessarily the same sex as either parent-it can be any of seven. Now, researchers have figured out the complex dance of DNA that determines the offspring's sex, and it's a random selection, they reported last week in PLOS Biology. Each Tetrahymena has a gene for its own sex-or mating type-in its regular nucleus, but it also carries a second nucleus used only for reproduction. This "germline nucleus" contains incomplete versions of all seven mating type genes, which are cut and pasted together until one complete gene remains and the other six have been deleted. The newly rearranged DNA becomes part of the offspring's regular nucleus, determining its mating type. Because the mating type gene helps Tetrahymena recognize others of a different sex, the researchers say that the finding could shed light on how other cells, including those in humans, recognize those that are different from themselves.