The extent of Arctic sea ice has been diminishing since the late 1970s due to climate change, and this decline is predicted to continue in the coming decades. The prospect of open water in these previously icy areas has sparked a lot of speculation about ships being able to navigate between the Pacific and Atlantic Oceans through the Northwest Passage or over the North Pole.
Next time you’re in the supermarket weighing
the glossy conventional fruit against the small, blotched organic alternative, consider this: organic fruits’ stunted size may be the signal of their nutritional prowess.
Various studies in recent years have shown that some organic fruits and vegetables have nutritional advantages over conventionally-grown produce. For instance, organic tomatoes contain more vitamins, and organic tomato juice has more phenolics, a class of molecules that promote the body’s own antioxidant response.
But it’s been unclear exactly how organic farming brings about these changes in fruit. Now a new study indicates that the secret is stress: While conventional fruits are coddled by synthetic fertilizers, organic plants have fewer minerals available to them—and they therefore produce fruit that’s higher in human-healthy compounds.
DEET is the mother of all mosquito repellants. Its strong stench keeps bugs at bay by affronting their olfactory systems with an intensely offensive odor. But scientists are now running into a problem with DEET’s effectiveness: after three hours the stuff no longer deters buzzing biters.
N,N-Diethyl-3-methylbenzamide, a.k.a. DEET, first emerged as a pesticide for crops, but the U.S. military then developed the chemical for use against biting insects in jungle environments during World War II. Available as a spray or a lotion, DEET is still used today to repel flies, ticks and mosquitoes, and to protect against the diseases these bugs can transmit.
But now, researchers in London have shown that three hours after Aedes aegypti mosquitoes were exposed to DEET, they seemed to become immune to the smell and were no longer repulsed by it. This species, also known as the yellow fever mosquito, is notorious for spreading tropical diseases.
Paleontologists in California announced this week that fossils excavated in the early 2000s represent four new species of ancient whales. The toothed baleen whales apparently stuck around longer than scientists once thought, and they may hold clues about how and when whales evolved from toothy giants to the baleen-equipped beasts we see today.
“Must be something in the water” isn’t just a line from the opening minutes of a horror movie.
New evidence confirms fears that animals’ behavior can be altered by medication inadvertently introduced into their habitats via our sewage systems.
In a study published today Swedish researchers report that fish given Oxazepam, an anxiety-moderating drug for humans, became less social and more aggressive. Researchers administered the drug to wild perch in the lab in amounts equivalent to levels found in local rivers and streams.
The dosed fish showed a number of behavioral changes, notably in their willingness to leave familiar and “safe” surroundings in favor of exposed, potentially dangerous areas. The fish treated with the drug also distanced themselves from other perch. These antisocial fish ate faster than normal, which, in the wild, could disrupt the established food chain.
City lights at night make pretty views from space, but they’re not so good for sleeping. To overcome a messed up inner clock, many urban dwellers have learned to use light-blocking curtains or eye masks. But people aren’t the only ones who have to adjust to this unnatural illumination. Blackbirds, too, are exposed to this nighttime glow, and it actually makes them mature and moult sooner.
Reproduction is a seasonal ritual for birds, hence the term mating season, and they take their cues from their environment. Light is one of the factors that impacts the initiation of sexual maturity, and being exposed to light during the night appears to throw off this natural cycle.
Sockeye salmon put on a lot of miles during their short life
. From the freshwater riverbeds where they hatch and spend their first couple years, juvenile salmon travel some 4,000 miles to the ocean where they fatten up for two years before turning around and retracing their steps.
But salmon can’t leave actual footprints, nor do they have the luxury of dropping waterproof bread crumbs so they can find their way back home. Scientists have long suspected that these big fish instead use the Earth’s magnetism to orient their inner compass. A recent study of 56 years’ worth of migration data presents pretty convincing evidence for this geomagnetic hypothesis and how it works.
In their search for the lost grave of King Richard III, archaeologists unearthed a skeleton from underneath a parking lot last August. Today researchers announced that the skeleton is indeed that of England’s 500-year-deceased
king, and they have the DNA and radiocarbon dating to prove it.
Richard III is most famous for the Shakespeare play of the same name, which was written a century after his death. This English king reigned for just over two years, but his body was buried without record of its exact location. Researchers began digging up the vicinity of Greyfriars church in Leicester in 2011, and today’s announcement is the scientific evidence they needed to make their case for a definitive identification.
What causes wind? Any elementary science textbook will tell you it’s about pressure differences: Hot air rises and cool air rushes into the void, creating wind in the process. This is the driving force of our climate system as a whole. The existing paradigm relies on temperature alone to create these pressure differences, but new numbers suggest that a much less conspicuous driver of air movement—condensation—may actually be dictating the planet’s weather patterns.
Domestic cats are known killers, and when let loose they can
do real predatory damage. Cats (Felis catus) can wipe out entire populations of native birds and small mammals such as mice, squirrels and rabbits when introduced to island environments. Eradication efforts have historically been implemented to remove these non-native predators from islands. A new study shows that domestic cats can wreak havoc on the mainland as well. Researchers say un-owned cats kill far more birds and mammals than previously thought, making them the greatest human-related cause of these wildlife deaths in the United States.