Science Briefs – May 3, 2011
Kelsey Gobroski / Sun Star Reporter
May 3, 2011
Fire ants float
Some fire ants clump to one another to construct living rafts. A new study demonstrates how the fire ants can form a floating structure where they would sink if alone. They grip one another in just the right structure to remain afloat. In floods, they adhere to one another to become buoyant, such as during Hurricane Katrina. The colonies also transform into ladders, chains and walls.
Sleep remains difficult to define
Parts of an individual’s brain can go to sleep even while the organism is awake, according to scientists in Wisconsin. Some cells in rats’ brains go “offline” in a way that resembled sleep when the animal had been awake for a long time. Scientists compared the phenomenon to boiling water: the animal was awake, then slowly “bubbles” of sleeping cells popped up, impossible to predict and increasing as the rat stayed awake. Eventually, the rats had trouble performing tasks. During regular sleep, not all cells were sleeping, so not all cells are active or inactive while an individual is asleep or awake.
– Nature News
Turtles indirectly consume pesticides
A South Carolina graduate student tracked loggerhead sea turtles up the East Coast and discovered the chemicals they ran into along the way. When the group took blood samples from the turtles at the beginning of the study, they found 67 different types of industrial products, including pesticides. The turtles started out in Florida, and those that traveled up to New England had more pollutants than those that stayed in Florida. Perhaps the New England fish are a more polluted food source, or perhaps the migrating turtles need to eat more to offset the energy they spend on their journeys, the scientists said. The adults were able to reproduce and appeared healthy.
– New York Times