environmental sciences
Foster care

The large blue butterfly, Maculinea arion, knows how to fool ants into raising their caterpillars. But when the ant, Myrmica sabuleti, disappear there survival is at stake, a study has shown. The butterfly lays eggs on thyme flowers and the caterpillars fall on the ground after hatching. Thanks to a chemical caterpillars secrete, ants mistake them for their own ones, and take the caterpillars to their nests and protect them. When farmers stopped grazing livestock in the English countryside, the vegetation increased and the soil temperature decreased, making it unsuitable for the ant. With the ants gone, there was nothing to protect the butterfly. The study was published online on Science Express on June 18, 2009.

chemical sciences
The cyanide flip

Catalytic converters are used in vehicles to reduce toxins in the exhaust. But the reaction by which they convert toxic gases into harmless ones was not understood. To crack this scientists simulated the condition inside a catalytic converter; they placed a catalyst in the midst of toxic gases. The catalyst was made of silver nanoparticles deposited on aluminium oxide. A laser beam aimed at the catalyst triggered a reaction that was analyzed by infrared spectrometer. The analysis showed that in the intermediate reaction between gases like carbon monoxide and nitrogen oxide, a cyanide group was formed. The silver nanoparticles flipped it over to aluminium oxide. This made the gases harmless. The study, reported in the May 22 issue of Science, makes way for improved catalytic converters.

archaeology
New dating method

Scientists have devised an alternative to carbon dating to find the age of clay objects. This technique uses the rate at which clay objects absorb moisture after they are fired in the kiln. Older the material, the heavier it is due to water absorption. The team measured the rate of weight gain using a microbalance. The study was published in the May 20 online issue of the Proceedings of the Royal Society A.

human physiology
Brain talks gamma

The brain works through an interplay of neurons in its planning centre, the prefrontal cortex. When the brain is paying attention to an object, neurons work in unison in the planning centre, producing signals which are conveyed to the brain