'Supergene' that paints butterflies is pinpointed
Scientists have found a "supergene" that paints the stripes, spots and rays on a surprisingly diverse range of butterflies. Butterfly wings provide an opportunity for scientists to understand how nature creates patterns and reveal how new species evolve, such as the non-poisonous butterflies that mimic the wings of poisonous types that birds avoid. A genetic study of a range of South American butterflies, published yesterday in the journal PLoS Biology, has found that the same molecular pattern-forming machinery is at work in three different species of Heliconius butterflies: Heliconius melpomene and Heliconius erato , which look the same, and Heliconius numata , which looks different.
The Daily Telegraph
Cancer screening computer advance
Checking mammograms with the aid of computers could dramatically speed up breast cancer screening, according to a new study. Cancer Research UK scientists found that using computers as well as experts could cut the work of radiologists in half. At present, two experts usually check the X-rays, but one expert and a computer gave better results, the study found. The computer-aided detection programme scans the mammograms for suspicious features or irregularities that could be caused by cancer tumours. When the computer finds anything unusual, it marks it out on a screen for a radiologist to check.
The Guardian, The Scotsman
Global warming nears a million-year high
The Earth's rapid warming has pushed temperatures to their hottest level in nearly 12,000 years – and a hair’s breadth away from a million-year peak – according to a Nasa study. Global warming, which has increased temperatures by 0.2°C per decade over the past 30 years, has caused temperatures to reach and now pass through the warmest levels in the current interglacial period, which lasted almost 12,000 years. The study, led by James Hansen and colleagues at Nasa's Goddard Institute for Space Studies, reports that Earth is now within about 1°C of the maximum estimated temperature of the past million years. "That means that further global warming of 1°C defines a critical level.”
Menthol cigarettes harder to give up, study shows
Menthol cigarettes are as harmful to your health as conventional cigarettes - and even harder to give up, according to a study. Research carried out in the US has found that menthol and non-menthol cigarettes appear to be equally harmful to the arteries and to lung function. But smokers of mint-flavoured tobacco appear to find it even more addictive. Those who quit are almost twice as likely to relapse as smokers of non-mentholated tobacco, and they are far less likely to stop for a sustained period and less likely to try to give up in the first place.
More plants make more rain
More rain makes for more plant growth: that much is obvious. But now a statistical study of satellite images has added weight to the reverse notion: more plants also make for more rain. The result adds to the impetus to preserve green spaces in dry regions, in order to help prevent deserts from growing and encroaching on agricultural land. Greenery can have a number of effects on a local climate. Plants are thought to transfer moisture from the soil into the air by evaporation from their leaves, and hold water in the soil close to the surface, where it can also evaporate.
One in 10 expectant mothers suffer depression
Depression during pregnancy may be almost as common as post-natal 'baby blues', new research suggests. Typically up to one in seven new mothers experience depression after the birth of their child. Experts say the problem may be triggered by current pressures to copy celebrity mums and the stress of combining busy working lives with pregnancy. The barrage of tests that expectant mothers now undergo may also have helped transform pregnancy from a time of happy expectation into one of anxious waiting for some.
The Daily Mail