Published: Tuesday 15 May 2007

For better brain A team of scientists in the US has found that exercise has links to brain cell regeneration. The team first looked at the brains of exercising mice using magnetic resonance imaging to follow blood flow through the brain. On post mortem testing, they found that brain cell creation or neurogenesis correlated with increased blood flow in the hippocampal formation. They then looked at humans and found similar results with the blood flow correlating to heart function and cognitive ability. The hippocampal region is particularly associated with memory and indicated in the degeneration due to ageing.

Clawing on It's not human beings alone, male crayfish too are dishonest, scientists have discovered. Crayfish are a naturally aggressive species and will squabble over almost anything, say researchers. They have found that crayfish use claw size to determine the winners of the most aggressive disputes.After measuring the size and strength of claws of male and female crayfish, the scientists found that the claw size of males was not a good indicator of their strength, compared to the female crawfish. Males routinely bluff their opponents with weak claws to achieve dominance, say researchers.

Tracking the king Scientists at the University of Birmingham are studying the behaviour of penguins to investigate whether they can be used to monitor the effects of climate change. "If penguins are travelling further or diving deeper for food, that tells us something about the availability of particular fish. We may be able to assess the pressure exerted by king penguins on this ecosystem, and look at the effects of both climate change and overfishing in this region of the world," say researchers. King penguins are good bio-indicators because their diet is well known and they are easy to track.

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