Our best description of space-time is cracking up. And even as special relativity falls apart, a controversial theory is poised to steal its crown, says David Harris (Boy, will this be huge if and when it happens!)
BEATING THE ODDSRare individuals who somehow manage to defeat HIV unaided are providing crucial leads in the hunt for new treatments and vaccines. Julie Clayton probes their mysterious good health
(just in case you are wondering why some countries are all of sudden pouring billions into AIDS research, tyring to �help Africa�, compa$$ion, blah, blah �)
WORLD WITHOUT AIDS
After two decades of work, the world's most devious virus may finally be about to meet its match. Clare Wilson investigates
Tadpoles take blame for human hiccups 19:00 05 February 03 Exclusive from New Scientist
Why do we hiccup? It's a question that has vexed great minds for millennia and now, at long last, an international team may have come up with the answer.
Hiccups are sudden contractions of the muscles we use to breathe in. Just after the muscles start to move, the glottis shuts off the windpipe, producing the characteristic "hic" sound. Surprisingly, ultrasound scans reveal that babies in the womb start hiccuping after two months, before any breathing movements appear.
That suggests that hiccups in adults are just the remnant of some primitive reflex, which occur only when this brain circuit is accidentally triggered. Yet the purpose of hiccups during pregnancy remains unclear. One theory is that the movements prepare babies' respiratory muscles for breathing after birth, another that they prevent amniotic fluid entering the lungs.
None of these theories explains all the features of hiccups. If their purpose is to prevent liquid getting into the lungs, points out Christian Straus at Pitie-Salpetriere Hospital in Paris, you would expect the closure of the glottis to be associated with the contraction of the muscles used for breathing out, as in a cough, not those for breathing in.
But there is one group of animals in which the peculiar combination of the contraction of these muscles and the closure of the glottis does serve a clear purpose: primitive air breathers that still possess gills, such as lungfish, gar and many amphibians. These animals push water across their gills by squeezing their mouth cavity while closing the glottis to stop water getting into the lungs ----- Ain't science great?Help STOP SPAM with the new MSN 8 and get 2 months FREE*
