Science: Theoretically ...
Monday 09 December 1996
Why don't models of ozone depletion in the Arctic match reality? Because, say a team in Paris in the latest Nature, the computer models can't reproduce the tiny variations in spatial distribution of the ozone-eating chemicals. These could account for big discrepancies between forecast and observed ozone depletion around the North Pole, they say. While models work well with the Antarctic, the polar air circulation is less uniform in our hemisphere. To back up their suggestion, the researchers used an ultra high-resolution model to show that ozone depletion really is sensitive to small-scale differences. For the winter of 1994-95, the effect is large enough to account for the Arctic ozone depletion being 40 per cent greater than models predicted.
The River Nile's great bend, where it zigzags from its northerly path to head southwest for almost 200 miles before heading north again, is probably due to tectonic forces. A report in Science based on radar-sensing data from the Nasa space shuttle suggests that the southwesterly movement is comparatively recent, caused by geological uplift from faults in younger rock beneath it. The northwards flow dates from Precambrian strata. So it's not civil engineering to make the cruises longer.
Family-linked cases of Alzheimer's disease tend to occur at an earlier age than the "spontaneous" forms. The role of the genetic link - a gene known as PS2 - is becoming clearer. New US research has found that PS2 mutation produces a molecule which makes neurons more likely to commit "cell suicide" (apoptosis). Perhaps, say the team at the National Institutes of Health in Bethesda, Maryland, the molecule makes neurons more sensitive to the "normal insults" of ageing, adding to the toxic burden in the patients' brains.
Massively fat, diabetic and infertile: it's no fun being a mouse deficient in leptin. That's the hormone encoded by the "Ob" (for obese) gene which helps you lose weight by suppressing appetite and stimulating your metabolism. But as dieters will have suspected, leptin isn't the only player in the weight charades. A neuropeptide called NPY, known to regulate energy balance, reaches high levels in leptin-deficient mice. But mice that don't produce leptin or NPY are less obese than their leptin-deficient mates and suffer less from diabetes or sterility. Gene therapy for weight loss? The day might not be far off. It's just that you would have to mediate a lot of genes.
- 1 PlayStation and Xbox hacked by Lizard Squad
- 2 Christmas comes early to Hong Kong, as millions of bank notes spill out onto busy street
- 3 The 'Black Museum': After 150 years, public set to see exhibits from police’s grisly crime museum
- 4 British actor Idris Elba cannot star as James Bond because he is black, says shock jock Rush Limbaugh
- 5 Vagina canoe artist defends herself over ‘obscenity’ charges
PlayStation and Xbox hacked by Lizard Squad
Antonio Martin shooting: Black teenager may have tried to ambush patrolman, says police officer's lawyer
Katie Hopkins speaks out on childhood obesity: 'Parents of fat children should be prosecuted for child cruelty'
Boxing Day snowfall set to push even more bargain-hunters online for sales
The 'Black Museum': After 150 years, public set to see exhibits from police’s grisly crime museum
British actor Idris Elba cannot star as James Bond because he is black, says shock jock Rush Limbaugh
Rozanne Duncan: Ukip expels councillor for 'jaw-dropping' comments made in BBC TV interview
Germany anti-Islam protests: 17,000 march on Dresden against 'Islamification of the West'
Ukip member gets into Christmas spirit with Union Flag plea to Santa 'for our country back'
BBC director Danny Cohen: Rising UK antisemitism makes me feel more uncomfortable than ever
Alex Salmond has 'broken his word to the Scottish people' says Scottish Lib Dem leader
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