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.
Malaysia Airlines plane crash exposes alarming flaw in airline security: over one billion flights made last year without stolen-passport check
International Women's Day 2014: The shocking statistics that show why it is still so important
Teacher shows sex tape featuring herself to pupils during class by mistake
Swarm of killer bees sting woman 1,000 times
Dead woman's body found sitting in a car after six years after direct debits ran $54,000 bank account dry
Britain's top vet sparks controversy with call for ban on slashing animals' throats in 'ritual' slaughters for halal and kosher meat products
If you're horrified by a flame-roasted dog, you should be shocked at a hog roast
Poor 'live like animals' says Boris's privately educated sister after going on 'poverty safari'
Exclusive: Impact of immigrants on British workers ‘negligible’
Vince Cable: Teachers 'know absolutely nothing' about the world of work
Ukraine crisis: Russia pledges to 'retaliate against sanctions' as Ukrainian president says Crimea vote will not be recognised
- 1 International Women's Day 2014: The shocking statistics that show why it is still so important
- 2 Australian man Rod Sommerville reacts to bite from deadly snake by reaching for cold beer
- 3 Teacher shows sex tape featuring herself to pupils during class by mistake
- 4 Singapore sting: Sky-high prices are pushing locals to the edge of affordability
- 5 Swarm of killer bees sting woman 1,000 times
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