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What doesn't kill you…
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interesting.” Then he goes into denial: “They cast no doubt whatsoever on the theory of the selfish gene.” Finally, he provides himself with an escape route by suggesting we replace the precise word “gene” with the vague “replicator”. We also learn that the job of a replicator is to “replicate accurately, the occasional mutation aside”. Well, thanks a lot, mate. Very illuminating. Shaftesbury, Dorset, UK
Cut! From Hugh Young, www.circumstitions.com The three trials of circumcision in Africa that were curtailed (19 July, p 40) suffered from other problems too. I calculate from the published results that more than twice as many circumcised men dropped out (327) – their HIV status unknown – as the number of non-circumcised men who were eventually found to have HIV (137). Trial participants were encouraged to be tested elsewhere, it being considered unethical to tell them the results found in the trial. To find you had HIV after a painful operation to prevent it would be a powerful inducement not to go back. Brian Morris is reported as claiming that circumcising 1000 baby boys will prevent one case of penile cancer. A fast surgeon may do 40 circumcisions in a day, so that’s 25 days’ surgery to prolong one life, usually near its end. The trials found circumcision to be equally inefficient at preventing HIV, especially in the developed world where it is rare, but such calculations are seldom done by those determined to promote this peculiar operation. Pukerua Bay, New Zealand
Alzheimer’s puzzlement From Ian Clark In your article about using injections of an antiinflammatory to treat Alzheimer’s patients, Amgen www.newscientist.com
seems to think the reported rapid clinical response after the treatment – which neutralises tumour necrosis factor alpha (TNF-α) – doesn’t make sense (9 August, p 32). But this assumes that TNF-α acts in this disease only in its “traditional” role of causing inflammation, and takes no account of its recently realised function as a neurotransmitter. For example, at this year’s International Congress on Alzheimer’s Disease meeting in Chicago, a group of researchers from the US National Institute on Aging in Baltimore, Maryland, proposed an explanation for the reported rapid response in cognitive function. If investigated, rather than dismissed as implausible, puzzling clinical observations can drive basic research in useful directions, and become tomorrow’s accepted wisdom. Canberra, Australia
What doesn’t kill you… From Chris Chippendale You report the phenomenon of hormesis, in which small doses of a harmful substance are protective (9 August, p 36). Is this not an underlying principle of homeopathy, an idea constantly being criticised in your magazine? Sevenoaks, Kent, UK The editor writes: ● Hormesis and homeopathy are superficially similar but actually very different. The basic tenet of homeopathy is that illnesses can be cured with vanishingly small doses of substances that produce symptoms of the same illness in a healthy person. Hormesis, on the other hand, is the general beneficial effect of toxins at doses just below the toxic threshold. Hormetic agents have no beneficial effect at homeopathic doses. Perhaps more importantly, hormesis is established by scientific investigation whereas homeopathy is, to say the least, not.
Pronounce what?
converted into metal oxide fuel elements. Visit www.nuclearfaq. ca for more on CANDU. Bracebridge, Ontario, Canada
Natural plutonium
From Kevin Halford It was interesting to read of others sometimes being unsure of pronunciation (21 June, p 27). I am a distance-learning science undergraduate with the UK’s Open University. One tutor at an OU summer school, who had also taught in brick universities, commented that she could often tell brick students from distance learners: the former knew how to pronounce a word but didn’t know what it meant, while remote learners knew what a word meant but not how to pronounce it. Overpelt, Belgium
The CANDU can From Albert Eatock Your report on plans for a “Nuke in a box” (2 August, p 34) ignores the Canadian CANDU reactor design, on which the Indian reactor is based. CANDU can use natural uranium fuel, whereas light-water reactors use enriched fuel. It can also be refuelled while in operation. While Phil McKenna reports concerns that refuelling poses a proliferation danger – since it allows removal of plutoniumcontaining fuel elements – CANDU can burn up all the plutonium, producing used fuel that has very low levels of radiation compared with lightwater reactors. CANDU reactors are highly suitable for disposal of plutonium from degraded nuclear weapons, if it is first
From Gregg Brunskill You claimed that plutonium does not occur naturally (12 July, p 36). Small amounts of plutonium-239 are found in uranium ores – about 1 part in 1011 of uranium – and plutonium-244 has been detected in the spectrum of the sun. All nuclear-reactor fission nuclides have also been found in the Earth’s geological record, especially in the ancient natural reactor at Oklos in Gabon, as reported by François GauthierLafaye and colleagues in 1996 (Geochimica et Cosmochimica Acta, vol 60, p 4831). Alligator Creek, Queensland, Australia
Analogue/digital From Mike Edwards Bill de Mott and Feedback appear to be a bit literal-minded in querying what other kind of CDs can exist besides the “fully digital” (9 August). Most classical CDs are classed as follows: AAD, meaning digitally mastered from an analogue recording which was edited on an analogue system; ADD, digitally edited and mastered from an analogue recording; or DDD, fully digital. So the Best of Mozart CDs mentioned are modern digital recordings, not analogue recordings from the 50s or 60s remastered for the CD format. Worksop, Nottinghamshire, UK
Letters should be sent to: Letters to the Editor, New Scientist, 84 Theobald’s Road, London WC1X 8NS Fax: +44 (0) 20 7611 1280 Email: [email protected] Include your full postal address and telephone number, and a reference (issue, page number, title) to articles. We reserve the right to edit letters. Reed Business Information reserves the right to use any submissions sent to the letters column of New Scientist magazine, in any other format.
6 September 2008 | NewScientist | 25
interesting.” Then he goes into denial: “They cast no doubt whatsoever on the theory of the selfish gene.” Finally, he provides himself with an escape route by suggesting we replace the precise word “gene” with the vague “replicator”. We also learn that the job of a replicator is to “replicate accurately, the occasional mutation aside”. Well, thanks a lot, mate. Very illuminating. Shaftesbury, Dorset, UK
Cut! From Hugh Young, www.circumstitions.com The three trials of circumcision in Africa that were curtailed (19 July, p 40) suffered from other problems too. I calculate from the published results that more than twice as many circumcised men dropped out (327) – their HIV status unknown – as the number of non-circumcised men who were eventually found to have HIV (137). Trial participants were encouraged to be tested elsewhere, it being considered unethical to tell them the results found in the trial. To find you had HIV after a painful operation to prevent it would be a powerful inducement not to go back. Brian Morris is reported as claiming that circumcising 1000 baby boys will prevent one case of penile cancer. A fast surgeon may do 40 circumcisions in a day, so that’s 25 days’ surgery to prolong one life, usually near its end. The trials found circumcision to be equally inefficient at preventing HIV, especially in the developed world where it is rare, but such calculations are seldom done by those determined to promote this peculiar operation. Pukerua Bay, New Zealand
Alzheimer’s puzzlement From Ian Clark In your article about using injections of an antiinflammatory to treat Alzheimer’s patients, Amgen www.newscientist.com
seems to think the reported rapid clinical response after the treatment – which neutralises tumour necrosis factor alpha (TNF-α) – doesn’t make sense (9 August, p 32). But this assumes that TNF-α acts in this disease only in its “traditional” role of causing inflammation, and takes no account of its recently realised function as a neurotransmitter. For example, at this year’s International Congress on Alzheimer’s Disease meeting in Chicago, a group of researchers from the US National Institute on Aging in Baltimore, Maryland, proposed an explanation for the reported rapid response in cognitive function. If investigated, rather than dismissed as implausible, puzzling clinical observations can drive basic research in useful directions, and become tomorrow’s accepted wisdom. Canberra, Australia
What doesn’t kill you… From Chris Chippendale You report the phenomenon of hormesis, in which small doses of a harmful substance are protective (9 August, p 36). Is this not an underlying principle of homeopathy, an idea constantly being criticised in your magazine? Sevenoaks, Kent, UK The editor writes: ● Hormesis and homeopathy are superficially similar but actually very different. The basic tenet of homeopathy is that illnesses can be cured with vanishingly small doses of substances that produce symptoms of the same illness in a healthy person. Hormesis, on the other hand, is the general beneficial effect of toxins at doses just below the toxic threshold. Hormetic agents have no beneficial effect at homeopathic doses. Perhaps more importantly, hormesis is established by scientific investigation whereas homeopathy is, to say the least, not.
Pronounce what?
converted into metal oxide fuel elements. Visit www.nuclearfaq. ca for more on CANDU. Bracebridge, Ontario, Canada
Natural plutonium
From Kevin Halford It was interesting to read of others sometimes being unsure of pronunciation (21 June, p 27). I am a distance-learning science undergraduate with the UK’s Open University. One tutor at an OU summer school, who had also taught in brick universities, commented that she could often tell brick students from distance learners: the former knew how to pronounce a word but didn’t know what it meant, while remote learners knew what a word meant but not how to pronounce it. Overpelt, Belgium
The CANDU can From Albert Eatock Your report on plans for a “Nuke in a box” (2 August, p 34) ignores the Canadian CANDU reactor design, on which the Indian reactor is based. CANDU can use natural uranium fuel, whereas light-water reactors use enriched fuel. It can also be refuelled while in operation. While Phil McKenna reports concerns that refuelling poses a proliferation danger – since it allows removal of plutoniumcontaining fuel elements – CANDU can burn up all the plutonium, producing used fuel that has very low levels of radiation compared with lightwater reactors. CANDU reactors are highly suitable for disposal of plutonium from degraded nuclear weapons, if it is first
From Gregg Brunskill You claimed that plutonium does not occur naturally (12 July, p 36). Small amounts of plutonium-239 are found in uranium ores – about 1 part in 1011 of uranium – and plutonium-244 has been detected in the spectrum of the sun. All nuclear-reactor fission nuclides have also been found in the Earth’s geological record, especially in the ancient natural reactor at Oklos in Gabon, as reported by François GauthierLafaye and colleagues in 1996 (Geochimica et Cosmochimica Acta, vol 60, p 4831). Alligator Creek, Queensland, Australia
Analogue/digital From Mike Edwards Bill de Mott and Feedback appear to be a bit literal-minded in querying what other kind of CDs can exist besides the “fully digital” (9 August). Most classical CDs are classed as follows: AAD, meaning digitally mastered from an analogue recording which was edited on an analogue system; ADD, digitally edited and mastered from an analogue recording; or DDD, fully digital. So the Best of Mozart CDs mentioned are modern digital recordings, not analogue recordings from the 50s or 60s remastered for the CD format. Worksop, Nottinghamshire, UK
Letters should be sent to: Letters to the Editor, New Scientist, 84 Theobald’s Road, London WC1X 8NS Fax: +44 (0) 20 7611 1280 Email: [email protected] Include your full postal address and telephone number, and a reference (issue, page number, title) to articles. We reserve the right to edit letters. Reed Business Information reserves the right to use any submissions sent to the letters column of New Scientist magazine, in any other format.
6 September 2008 | NewScientist | 25