Cold clue
The hypothesis that there could be a connection between certain lineages of mitochondrial DNA and susceptibility to Alzheimer’s disease should be easy to put to the test (17 January, p 12).
If the increased ability of some mitochondria to generate heat makes Alzheimer’s less likely to appear, family studies should show some degree of inheritance of the disease through the female line. Moreover, people exhibit a vast range of different reactions to the cold, as is shown by the battles in homes and workplaces over open windows. One could ask the relatives of people suffering from Alzheimer’s how well those people have coped with the cold: the hypothesis would suggest that you would find an excess of individuals who are not well-adapted to the cold among patients with the disease.
Resistance is fertile
Elias Zerhouni, the head of the US National Institutes of Health, refers to his partnership with Bill Gates (10 January, p 46), and later in the interview says: “Medical research is in dire need of transformation鈥t’s not working鈥e don’t even have a common informatics. Can you imagine running the internet with seven different browsers and having 10 Microsoft companies out there, each one selling a different product?”
The idea that alternative browsers are a bad thing will surprise users of Mozilla, Opera, Firebird, Netscape, Camino, Arachne, Konqueror and the many other browsers 鈥� from more than 10 companies 鈥� that flourish despite Microsoft’s attempt to undermine the web standards that allow them all to compete. Instead of railing against software choice, Zerhouni should realise that “partnership” with Microsoft often becomes assimilation, and choice is part of the “American way” he so much admires.
Double the hum
Commenting on my feature, “Mingle bells” (13 December, p 40), Godfrey Dack points out that the wavelength of the fundamental vibration of a stretched string is equal not to its length but to twice its length (24 January, p 29). He is quite right. The confusion arises because a different nomenclature is used for bells and string. For a bell, the lowest-frequency harmonic is called the hum, and the so-called fundamental has double the frequency of the hum. Presumably, the dynamics of the vibrating bell are such that the first overtone turns out to be far more audible than the hum 鈥� so that’s the pitch we tend to assign to the bell and call the fundamental.
Slow pole
As the tip of Lee Baxter’s pole (31 January, p 39) approached the speed of light, its mass would approach infinity, as would the force required to accelerate it further. So sorry Lee, no cigar.
Victorian spots
It is possible to go further back than Barry Horne’s citation of 1937 as a date when writers noted financial markets moving with sunspot cycles (24 January, p 29). I think it was the economist W. S. Jevons who first wrote, in around 1875, that grain market and other financial market prices moved in line with sunspot cycles.
Canine landers
I have a theory as to why both Beagle and Rover failed: there are no trees on Mars to pee on.
Burn your own tail
As a possibly tetrachromatic woman, I was fascinated by that section of Richard Hollingham’s article “In the realm of your senses” (31 January, p 40).
But the next paragraph brought me up short and made me question what right we have to conduct the research that brought me this information. “Meanwhile, at McGill University in Montreal, Canada, mice are having their tails dipped in hot water to study their reaction to pain.”
Forget tetrachromism, I thought furiously, forget pain research. If you want to discover how much it hurts to get your bum burnt, go and stick your own tails in hot water.
If scientists are angry and confused at the public response to the University of Cambridge’s proposed primate research centre, they need look no further for explanation. Until scientists accept that animals feel pain, and until scientists are willing to deny themselves relatively trivial research projects 鈥� which, in the grand scheme of things, the variation in sense reactions surely is 鈥� in order to save animals pain, there will continue to be protests when they try to expand their research.
So I was comforted to read the next paragraph down: “Bob Coghill of Wake Forest University, North Carolina, took 17 [human] volunteers and applied a heat source to the backs of their calves鈥�” I hope he remembered to dip their calves in freezing water straight afterwards, and that he paid them handsomely.
Airgun gauntlet
The presumption mentioned in Tam Dalyell’s column that acoustic pingers may be employed to discourage cetaceans from approaching the airguns used in seismic surveys is very dangerous, since it offers the offshore industry yet another excuse to continue using these devices (24 January, p 45).
Airgun arrays, which are the most common energy source used in seismic surveying, discharge every 7 seconds. They operate hour upon hour, day upon day, for a season that lasts at least six months. The energy released per discharge by the airgun array is vastly greater than that produced by a pinger. It has to be 鈥� the job of the airgun is to whack sound energy many kilometres through the Earth’s crust and back again, and was previously done with dynamite. In energy terms, such arrays “dynamite” everything in their vicinity.
From observation and underwater recordings we know that airgun arrays do not discourage cetaceans from approaching. We, and others, have recordings taken during seismic surveys in which, intermingled with the airgun detonations, dolphins and killer whales can be heard calling. This means they had to be close to the survey. So I pose the question: why should pingers keep them away?
Assertions that pingers will “alert” the cetaceans to danger are most unfortunate, since they carry with them the assumption that cetaceans have a human awareness of what is happening to them. We can read the health warning on the packet, yet no small number of us still smoke. Cetaceans never get to see the packet, let alone read and understand the health warning.
Trees are no answer
Max Trevitt’s letter on the use of trees for scrubbing carbon dioxide is wrong, surely (31 January, p 38). The amount of CO2 released by a dead tree when it decays is equal to the amount it absorbs when alive. So trees just provide short-term sequestration, and any long-term effect would have to derive from a sustained rate of planting far in excess of the rate of tree death, which is not realistic.
Wild fish win out
Your editorial of 17 January is on solid ground castigating the salmon farming industry, but like your letter-writer Rowan McCartney (31 January, p 38), you fail to differentiate your omega-3 polyunsaturated fatty acids adequately.
Wild salmon and wild fish in general remain the best bet, not only for lower levels of contaminants but also for nutritional benefits. While other omega-3s with fewer carbon molecules, principally alpha-linolenic acid (ALA), are abundant in linseed and flaxseed oils, as McCartney points out, only a marine-based diet will yield significant amounts of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
It is on DHA and EPA that research into health benefits has focused. ALA appears to function as a substitute in the absence of DHA and EPA, and may be converted into them at very low levels. The matter of synthetic isomer DHA is still speculative, and the same health benefits have not yet been demonstrated.
Wild fish and algae remain the best sources of DHA and EPA. Farmed fish can indeed be given feed derived from wild fish to duplicate this, but as the industry increases the amount of grain derivatives in feed in an effort to reduce costs, the levels of DHA and EPA decrease, with a corresponding rise in less beneficial omega-6 fatty acids.
Given the unique nutritional benefits to be derived from wild fish in our diets, there is all the more reason to manage our oceans sustainably, rather than converting them into industrial feedlots.
No GM surrender
Germany’s introduction of a bill to allow the import, cultivation and sale of genetically modified organisms and products derived from or containing them does not in any way represent a “weakening” of Europe’s “relentless opposition” to this technology (24 January, p 4).
The European Commission, Parliament and Council of Ministers have spent the last four years hammering out a series of compromises between the different strands of opinion on the issue, resulting in a body of law which all member states are obliged to transpose into their own legislation. This is all Germany is doing.
Directive 2001/18 on the deliberate release of GMOs, two regulations governing labelling and traceability and the quality of GM food and feed, and a measure to bring EU law into line with the Cartagena Biosafety Protocol are all now in place. All will necessitate changes to the laws of member states.
There is a balance of forces around this issue, with all the money on one side and public opinion largely on the other. The compromise at EU level was eventually accepted by both sides because we each believe it will serve our cause. The multinationals will be free to import their products, but these products will have to be labelled. Because of this, no one will buy them, food retailers will reject them, and the multinationals will have to look elsewhere to unload the unwanted products of their enormous mistaken investment.