Letters : Handling conflict
Geneva
Nick Robins and Charlie Pye-Smith state that “there is a feeling that existing institutions within the UN family are ill-equipped to deal with environment security issues” (“The ecology of violence”, 8 March, p 12).
This is certainly contradicted in the ECE (UN Economic Commission for Europe) region. Among the existing legal instruments, the ECE environmental conventions, including the Convention on the Protection and the Use of Transboundary Watercourses and International Lakes, are advanced examples of how conflict prevention and dispute settlements are integrated with environmental objectives.
This convention is preventive by design, and contains a number of instruments of conflict prevention: obligation to cooperate on the basis of equality and reciprocity; joint monitoring and assessment; exchange of information between riparian parties; warning and alarm systems; mutual assistance; informing the public; responsibility and liability; and joint bodies for the catchment areas. It also contains instruments for the settlement of disputes, such as detailed arbitration procedures.
The most recent offspring of the ECE water convention will be the Danube River Protection Convention, presently in an advanced stage of preparation by the riparian states of the Danube catchment area.
Letters : Vacuum welding
Moulsford, Oxfordshire
Philip Chien states that arc welding in the vacuum of space is impossible (“There’s a hole in my spacecraft”, 19 April, p 42). This is not so. I published a paper almost forty years ago (British Journal of Applied Physics, vol 9, p 488) based on work done at the Metropolitan-Vickers Electrical Company, describing a method of stabilising an arc discharge in vacuum using shaped magnetic fields. The field confined the electron emission sites, the cathode spots, to a small area of a cold cathode, and confined the arc column so that the energy density at the anode was high enough to melt it.
Several welds were made in a vacuum chamber and the method could have been perfected had anyone been interested at the time. It is potentially a much simpler and cheaper method than the hand-held electron gun described in the article.
Perhaps NASA could have saved a lot of money by searching the old literature.
Letters : Vacuum welding
Lancaster
Chien explains that there is no gas in space for a welding arc to ionise, but this fact does not adequately explain why astronauts must use electron beam welding to repair their space craft.
At higher voltages, the end of a conventional welding rod or wire vaporises, rather than melts, and “MIG” welding shrouds the arc in a flow of inert gas to protect the weld from oxidation. Either will provide ionisable vapour or gas molecules, even in space.
However, arc welding of any sort spatters droplets of red-hot metal that readily burn through clothing and would not be healthy near a spacesuit. Is this not the more prosaic reason for choosing electron beam welding?
Letters : Modem crashers
Birmingham
You state that old computers would not be able to handle the speed of new modems that run at up to 10 megabits per second (Technology, 26 April, p 24). I found this to be odd, as the computer I am writing this e-mail on has only a 486DX33 chip but quite happily accepts data from the Internet on its network card (that runs at 10 Mbps), and is connected to a very large link to the Internet (via SuperJanet).
I have used this link at odd times of the day when the level of traffic on the LAN is very low and have been able to download very large files in only a short time. The computer has never crashed. I am sure that if accepting data at 10 Mbps was a problem, then all those computers sat on LANs around the world would crash quite frequently鈥攐r is this just another way to get you to upgrade to a newer computer?
Mark Ward writes: There are a number of reasons why Neil Ambrose’s PC may not crash. First, if there is a high-speed connection such as SuperJanet nearby then the card linking PC to network will probably be configured for these rates by having enough memory on board to cache data so it is passed on in manageable chunks.
Second, the office networks never pass on data at their maximum rate. An Ethernet network can pass data on at 10 Mbps, but it is so bad at sharing bandwidth that people rarely get more than a couple of megabits per second.
Third, downloading files and watching videos are very different things. Files usually go straight onto a hard disc. The connection between the disc and network is nearly the fastest inside the computer. The connection between network and screen is much slower because so much interpretation is involved.
Letters : Caring and cloning
Roslin, Edinburgh
The real potential for the nuclear transfer technique in transgenics, now that we have shown it can be accomplished using a variety of cells, is in genetically modifying the cells and then selecting those where the required precise genetic modification has occurred.
These cells can be used to produce a small clone of founder generation transgenic animals, thereby using less animals overall, and transferring the selection process from animals to cells鈥攕urely a positive animal welfare benefit (“Suffering of the lambs”, 26 April, p 16). Thereafter, sheep would be bred conventionally.
However, the main thrust of your article concerns a supposed lack of regulation of transgenic animals (“legal and ethical free fall”, according to one lawyer) and a fear that there might be some long-term damaging effects due to the foreign gene.
In Britain, all work is governed by the Animals (Scientific Procedures) Act 1986. This requires us to carry out risk assessments which balance any harm to the animals against the expected benefits to mankind on each new procedure and each new gene we wish to introduce.
The health of our transgenic animals is rigorously monitored by PPL’s three qualified vets who provide 24-hour, 7-day-a-week cover. Our procedures and the welfare of our animals are independently audited by the Home Office, whose inspector makes several announced and unannounced visits in each year. Bob Combes and Caren Broadhead are welcome to do the same if they want to see how the legislation works in practice.
Those arguing against commercial use of genetic modification invariably cite the problems with the Beltsville pigs as evidence of the unacceptability of the technology, but the fact that this work was published 12 years ago suggests that there are no more recent examples which support their arguments.
Letters : . . .
We studied in detail the behaviour of 50 crossbred lambs carrying a human transgene (human alpha-1 antitryspin), compared with 50 controls from the same flock which had been reared and housed under similar conditions. There were minor differences in resting behaviour, but these were inconsistent when the animals were housed indoors in pens rather than outside on pasture, suggesting they were of little importance.
There were also some effects on competitive behaviour鈥攖he transgenic lambs were less aggressive when feeding鈥� but this might have been because they had been handled more.
There was no evidence that this particular transgene had any harmful effects on the lambs. It needs to be further monitored in large populations of animals of all types and ages, but it does seem that not all genetic modification causes problem for animal welfare.
The techniques of behavioural observation used are sensitive and, provided sample sizes are adequate, can pick up small differences between groups. They would be suitable for future monitoring of the welfare effects of other transgenes.
Letters : Tasteless spuds
Lancaster
By concentrating exclusively on potatoes’ disease resistance and yields鈥攁nd ignoring their flavour and texture鈥擣red Pearce illuminates a major problem in late 20th-century agriculture: the almost total disconnection of cook and scientist (“The famine fungus”, 26 April, p 32).
As any cook knows, potatoes differ enormously in their taste and culinary qualities, even though they may look exactly the same. There are varieties that become crisp and golden when roasted or fried, varieties suitable for baking, salad potatoes and鈥攂ecoming increasingly prevalent, unfortunately鈥攖hose varieties that the late Potato Marketing Board used to advertise as “general purpose”, in other words good for nothing.
One has an uneasy feeling that the breeders are successfully developing new varieties of superbly disease resistant, heavy cropping, “general purpose” potatoes. If not, what particular usages are they being designed for?
Letters : . . .
York
Pearce states that “the potato is the best package of nutrition in the world”. I have used his figures on yield together with figures for the energy and protein content of potatoes, rice and wheat which I took from a data book.
As I expected, rice has the highest yield in terms of energy (18 per cent more than potatoes), but the lowest for protein. Wheat is about 8 per cent lower in energy per hectare than potatoes, and almost exactly the same for protein.
Given the enormous variation in world values of crop yield per hectare, surely the differences between potatoes and wheat are insignificant. The relative value of rice and potatoes depends on whether energy or protein is the limiting nutrient in a diet.
Letters : The God gene
Warrington, Cheshire
D. W. Dew may be interested to learn that the neurological and genetic basis for religious beliefs have received some attention (Letters, 26 April, p 52). It has long been known that certain neurological disorders (such as temporal lobe epilepsy) can cause hyper-religiosity. The visions of St Paul, Mohammed, Joan of Arc and others come to mind.
As for genetics, researchers at the University of Minnesota, studying identical twins raised apart, have shown that if one twin is deeply religious the other often is too. They conclude that religious belief is about 50 per cent genetic (Waller et al., Psychological Science, 1990, vol 1, p 138).
This says nothing about the truthfulness or logic of religions, but the huge numbers of people with this genetic disposition does indicate that the gene(s) involved had a selective advantage in the past.
Finally, irrational beliefs are not entirely independent of intelligence and education. A review by B. P. Beckwith in Free Inquiry (vol 6, p 46, 1986) looked at all the relevant studies conducted up to that time in the US. Of 43 studies, four found no relationship between religious belief on the one hand and intelligence and education on the other. The remaining 39 studies consistently found an inverse relationship.
In other words, the more intelligent and educated a person is, the less likely that person is (on average) to be religious.
Letters : The whole truth
California
Graham Farmelo’s review of The Whole Shebang leaves me with no great grounds for complaint, but perhaps I may be permitted a comment about his concern over the question of whether my defence of the big bang theory means that I have “gone native”, and become “too reverential” toward cosmological orthodoxy (Review, 19 April, p 46).
One’s job as a science writer, it seems to me, is to call things as one sees them, based upon as clear and informed a perspective as years of thought and thoroughgoing research can afford.
I agree that one should “provide a critical perspective”, as Farmelo aptly puts it. But the fact that one may reach an orthodox conclusion does not in itself mean that one has been insufficiently critical. Contrariety in itself provides no golden key to the truth.
Was I being radical or orthodox when, twenty years ago, I was attacked by many astronomers for asserting that quasars are the nuclei of young galaxies?
I don’t really know. What I do know, and care most about, is that I was right. And that would seem to be a reasonable basis upon which to judge The Whole Shebang, now and in the future.
Letters : Sleep service
Those of us who turn on the BBC World Service when we wake up in the night have known for a long time that a radio (placed close to the ear so as not to wake others) is the best way to promote a return to sleep (“Calling all insomniacs…”, Mind Travellers supplement, 26 April, p 2).
The results of Boris Pasche’s experiments on insomnia with low energy radio waves now confirm our intuitive observation. Up to now we probably thought that it was the BBC foreign correspondent’s account of the political situation in Outer Mongolia which sent us back to sleep, but it seems that it may be the radio waves which are having the required effect.
Dale Serjeantson
University of Southampton
Can you clear up a confusion in the article on radio waves and sleep? It refers at one point to “VHF waves below about 50 Hz” and “15 Hz radio waves”. Electromagnetic waves of these frequencies can exist but would have wavelengths measured in thousands of kilometres.
It seems more likely that these are the frequencies with which the radio waves are modulated.
D. A. Simmons
Cambridge
This is quite right. As the article states, the radio waves in question are amplitude modulated. The numbers given in the text refer to the modulation frequencies. The carrier wave wasn’t specified in the article, but is 27.12 MHz鈥擡d
Letters : Curb the cars
Uxbridge
Douglas Stewart confirms what common sense tells us, that reducing car speeds in urban areas reduces accidents (Letters, 12 April, p 50). But will anyone take any notice?
The fault lies with the car manufacturers. They are bent on enabling cars to travel faster and give people a more comfortable drive. No consideration is given to what is appropriate for built-up areas.
Those designing cars should concentrate on developing an override device with the intention of controlling speed. Only a mandatory requirement for using such a system will stop drivers exceeding the speed limit.
The past three cars I have bought, all the same model, have seen maximum speeds rise from 90 to 115 miles per hour over seven years, with miles per gallon dropping from 45 to between 29 and 33 in the present one.
Not only are there more cars on the roads but each is using, on average, more fuel for a performance that is totally unsuitable for roads used by pedestrians.
We are living in the age of the two-fingers-to-you mentality of the impatient speedster. The potential to outpace the other person and blast off from 0 to 60 in 9 seconds must be curbed. Make the car so that it is not wholly designed to fulfil the whim of the driver.