For the record
The burying of time capsules may not be unique to the 20th Century (Comment, 18 February). During recent building work a time capsule in the form of a glass jar was discovered behind the foundation stone of Caterham School’s Victorian swimming pool. The pool was opened in 1889 by the Lord Mayor of London and believed to be among the first covered heated pools owned by a school.
The glass jar was placed in such a way that it could only have been discovered by the removal of a foundation stone. Among the artefacts inside was an architect’s drawing of the pool and a contemporary school badge.
The express intention of communicating with future generations may not seem so special when you consider examples other than time capsules for instance wills, portraits (painted or photographic), statues, or even gravestones. The idea of a permanent record of oneself or one’s achievements is appealing to the human psyche. Perhaps the most bizarre example is found in the embalmed body of the 19th-century philosopher Jeremy Bentham.
What sets apart time capsules is that they often deal with the mundane aspects of everyday life. The selection of items for burial can be a fascinating activity for schoolchildren; I suspect the process of choosing items is a more valuable learning exercise than a future generation examining the contents of a time capsule, especially considering that other 20th century obsession: record keeping.
Vaccine viruses
Although Helen Saul provides an interesting overview of alternatives to inactivated subunit vaccines used in Western countries (“Flu vaccines wanted: dead or alive”, 18 February), some statements relating to live attenuated vaccines require further clarification.
Cold-adapted (ca) live vaccines have been delivered experimentally to thousands of volunteers of many ages in the US and annually to millions of children in Russia. As the article indicates, vaccine viruses have been shown to be extremely well tolerated, are genetically stable and do not appear to be transmissible between humans. Stability is conferred by lesions in several of the 6 internal genes that are common to each vaccine subtype, which can be identified by molecular techniques within days. It is a requirement within Russia that each new vaccine be tested in a small number of seronegative volunteers before release; such a requirement (currently unenforced) forms part of EC regulations for the release of subunit vaccines.
The statement “Live vaccines work best against a single strain” is true only of US ca vaccines. Russian vaccines are trivalent and the concentrations of component viruses have been adjusted to produce satisfactory responses to each strain in both children and adults. Live vaccines are a particularly attractive option for the immunization of children who, in Western countries are largely unprotected yet remain a significant focus of infection and would be particularly vulnerable at the time of a pandemic.
Live US ca vaccines were shown to provide less than full protection when administered as a single dose to the elderly. Recent evidence, again from Russia, indicates that (1) satisfactory responses are produced in the elderly using ca vaccines that are more immunogenic than those used in children, and (2) optimum responses in both children and the elderly are produced by a second dose. In other words, with live vaccines, it is possible to boost immunity to influenza incrementally in the respiratory tract, something that is not possible with subunit vaccine. There is no US equivalent of the more immunogenic vaccines designed for use in the elderly in Russia.
Attempts to develop live vaccines by reverse genetics may eventually produce an effective vaccine but the final product may be no more attenuated nor genetically stable than ca vaccines. DNA vaccines, despite recent excitement (and setting aside regulatory minefields likely to impede their registration) will essentially provide similar immunity to influenza to that obtained with current subunit vaccines without the benefits of direct mucosal stimulation afforded by replicating viruses. Parenterally administered vaccines have a fairly poor track record in the prevention of infectious diseases at mucosal surfaces in both humans and animals.
Killer pens
A year or so ago New 杏吧原创 raised the topic of children in Britain dying by suffocation after swallowing the caps of popular, low cost pens (This Week, 8 January 1994). Children who swallowed those caps could not breathe and although rushed to hospitals were not able to make it. The cap of the “killer pen” was sealed at the outward end.
You reported that an international standard had been agreed to make the pens safer. This stated that a hole should be drilled in the end of the cap. If the cap got lodged in a child’s throat, the hole allowed the child to breathe while it was taken to hospital for the cap to be extracted. It was expected that all pens produced from then on would have this hole in the cap.
I have been waiting for that to happen ever since the article came up in the New 杏吧原创. However, it has not happened here in Colombia, South America, where “killer pens” are still sold by the millions. How many of our children must have died of suffocation because the safety measure has not been incorporated to the pens sold here 鈥� and perhaps in other parts of the developing world?
It is outrageous that the big overseas companies who sell us these things can so overlook the safety of their third world consumers.
Cathedrals in space?
In his article “Space mission impossible?” (25 February), Larry Krumenaker suggests that scientists sending a probe to Alpha Centauri will want to see results from their endeavours, limiting the project to 40 years.
No doubt scientists feel like that, but this ignores the altruistic nature of science 鈥� working for the benefit of humanity. Could not scientists derive satisfaction from beginning something that others will complete? After all, medieval cathedrals took generations to build. Craftsmen beginning the project knew that neither they nor their children would see the building completed.
Also 鈥� what about scientists nearing retirement who help to send the probe on its way? They will know that they will not see the data from Alpha Centauri, but they may gain satisfaction from playing a part in the furtherance of human knowledge.
Problem cities
Many of the anticar faction in the correspondence on the subject of the efficiency or otherwise of cars give addresses in or close to urban conurbations, and can therefore be expected to take the urban viewpoint (Letters, 11 February and 11 March).
The railway was originally developed to move large quantities of ore in mines, and later to move raw supplies into ironworks. Only as an afterthought were trains used to move people, after the Industrial Revolution turned humans into a bulk commodity. All fixed track transport systems are inflexible, and can only operate successfully where there can be economies of scale. The railway may use energy slightly more efficiently than the internal combustion engine, but the car only moves at all when there is at least one occupant, whereas trains must spend a considerable amount of time running empty, or nearly so.
For general personnel transport, the car is nearly perfect. It gives levels of comfort, convenience and security which can never be matched by any mass transport system, and only uses energy and emits pollution when actually required.
The problem is not with the car; it is with the city, and more particularly with the insane concept of commuting. While there is a case to be made for separating chemical works and steel mills from human accommodation, there can be no sense whatever in making people live in huge housing estates which they have to leave to go to work in outwardly identical office blocks grouped together for no good reason in the centres of major cities.
The average commuter appears to spend about two hours each day “struggling” to and from work through a herd of others, only to get into the office, hang up a coat, sit down, switch on a computer and pick up a telephone. Why travel? You could do that in the Orkneys.
Their constant whining about the dirtiness of the trains (who dirtied them?), their lateness (would they really like them to be early?) and expense sicken those of us who are expected to pay taxes to subsidise their travel to a city so that they can earn more money.
The only practical way to solve transport problems is to remove the need for so much unnecessary travel, so that urban dwellers will not need cars except for occasional trips out of towns, when it is much more cost-effective to hire a car. Let people work where they live or live where they work.
Same old claim
It was most interesting to read that Monsanto proposes “to genetically engineer cotton 鈥� to contain both Bt genes and the cholesterol oxidase gene” in order to control both caterpillar pests and boll weevil (This Week, 4 March). According to a representative of the company, “It is highly unlikely 鈥� that an insect could develop resistance to both types of insecticidal genes at the same time.”
Have we not heard this before? Similar claims have been made over the last forty years or so for mixtures of insecticides, of fungicides and of antibiotics with different modes of action. Identical claims have also been made for incorporating many disease resistance genes into cultivated crops (“pyramid” varieties).
The evidence from most of these applications is that the target pests and pathogens have little more difficulty in overcoming such combinations than they do in overcoming the individual control agents. We already know from both agriculture and laboratory experiments that target species can evolve resistance to Bt toxin.
It is completely understandable that a commercial organisation will want to promote the advantages of its products, but can it really be that a company at the cutting edge of technology has to rely on such a naive and largely discredited argument to justify its product? Do the researchers never read the relevant literature?
Letters to the Editor
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Sensitive issue
The article “Life in the tissue factory” (11 March) raises an interesting question. As the tissue is grown from foreskins, does it respond in the normal way when fondled or licked?
Doubling up
Richard West (Letters, 11 March) gives 108 possible meanings to the sentence, “When John met his uncle in the street he took off his hat”. This number can easily be doubled: “uncle” can mean either “mother’s brother” or “father’s brother”.
Quasi quasers
Quasars must be very distant because of their enormous red shift. For us to be able to see them at all at such distances they must also have great sources of power, faint though they are. And, because they are so distant we are seeing them young, so their spectral lines don’t evince a lot in the way of heavy elements.
Now the best theory about their power source (that they comprise juvenile galaxies falling into biggish black holes) has been shot by the Hubble telescope: lots of quasars don’t have galaxies near them (New 杏吧原创, Science, 21 January).
Imagine (and I wish I had some green ink in which to pen this) a number of spacecraft moving about our own galaxy. Further imagine that these are fusion-powered by an efficient drive that is one that only emits appreciable amounts of radiation directly aft.
We would only be able to see the ones that, by chance, happened to be moving directly away from us. They would exhibit no tangential motion. They would be very faint. They would have enormous red shifts. And they would only display the spectra of light elements. In fact, they would look exactly like qua 鈥�
Well done, chaps
Good to see the bulldog spirit surviving in our premier research establishments.
Bruce Joyce of Imperial College suggests that because we in Britain spend less on semiconductor research than they do in Japan, we think harder about what we do and waste less (“Japan heads for quantum country”, 4 March).
That’s OK then, chaps. Despite the British-owned semiconductor industry being several orders of magnitude smaller than that of Japan, we can at least think that we are superior.
Dino doubt
In Inside Science no. 80 (18 March), Pete Moore stated: “鈥� dinosaurs, such as Dimetrodon 鈥� “. However, Dimetrodon was not a dinosaur but was a pelycosaur living much earlier.
Bottle of teardrops
As you indicated in your article, the mechanisms producing compression and tension zones in force-cooled glass are well-known (“Why do teardrops explode?”, 11 February and Letters, 11 March).
In the mid-1960s when I was an undergraduate in the Department of Metallurgy at Sheffield University, we were obliged to attend lectures on a Saturday morning at the Department of Glass Technology. This gross and traumatic imposition was, however, enlivened by some excellent demonstrations.
One of particular note, reflecting a larger version of Prince Rupert’s drops, involved a standard milk bottle which had been heated in a furnace and then air cooled on the outer surface.
The lecturer, who may even have been the Professor of Glass Technology, hammered a nail into a piece of wood with the milk bottle. He then put a nail into the milk bottle, in contact with the tension zone of the inner surface, shook it about and the milk bottle shattered into numerous fragments.
Sensitive Hitler
Claire Weeks’s assertion that Hitler was not a vegetarian (Letters, 11 February) is at variance with the account of Hitler’s eating habits given by his secretary, who dined with him frequently over a number of years during the war. She records that on one occasion he rebuked his guests for eating meat, saying that had they seen animals being slaughtered, as he had, they would not eat meat.
No nude Bill
Your “In Brief” note (4 February) indicates a misunderstanding of which group of students the nude “posture” photographs were taken. Only entering undergraduates were photographed, so Bill and Hillary Clinton were not photographed at Yale when they entered the Yale Law School. Hillary Rodham, rather, had been photographed when she entered Wellesley several years earlier.
Singular two
Kurt Kleiner rightly highlights the desperately high attrition rate among the world’s languages (This Week, March 4) but I suspect that the majority of conservationists will have read the article with merely passing interest. This is likely to be particularly so in Australia, which has one of the most highly developed conservation lobbies in the world (and all strength to their elbows!).
However, Australia is also a treasure-trove of human culture with some 90 extant indigenous languages (out of 250 at the time of European settlement), only 20 of which can be said to be healthy. If that rate of loss (and endangerment) were paralleled in plant and animal species, would we not hear something of a song-and-dance about it?
I also noted Kleiner’s comment that languages commonly make the binary distinction between “one” and “more than one”. This simply illustrates what many people have alleged 鈥� that we Scots are a strange bunch. In our native Gaelic (also, I might add, struggling against the onslaught of a major language) the plural form is not reached until the number three; thus “one book, two books, three books 鈥�” “is “aona leabhar, d脿 leabhar, tri leabhraichean 鈥�” As the linguists said, diversity is a fine thing.
Winning school
From our Forum piece “Counting the cost of inadequate maths” (4 March) we inadvertently omitted the fact that our survey of sixth form opinion was a competition: a prize of 拢100 was offered to the school giving the best presentation and analysis of the data it collected, and was won by Bury Grammar School for Girls. The sad demise of Mathematics Review prevented us from announcing this result in its pages, so I would be very grateful if you would announce it here.
Saying v signing
The first sentence of Rosie Mestel’s article on the acquisition of language by deaf children (This Week, 25 February) stated that: “Profoundly deaf children must be exposed to sign language as early as possible.” This gives the impression that sign language is the only possible alternative. She should have added: “or must be exposed to speech, lip reading and amplification of residual hearing as soon as possible”. (Almost all profoundly deaf children have useful residual hearing for low frequencies).
Early detection of hearing impairment in children was part and parcel of work in audiology for many decades. It certainly was one of my preoccupations in audiological research during more than three decades. Our experience showed that when severe hearing loss was detected early, deaf children who had no other disabilities learned phonetically based language and developed a good ability to communicate by speech. The advantages of an ability to communicate by speech cannot be doubted.
The pro-signing and pro-speech dispute in this country flared up again (as many times before) following the theatre play Children of a Lesser God in 1992, which showed how a young deaf woman resisted learning to speak and how successful she was with sign language. Many people were persuaded that sign language was the only right way for the deaf.
A year later it was reported that Elizabeth Quinn, the deaf actress, had decided that speech was, after all the best way. She trained for a year, perfected what speech she had and declared: “I decided I would no longer be lonely 鈥� hide behind sign language 鈥� Now I do things I’ve never done before 鈥�
No dogmatic approach is acceptable. For some deaf children sign language is appropriate but for many others speech is best. It depends on a number of circumstances and proper assessment of what is the most appropriate method for each child.
Thin air
D. D. Drysdale suggests that if spacecraft were filled with an atmosphere containing only 12 per cent oxygen, this would not support combustion and therefore avoid all the problems associated with tackling fires in space (Letters, 4 March). However, diluting the atmosphere with nitrogen would reduce the partial pressure of oxygen to approximately 12 kilopascals, and because he thought this low oxygen tension was incompatible with life, he suggested pressurising the spacecraft cabin to 1.7 bar to compensate for this.
In fact, breathing air with an oxygen partial pressure of 12 kPa causes relatively few problems, as anybody who lives in, or visits, mountainous areas above 4000 metres can testify (as a guide, Mont Blanc is 4800 metres high). Even if the astronauts were to engage in activities as vigorous as climbing or skiing, the hazards associated with hypoxia in a 12 per cent oxygen atmosphere should be minimal. Sudden exposure could induce Acute Mountain Sickness (headache, nausea, weakness), but a week’s skiing holiday at high altitude before venturing into space should be sufficient to allow acclimatisation.
With regard to the problems of fire onboard the Shuttle and other space-going craft, there is a system available for combine harvesters and other plant with multiple sites for likely combustion, which it seems to me might be of some use.
It consists of a pressurised cylinder of extinguishant attached to plastic tubing going to or through any area deemed to be at risk. When the temperature at any point rises sufficiently to weaken the tubing, it ruptures and releases the extinguishing agent right at the core of the problem, possibly before any smoke has been generated, let alone detected.
Suitably modified, perhaps with the tube incorporated within the wiring harnesses, and with the addition of a marker dye to enable easy identification of the site of the fire, this would appear to overcome most of the problems mentioned in your article on the subject.
If so, it would make a pleasant change for benefit to go from agriculture to the space industry 鈥� perhaps a case of plough shares being turned into spacespares?