Letters: Suspect soya
The article ‘Cancer – is soya the solution?’ (9 July) fails to do justice
to matters which were discussed more than a decade ago. In the late 1970s
my colleagues and I found that raw soya flour, comprising as little as
5 per cent of the diet, produced pancreatic cancer in 5 to 10 per cent of
the rats fed the diet. Rats do not develop pancreatic acinar cancer spontaneously.
These findings were of such concern to the industry that the US Department
of Agriculture repeated the studies and confirmed the findings. We also
found that when a pancreatic genotoxic carcinogen was coadministered to
the rats, in amounts insufficient to produce pancreatic cancer, the combined
effects of the carcinogen and the soybean diet produced pancreatic cancer
in 60 per cent of the animals. Subsequent studies were scheduled by the
Food and Drug Administration but were cancelled.
At the same time, Walter Troll in New York pointed out that protease
inhibitors might be useful in inhibiting carcinogenesis in many organs.
The relevance to man of these findings has not been satisfactorily studied,
although it is obviously potentially very important. If you are going to
advise readers to modify their diet, do give them sufficient information
to make an unbiased choice.
K. G. Wormsley Worthing, West Sussex
Letters: Handle with care
Feline distemper in lions (This Week, 11 June) is not the first exotic
virus normally associated with domestic animals to suddenly emerge in Serengeti
wildlife. Between 1985 and 1987 antibodies to canine parvovirus were found
in serum samples from a pack of an endangered species, the African wild
dog (Lycaon pictus), whose home range covered the area in which the lions
are now dying.
Also in the same area from 1988 to 1990 antibodies to rabies were found
in serum samples taken from healthy non-vaccinated wild dogs which had probably
survived exposure to the virus. Rabies is virtually absent in protected
wildlife areas in Africa, but subsequently other wild dogs in the Serengeti
and nearby Masai Mara region died from rabies, including some from packs
that had been vaccinated against the disease.
Like the lions, the Serengeti wild dogs were not in direct contact with
domestic animals, a potential source of the viruses, but these wild dogs,
again like the lions, were frequently ‘handled’ for radio collaring and
blood sampling. Could this intervention have accidentally introduced exotic
parvovirus and feline distemper viruses into the study populations? Could
stress caused by handling have compromised any natural immunity to viral
diseases such as rabies?
It is interesting that there is some evidence of immunosuppression
in the Serengeti lions (This Week, 4 June). The occurrence of exotic diseases
in study populations needs to be urgently investigated but without using
highly invasive techniques.
Roger Burrows University of Exeter
Letters: Farm freedom
Gail Vines’s article about the Royal Society for the Prevention of
Cruelty to Animals’s Freedom Food labelling scheme (This Week, 9 July) gave
substantial coverage to criticism that the standards set for the scheme
were too low. However, it is a fact that the standards are not only the
result of much consultation with welfare scientists and others, but also
cover in a comprehensive way the whole of the animal’s life.
Further, the majority of producers who join will probably have to make
changes in their production systems. And that is the crux of the matter.
We need to promote change in a realistic and achievable way in those undertakings
that rear farm animals for the mass consumer market. We do not aim to create
another niche scheme but to generate a mechanism through which many millions
of animals will benefit.
Launched on 6 July, early signs are that Freedom Food will be a resounding
success. Any profit made will be ploughed back into farm animal welfare
research. Only with the aid of welfare scientists with practical, on-farm
experience can we find out how to stop ‘free range’ hens cannibalising one
another and how to engineer alternative systems to the sow farrowing crate
in large-scale commercial practice. The sooner that day comes the happier
everyone will be, including the farm animals.
Tony Suckling RSPCA Horsham, West Sussex
Letters: Quantum vibrations
My aim has not been to compose music for plants (This Week, 28 May).
It stems from a work in theoretical physics, which predicts the existence
of generalised quantum waves travelling through scale, thereby connecting
different quantised scales of a physical system; and allows as an example
the calculation of sets of frequencies associated with protein synthesis.
One of the predicted scale ranges, being close to Avogadro’s number,
provides a simple and ethical way to check the correctness of the corresponding
equation: namely, that the transposition of those frequencies from the predicted
range (thus to the audible range approximately), should be able, by scale
resonance, to stimulate – or inhibit, using phase opposition – the corresponding
protein synthesis.
Experiments on plants have been devised for this reason, with success,
and are currently being repeated by a Swiss industrialist who is not an
‘admirer’ but himself an independent researcher, and contributes for this
reason to the coast of the patents. Useful applications include health,
since as human beings do in addition possess ears, this provides a way to
heal by directly acting on a desired protein synthesis in a way then controllable
by the person, therefore respecting human rights.
Joel Sternheimer Paris
Letters: Feminist first
Susan Katz Miller states that Carl Djerassi’s proposal that young men
should make donations to sperm banks and then be sterilised was ‘inspired
by a chance meeting with Stanley Leibo’ (This Week, 9 July). This may be
the case, but I suspect she was duped.
‘Djerassi’s’ proposal was in fact first made by Germaine Greer and published
16 years ago (The Spectator, 14 January 1978) under the ironic title ‘A
Modest Proposal’. Given that Djerassi was, at around that time, a well-known
object of Greer’s scorn, I would guess that either he saw the article, or
was told of it. In his current commentary in Nature, Djerassi admits that
the sperm bank option has been previously considered – but refers only
to work of his own, published in 1981.
The proximity of this reference to 1978 may be mere coincidence. What
is certainly true is that it is the convention in science – and desirable
in science journalism – that prior published sources of ideas should be
acknowledged, even those from feminists. Of course, all parties might be
innocent here; but I take this chance to correct the oversight or ignorance
of at least one of them.
Jeremy Burgess Wymondham, Norfolk
Letters: Raining on Mars
As Stuart Henderson pointed out (Letters, 2 July) it would be impractical
to process the comets in the outer Oort cloud, to get water for terraforming
Mars.
However, the recently confirmed Kuiper belt of comet-like objects up
to 250 kilometres across, beyond Neptune, may have a total mass 100 to 1000
times as great as the asteroid belt.
If some of these objects could be sent towards an encounter with Neptune,
the gravity would slingshot them towards the Sun (like the Voyager probes
in reverse).
There are enough of them to provide Mars with oceans of water, or simply
crack the crust, kickstart the dormant plate tectonics, and let the volcanism
return some of the water lost to the interior by subduction (according
to a revised model of Mars by N. H. Sleep).
Birger Johansson Umea, Sweden
Letters: Paro-what?
Roy Herbert’s article on Science Matters by Robert Hazen and James Trefil
(Review, 2 July) commends it as being easy to read, with language which
‘verges on the colloquial’. Would that his review had followed the same
principles rather than referring to ‘this paronomastically titled book’,
which sent me to my dictionary. Why not ‘punningly’?
J. L. Turner Leeds
Letters: Cool title
My husband and I have been discussing Fred Pearce’s article on global
cooling (‘Not warming, but cooling’, 9 July). We are agreed that what is
needed is a catchy title for this effect, so that the media can enjoy making
as much of it as they have of the (now presumably discredited) idea of
global warming. We would, therefore, like to coin the phrase ‘the igloo
effect’.
Wendy Perkins Ashford, Kent
Letters: More on Murphy
I remember seeing the TV programme mentioned in the letter by Ian Fells
(16 July), in which people dropped buttered slices of bread to test the
validity of Murphy’s Law.
Surely the whole point of Murphy’s Law is that the environment tends
to behave perversely to the disadvantage and annoyance of the individual.
Since those taking part in the experiment had apparently no intention of
eating the buttered bread nor responsibility for cleaning the floor, they
would not care which way the slices fell and Murphy’s Law would not apply
in their case.
Kenneth Wood Redcar, Cleveland
* * *
Correction: In ‘Can we learn to love the wind?’ (16 July), a typographical
error resulted in British Standard number BS4142 being printed incorrectly
as BS4124.
Letters: Speed and height
John Wann makes a plea for spending on virtual reality systems (Letters,
16 July), because some depth cues were absent from our computer simulation
of pedestrian collision. That was intentional. We wanted to study the effects
of size and optic flow in isolation.
When the simulation supported our expectations, we proceeded to a better
method than virtual reality: reality itself. We predicted how accident statistics
would be influenced if drivers misjudged children as larger people further
away. For example, increasing the eye level of a driver should reduce the
illusion, thus lowering the proportion of pedestrian casualties who are
children.
That prediction was dramatically confirmed by analysis of all accidents
involving lorries, vans and cars for one year, which indicated that over
50 per cent of child pedestrian accidents are due to this driver error.
Alternative explanations were examined and discounted, and other tests provided
corroboration.
It would, of course, be gratifying if the Department of Transport provided
‘ 拢100 000 or so’ for virtual reality systems to examine the problem
and to develop solutions. But the DoT lacks enthusiasm for research which
is liable to reveal its mistakes, and we believe that there are features
specific to British roads which cause perceptual problems for child pedestrians
and give them one of the worst accident rates in Europe.
Peter Baker, in the same issue, claims that children are killed because
drivers drive too fast, not because of an optical illusion. But both are
correct. The root cause of the illusion is speed, because it forces drivers
to use an inefficient method of judging time-to-collision. Our paper, therefore,
recommends lower traffic speeds, and we agree that 30 mph is ‘a ludicrous
speed’ in many streets. If the standard urban speed limit was reduced to
20 mph, which would have little effect on journey times, most child pedestrian
accidents would be prevented. A research priority should be to find better
ways to enforce this than filling streets with humps.
Douglas Stewart University of Aberdeen
Letters: Alive and well
In your editorial ‘End the chaos at Chernobyl’ (Comment, 16 July), you
state that non-nuclear energy is ‘far more of a sunrise industry than the
dying nuclear firms’. However, as illustrated in the latest industry report,
The Global Uranium Market: Supply and Demand 1992-2010, published by the
Uranium Institute, this is clearly not the case.
Based on replies by utilities worldwide to a survey of their plans for
nuclear capacity, and predictions of future global energy demand by the
World Energy Council, the Uranium Institute forecasts that global nuclear
generating capacity is set to increase by almost 20 per cent by 2010.
Nuclear has had a share of over 16 per cent of the global electricity generating
market since 1987, and this share has not diminished, despite increasing
world electricity requirements – hardly indicative of a dying industry.
Many countries are firmly committed to nuclear energy and are expanding
their use of this resource. Japan, South Korea, Taiwan and France all have
long-term plans for future nuclear expansion. In the US, the world’s biggest
electricity consumer, nuclear accounts for 20 per cent of electricity generation.
In France, the nuclear share is 78 per cent. Worldwide, 430 nuclear power
reactors were operating in 1993, 92 of which have come on line since 1987,
providing an extra 86 770 megawatts of capacity in 17 countries. There are
currently 55 new nuclear reactors under construction around the world, and
eight new reactors are scheduled to start up in 1994. Many more are planned.
With increasing international importance being placed on the environment,
it should be noted that nuclear energy is the only form of baseload electricity
generation, apart from hydro, that does not produce significant atmospheric
emissions. It is hard to see how targets for limiting the emission of greenhouse
gases can be met without the continuing use of nuclear. In Germany alone,
2 billion tons of CO2 emissions have been saved since the introduction
of nuclear energy in 1961, including 150 million tons saved in 1993 alone.
Far from being a dying industry, nuclear energy is alive and well, and
set for growth.
Robin Bhar The Uranium Institute, London