Letters : Throw in the sinks
Stroud, Gloucestershire
The preparatory negotiations for this year’s Climate Change Convention in
Kyoto appear to consider only half the problem of rising levels of atmospheric
carbon dioxide (“Chill winds at the summit”, 1 March, p 12).
It is essential to include both sources and sinks of CO2 when
attempting to establish the basis for the kind of global trade in CO2
permits proposed by Michael Grubb and others. Thus, nations that have large
areas of sustainable forest or wetland would find themselves in possession of
real assets, in the form of CO2 credits, which could be offset against
debt (CO2 emissions) or traded like any other commodity on the global
market.
If such an economy is eventually to attain the magnitude necessary to
stabilise atmospheric CO2 levels, an accurate, ongoing, global audit of
the entire CO2 cycle will undoubtedly be required. Of course, this
might be difficult to achieve and there is ample scope for controversy over the
apportioning of the world’s oceans but, in the absence of a commonly accepted
baseline against which to measure progress, it is difficult to imagine anything
other than continuing disagreement.
Letters : Scans in the dock
Rockhampton, Queensland, Australia
You argue that brain imaging such as PET scans should be used for diagnosing
medical conditions, not in defending criminal actions (Editorial, 22 March, p
3). Would that were so in Britain in respect to children with Attention Deficit
Hyperactivity Disorder (ADHD), a disproportionate number of whom will end up in
prison.
Britain is years behind the US and other developed countries in the
management of this condition, with some psychiatrists pooh-poohing its
existence. Now PET scans can reveal the functional differences in such cases,
with some overactivity in the visual and auditory cortex (hence inattention),
and underperformance in the “executive” prefrontal lobes (and thus hyperactivity
and impulsiveness).
Yes, PET scans should play an important role in validating this condition,
and help ensure its accurate diagnosis and proper treatment, rather than
confirming after the event our failure to help sufferers who end up in the
dock.
Letters : . . .
by e-mail
You state that: “Neuroscientists have a hard enough time working out how the
brain creates the mental illusion of visual perception, let alone the illusion
of moral judgment and free will.” I don’t want to be unfair to neuroscientists,
who must on average have as much common sense as anyone else, but it is about
time that your magazine abandoned this kind of ultra-materialism.
Visual perception is not an illusion: it enables me to read your magazine,
and I am in fact so convinced of its reality that I am prepared to spend good
money on a pair of glasses to enhance it. Likewise, I will not accept that my
abilities to reason and make choices (including moral judgments) are an
illusion. To anyone who says they are, I reply: “Speak for yourself. I think,
therefore I am.”
Letters : Children crossing
Aberdeen
Three years ago you ran a story and an editorial on my work on the driver’s
optical illusion that causes children to be killed or injured in road accidents
(This Week, 18 June 1994, p 4 and Comment, p 3). This work had wide coverage.
What should have followed was research and development by the Department of
Transport, but they seemed unable to appreciate the significance of my findings,
despite the evidence of several different tests and the huge potential for a
reduction in child casualties.
In my work I made one prediction which could only be tested recently. I
suggested in technical papers that the danger to children from this perceptual
error “should be greatly reduced by lower traffic speeds” and that “it can
therefore be predicted that the reduction in pedestrian casualties will be
greater for children than for adults”, although at that time I had no way of
testing this.
A few months ago, however, the Transport Research Laboratory published a
study of the effects of reducing speed limits from 30 mph to 20 mph. It showed
that pedestrian casualties decreased by 70 per cent for children but only 45 per
cent for adults, despite the fact that more children are allowed on to streets
when traffic calming is applied.
These figures add further support for my conclusions and emphasise the need
to reduce urban traffic speeds.
Letters : Dope on dope
Corpus Christi, Texas
Kurt Kleiner quotes American bureaucrats who must have smoked too much of
what they think others shouldn’t touch (“Turn on, tune in, get well”, 15 March,
p 14).
Health secretary Donna Shalala’s statement that “our teenage drug problem is
for the most part a marijuana problem” is an outright distortion. Some figures
are illustrative. The Monitoring the Future study, done annually by the
University of Michigan, is the government’s “bible” for drug use among
adolescents.
The study for 1996 shows that 4.9 per cent of 12th graders have smoked
marijuana within the last 30 days, 22.2 per cent of 12th graders smoke
cigarettes daily, and 30.2 per cent have engaged in binge drinking of alcohol,
at least once, within the past 14 days. Binge drinking is defined as five or
more drinks or beers in succession, at one sitting. Shalala is well aware of the
facts on alcohol and nicotine, yet continues to insist that marijuana is the
problem.
The National Institute on Drug Abuse, NIDA, is no less dishonest. The claims
of memory impairment, brain damage, lung cancer and immune system damage have
all been debunked by research within the past year in the US and Australia.
NIDA’s policy of providing marijuana only to studies aimed at finding negative
effects of marijuana has not been successful.
Letters : . . .
San Mateo, California
The conclusions of the panel of experts convened at the request of the
National Institutes of Health were amazingly frank and accurate, given the
political dynamite with which they were dealing.
The opinion that whatever evaluation of safety and efficacy marijuana is
subjected to, it will have the added burden of proving it is the best agent
available would be regarded as facetious if made about any other class of
therapeutic agents. In the case of marijuana, for a scientist to allow that such
an outcome is even possible is regarded as dangerous heresy and its utterance a
mark of defiance.
This is the sad state of affairs American drug policy has brought us to. The
most realistic hope at this point is that if enough rational people are
motivated to think about these problems, they may gain enough insight into the
ridiculous and destructive nature of the paradigm of doctrinaire global drug
prohibition to want to change it.
Letters : Misplaced
by e-mail
I was fascinated by the account of Vilayanur Ramachandran and William
Hirstein’s work on people with Capgras syndrome (New 杏吧原创,
Science, 22 March, p 19). My mother, in the last two years of her life, suffered
from something almost identical except that the linkage she lost was to places,
not family.
She suffered from a major stroke (left side) ten years before her death, then
recovered quite well until about seven years later she started to have a series
of small ischaemic strokes. The effects were bizarre. She was staying with my
brother at the time, and would become convinced that we had removed her and her
belongings to some other place.
She was totally familiar with his house and his garden, and was surrounded by
her own furniture. She would tell me that she had been moved, but that we had
been so clever to take all her things with her.
She would recognise the place, saying: “Isn’t the garden nice? It’s just like
John’s.” I would have to explain that it was John’s, but she wouldn’t have that.
Although she knew everything in her surroundings, it was somewhere
unfamiliar.
The effect lasted for several months and it would distress her, at least in
part, because she felt that we were lying to her when we said that she hadn’t
moved. At the same time she never had any problems identifying members of the
family, either in person or in photographs. I don’t know if the effect
disappeared or if she accommodated to it; after six months or so she ceased to
complain about being in unfamiliar places.
I deduced (not being a neuroscientist) that there was some specific region of
her brain that dealt with familiarity of objects, but not of people. It was
quite independent of the linkage to remembered features and objects. I now
understand that it must have been the linkage to emotion that was affected, but
only in that narrow field.
Letters : Feed them flowers
Sheffield
All sorts of flower bulbs were part of the regular diet of the ancient Romans
(Letters, 15 March, p 51, and Feedback, same issue). They seem to have been
particularly partial to gladiolus and asphodel, which they baked in the ashes of
a fire, as we would cook onions at a barbecue. We owe this information to the
elder Pliny, who was also probably the nearest thing to a scientist the Romans
produced.
The second century cookery book attributed to Apicius offers several recipes
for bulbs boiled or fried and dressed in various ways, or used in casseroles or
stuffings. According to Varro, they were highly regarded as an aphrodisiac and
featured regularly at wedding banquets.
Letters : Managing mahogany
London and Washington DC
It has come to our attention that some sources are misconstruing Bob Holmes’s
article on mahogany to imply that we advocate logging mahogany to save the
forest (This Week, 22 February, p 10).
This is not the case. Our report focused on what is done with forests after
mahogany has been logged. We caution here against strategies for the
regeneration of a single species, such as mahogany, at the expense of much of
the other fauna and flora. In this context, we warn against sacrificing the
forest to save mahogany.
We do not advocate wholesale logging of mahogany. On the contrary, we urge
governments, industry and the environmental community to work toward conserving
representative wild populations of mahogany, such as through the current
proposal to have international trade in mahogany regulated under CITES Appendix
II. By this means, National Parks and reserves may be protected from the
unmanaged, often illegal, logging that is currently taking place.
Letters : Feel the steel
Pittsburgh, Pennsylvania
Michael Judge discusses the creation of a stronger, stiffer, lighter alloy
made from metals reinforced with microscopic wires of another metal (“It takes
two”, 8 March, p 36).
The process for creating the new alloy may be a breakthrough, but a similar
alloy has been around for hundreds of years. The material is called Damascus steel.
It has been used for generations by knife and sword makers in Japan.
Damascus steel is created by taking two steels, often one softer than the
other, and putting them together like plywood. They are then hammered flat, and
the flattened piece folded over and over and hammered flat again, sometimes
hundreds of times.
Much like the strength of a piece of plywood, Damascus steel is extremely
strong. There were even reports of Japanese swords cutting clear through
Russian soldiers’ gun-barrels during the Russo-Japanese War.
The process that Judge refers to is different from making Damascus steel in
that it disperses metal A throughout metal B, not in alternative layers, but
more like an evenly-distributed foam which is then drawn out, leaving filaments
of one metal inside the other. The molecular structure of the two dissimilar
metals creates a situation where if there was a crack in metal A, the crack
wouldn’t travel through the entire forged piece because it would be stopped by
the dissimilar angle of the molecular structure of metal B, thereby preventing
failure of the entire piece of metal. Much the same is true of Damascus
steel.
This process is intriguing, though, because it brings the fantastic strengths
of Damascus steel without the cost and labour intensity involved in manufacture.
It would be interesting to see whether the new alloy can withstand the corrosive
effects of the electrochemical reaction that occurs between metals when in the
presence of an electrolyte.
Letters : Smith's Bath
Rennes, France
Born and bred in Bath, and a geologist to boot, I was shocked to hear Sue
Bowler refer to the building stone as “Bath’s golden sandstone” (Review, 22
March, p 47).
William Smith (father of English geology and erstwhile resident of Bath) must
be revolving in his calcareous bedrock.