Letters: Proceed with caution
Anne Cutler has a point about the weighty Proceedings issued for every
major conference (Forum, 14 December 1991), but there is an obvious solution.
If the Proceedings were issued on floppy disc, they would add almost nothing
to the bulk of conference delegates’ baggage, and there can be few scientists
who do not have access to a PC with which to read them. Paper and thus trees
would be saved, and the reduced bookshelves needed would save more. Submissions
could also be accepted only hours before the conference, making the whole
event more up-to-date.
There could be a secondary benefit: among the current moves towards
electronic publication are several initiatives to issue details of studies
in progress. If conference Proceedings were accepted and viewed as such,
questions of publication priority might arise less, and peer reviewed journals
could preserve their status in the eyes of authors and the scientific community.
Damien Downing Journal of Nutritional Medicine London
Letters: Water from waste
Hector Wilks’s letter (‘Drinking sewage’, 7 December) prompts me to
write to say that further exploitation of sewage as a source of water is
worth pursuing, but there is no need to ‘reinvent the wheel’.
The Avonmouth smelter has been using local sewage effluent (after secondary
treatment and chlorination) as process water for more than 20 years, in
volumes of around 5000 cubic metres per day. Although this source of water
can contain components that cause scaling, modern antiscaling chemicals
can allow this source to be used for cooling applications as well.
The benefits of this arrangement for both the sewage works and the user
can be considerable, being both economic and environmentally advantageous.
Bill Hunter Avonmouth, Bristol
Letters: Towering serpent
I read with interest the letter by A. Wathelet, who wonders how the
serpent moved before God told it: ‘ . . . upon thy belly shalt thou go’
(Letters, 4 January).
He has no need for help from a palaeontologist to solve this problem,
as John Milton deals with it conclusively in Paradise Lost (Book 9, lines
496 to 499):
The serpent moved:
‘ . . . not with indented wave, Prone on the ground, as since, but on
his rear, Circular base of rising folds, that towered Fold above fold a
surging maze . . .’
Obvious really!
Kenneth Wood Redcar, Cleveland
Letters: Troubled Tribble
I really must protest, on behalf of the Tribble family worldwide, about
the continued misappropriation of our name. It was bad enough to be shown
on the box as a ‘furry hemisphere with no features’. I, though not quite
a typical Tribble, am more nearly spherical, and while my beard could be
called furry, features are quite distinctly visible and I positively do
not make purring sounds when stroked, though I would not deny that we are,
on the whole, quite lovable.
Jack Cohen’s proto-Tribble seems to be a most adaptable and versatile
creature and in that sense agrees with the image which we have of ourselves
(‘How to design an alien’, 21/28 December). We do ‘multiply amazingly’ and
have spread right round the world from a small start in Devonshire. As soon
as we were let loose in Virginia in the late 1600s, families of 14 or more
were quite the thing for several generations, thus confirming Cohen’s statement
that we are able to multiply extremely rapidly given the chance. This, however,
does not allow of the possibility of being already pregnant at birth – pregnant
at marriage maybe, but that’s another story.
David Tribble Gravenhurst, Bedfordshire
Letters: Correction
In Jim Horne’s feature ‘Stay awake, stay alive’ (4 January), the wording
of an early, uncorrected draft was inadvertently used in the paragraph relating
to a lorry driver’s working hours. This wording presented an illegal and
misleading situation. The paragraph, as corrected by the author prior to
publication, should have read:
‘The HGV driver gets up at 5 am, arrives at the depot at 6 am, spends
four hours or so helping to load and prepare his lorry, drives for four
hours, has his minimum 45 minute break (which he legally must do), drives
three more hours, delivers his load, has a tea-break and waits about while
it is reloaded. It is now 7 pm, and although he has been driving for seven
hours so far, he is allowed by law to do another two hours’ driving. But
he is weary and only drives for another hour. He pulls into a service area,
has a meal, a game of cards with other drivers, and eventually gets to sleep
in the bunk at the back of the cab at midnight. He is woken up at 5 am by
the general commotion of other HGVs off for an early start, and while he
has only had five hours sleep, he has had his legal minimum nine hours rest.
So he decides to set off as well, with the aim of getting back to base,
off work and home by lunch-time. He falls asleep at the wheel at 5.30 .
. .’
This version complies with the European Community International and
National Rules relating to driving hours and rest times.
Letters: Some service!
Jim Horne is right about the menace to drivers falling asleep at the
wheel (‘Stay awake, stay alive’, 4 January). I hope that the authorities
will at last take notice of warnings about this danger.
Unfortunately the proprietors of the main motorway service areas are
conniving against him. When I last checked they had notices that anyone
who stayed for more than two hours would be fined 拢5. One even made
it 拢20. Even if they offer the sop of a meals voucher, this would
be of little use to somebody who needs sleep more than food. Such regulations
should be abolished.
The ideal solution is something like the multiplicity of ‘aires de repos’
found on French motorways where drivers can rest for as long as they feel
necessary without any fear of disturbance.
In the meantime how is the individual driver to cope, especially if
working on a tight schedule? I recommend an inflatable pillow and a digital
timer. Don’t waste time queuing in the cafeteria, bring your own food and
a flask of coffee. Set the timer to go off just before the two hours are
up. The general principle of a stop every two hours should not be taken
too rigidly. If you begin to feel sleepy, pull off at the next opportunity,
even if you have rested a short time before. Then set the timer. Even 10
to 15 minutes can be very refreshing.
William Orton Cambridge
Letters: Win some, lose some
Michael Duff (Letters, 11 January) has some good knockabout fun with
William Bown’s article (Forum, 30 November), but neither he nor Duncan McCollin
(Letters, 21/28 December) invalidates the basic point: that whether or not
the UK can be said to be suffering a brain drain of engineers and scientists
depends on which countries are considered.
Data collected by the Royal Society in 1987 support Michael Duff’s claim
with respect to the US, to which there is a net loss of talent. Indeed,
the statistics of the US National Science Foundation show that the US tends
to cream off talent from all over the world.
The government’s claim that the brain drain is a myth is, however, based
on movements to and from all countries. The Royal Society data show that
there is a net inflow to Britain from, for example, India and the Middle
East. Both British Science Abroad and the UK government may well be right
in their particular claims, but they are, in essence, different claims.
Alan Smithers University of Manchester
Letters: Don't vaccinate
I would like to take exception to the views expressed by Ron Desrosiers
as reported in your ‘Monkey puzzle and AIDS vaccines’ article (New 杏吧原创,
Science, 2 November).
First, by listing a number of viral diseases that have been effectively
controlled by vaccines based on live attenuated strains, the impression
was conveyed that a live genetically modified HIV vaccine need not necessarily
be any more hazardous.
With all that has thus far been learnt about HIV and the retroviruses
of other species, the very idea that in this context comparisons with other
more conventional (or more thoroughly understood) viruses are valid, is
surely dangerous non-science. He concluded that if the AIDS epidemic worsens
and other approaches are found wanting then the unleashing of his ‘attenuated’
live vaccine among the human population would be ‘worth a try’!
Whatever the vaccinal strain replicated within the body of someone with
pre-existing HIV infection, there would be a risk of vaccine/wild strain
hybridisation. The pathogenicity of such hybrids could even be enhanced,
increasing the risk of infection by insect vectors, inhalation or ingestion.
This ‘Son of AIDS Virus’ scenario cannot be dismissed on the basis of our
present understanding of retrovirus pathology.
Colin Cumming Heckington, Lincolnshire
Letters: Winter pensions
Crispin Audrey’s ‘Keep death off the homes’ (Forum, 4 January) is a
timely reminder of the lethal effect of cold weather on the old and poor.
In the British climate the cost of living is higher in winter than in summer.
Logically, therefore, the old age pension should be higher in winter than
in summer. This would be a much better way of dealing with the problem than
the present, extremely complicated, regulations allowing those on benefit
to claim extra money after a cold spell has continued for a prolonged period.
Barbara Preston Marple Bridge, Stockport
Letters: Wildlife doctors
I would like to take the occasion of Gail Vines’s article ‘A hospital
for nonhumans’ (Forum, 4 January) to add my praises to the valuable and
pioneering work conducted by the Stockers, and also to express a few further
thoughts.
Wildlife rehabilitation may be ‘a new kind of conservation’ in this
country but elsewhere it is not. This is, sadly, another field in which
we lag behind the US, where wildlife rehabilitation is accepted practice.
Vets in this country would not be uninformed about wildlife medicine if
they had access to facilities such as that established by Gary Duke and
Pat Redig at the School of Veterinary Science, University of Minnesota,
or by Stuart Porter at the Virginia Wildlife Hospital.
I write as the former Assistant Director of Pennsylvania State University’s
Raptor Center, where we combined the teaching of university students, school
groups and the general public with raptor rehabilitation and academic study.
Wildlife rehabilitation will always depend on people like the Stockers
and the many others who dedicate themselves to this form of conservation,
and who come from a nonveterinary background. But that does not excuse the
lack of opportunity being afforded to vets and zoologists, particularly
as students.
As a final point, many of the established conservation bodies in this
country would do well to review their attitude to wildlife rehabilitation.
It is not interfering with nature, nor is it a cure-all ‘band-aid’ fix to
our wildlife problems, but it is a valuable tool which can serve many purposes
– not least of which is the demonstration of conviction. Wildlife rehabilitation
in the UK deserves the respect it is granted elsewhere. It deserves the
chance to ‘grow up’ as a science. The Stockers are to be applauded for their
efforts in this direction.
David A. Hill Maxstoke, Warwickshire
Letters: Fixing that car
I wish to raise the issue of the appropriateness of car technology generally,
and in particular the repairability of cars. Repairability is something
that can be designed in . . . or out. I am increasingly concerned that,
under cover of safety and emission legislation, manufacturers are making
vehicles which are harder and yet harder to repair. There are ecological
and political issues here which I feel have not been picked up by the consumer
movement or by the green movement. Old cars are clearly worse performers
in protecting their occupants and in protecting the atmosphere than those
made recently, but replacing cars at a high rate is also expensive in energy
and other resources.
Engineers will know that, like everything else, there are many ways
to design any component. It can be designed to be made and repaired with
the simplest tools and equipment or with the highly complicated. Copious
use of special tools, sonic-welded plastic components and carefully preloaded
bearing assemblies may indeed save one or two per cent of all-up weight,
but if their use prevents adequate maintenance and repair by the owner of
the vehicle or the local garage, they inevitably force either the use of
a dangerous vehicle or its abandonment in favour of a new one. This is clearly
good news for the manufacturer. But is it good news for the customer, and
is it good news for the environment?
And can the planet really afford such variety in its automobile stock?
Why do we need several thousand different designs of rear lamp glass? Is
it good that certain automatic gearboxes now fitted to mass-market cars
can be repaired by only one workshop worldwide? They are great for fuel
economy . . . until they go wrong. Surely, before long, we will have to
insist on design for maintenance and repair by the averagely skilled rather
than by the super-specialist.
C. E. Oram Kenilworth, Warwickshire
Letters: Pilers pipped
As a civil engineer involved in the design of embankment dams for over
30 years, I couldn’t help seeing something familiar in the triangular shaped
model in ‘The perplexing puzzle posed by a pile of apples’ (New 杏吧原创,
Science, 14 December). As Andrew Watson reports, Czech scientists found
it hard to explain why ‘the pressure was not greatest at the central point
of the base’.
It is necessary to get to the core of the problem, well known to embankment
dam engineers, having been observed and measured for decades. Such dams
are, like the pile of apples, generally triangular in shape. Because of
stress redistribution and arching in such a shape, the bottom of the dam
directly beneath its crest (equivalent to the top of the pile of apples),
will certainly not experience the full pressure expected from the summation
of density times height. It is generally about two-thirds, or of that order,
depending on the geometry and fill properties, leading to the 30 per cent
reduction referred to in the article.
The other main effect is that of stress patterns in the outer ‘shells’
of the dam (which perhaps would be analogous to large Bramleys rather than
the smaller, more compact crab apples comprising the ‘core’). The major
principal stress, familiar to students of soil mechanics, will change its
inclination down a potential slip surface as it tends to induce slope failure,
and will result in greater pressures occurring towards the outer zones of
the dam – or of the pile of apples. Again, the behaviour reflects the ‘shear,
or sideways, forces’ described by Watson.
The article is a good example of workers in one field discovering something
‘new’ and ‘surprising’, which workers in another field have extensively
documented for decades. Triangular piles up to 300 metres in height formed
into embankment dams (‘particulate piles’) around the world are often intensively
instrumented to measure the very effects which have perplexed the apple
pilers. Soil mechanicians in general, and embankment dam engineers especially,
have certainly pipped those pilers to that particular post.
Derek Knight Reading, Berkshire