Rooks and ravens
I enjoyed your Inside Science feature “The Species Enigma”,
13 June. However,
the author is mistaken if he thinks that Corvus frugilegus is the
raven. It is in fact the rook, the raven being Corvus corax.
No right to clone
Mark Eibert argues that cloning is a “reproductive freedom” under the US Constitution
(Letters, 13 June, p 51). It should be pointed out that this
interpretation is far from universally accepted.
It is not accepted, for instance, by the Governor of Michigan, John Engler,
who on 3 June signed into law the first permanent state ban on cloning, saying:
“While cloning people has made for interesting science fiction novels and
movies, in reality the concept is unthinkable.” Nor is Eibert’s interpretation
accepted by the 24 other states considering bans.
To support his conclusion Eibert must interpret the right to bear or beget
children as extending to any technology for producing babies including, in
principle, the Brave New World scenario in which embryos with
predetermined characteristics are grown in bottles.
No court is going to accept this. Common sense suggests that a line must be
drawn somewhere between the freedom to have children on the one hand and
industrial-scale manufacture of babies on the other. The fact that courts have
placed IVF on the acceptable side of this line in no way prevents cloning being
placed on the other.
Since cloning could not allow anyone to have “their own child”, but only
their identical twin (or the twin of a third party), the argument that it is a
“right” is tenuous at best.
My own view is that science does not have the power to discover fundamental
rights we never knew we had, in the US Constitution or elsewhere. One might as
well argue for a basic human right to breathe water as to reproduce
asexually.
Cloning is a new issue and must be judged on its merits. The moral argument
against cloning is that it gives an unacceptable degree of control over the
characteristics of the child who is produced, allowing his or her genes to be
determined with 100 per cent accuracy (though limited specificity). This is a
power that natural parents do not have.
Testing for BSE
The article on BSE in Switzerland quoted one of us as saying that “1800
subclinical cases may have ended up on the table” last year
(This Week, 13 June, p 4).
The full quote was: “If you assume the same incidence in the general
population, 1800 subclinical cases may have ended up on the table. But the
actual number of subclinical BSE cases present in the current population really
has to be determined.” The general incidence of subclinical BSE in Switzerland
may be less than in the culled herds tested so far.
The results presented in the article were also not represented entirely
correctly. Out of 1761 animals examined, four animals tested positive by both
immunohistochemistry and the Prionics immunoblotting test. Three of these
animals tested positive for spongiform change. In addition, two further animals
tested positive by immunohistochemistry alone and another two by the Prionics
test alone. The differences between the test results may lie in the techniques
used or may simply represent the fact that the two methods cannot be performed
on the same tissue sample.
In conclusion, three animals each tested positive by three different methods
and one by two methods, while four animals were positive by only one method.
Counting to kill
It is not simply that this year scientists “began calculating population
levels” of North Pacific Bryde’s whales
(This Week, 30 May, p 14) but that,
urged by scientists mainly working on behalf of Japan, the International Whaling
Commission’s scientific committee wanted to conduct computerised “simulation
implementation trials”. These would lead directly to the calculation of catch
limits, especially for a type of whaling which has been prohibited by the IWC
since 1979鈥攏amely, the use of factory ships to harvest Bryde’s and other
large species.
Norway has for several years used the results of corresponding trials
concerning minke whales in the North Atlantic to calculate its self-awarded
catch quotas for that species. It deflects criticism by claiming it is only
doing what the scientific committee prepared. Most sharp observers of this scene
are sure Japan intends to do the same as soon as the Bryde’s trials are
completed in a year or so.
Lacrimose rats
Was the vet able to tell Sally Parsons why her rat was having an apparent nosebleed
(Letters, 30 May, p 58)?
And did he or she spot that the animal’s tears were also red?
Parsons’s pet was almost certainly infected with SDA (sialodacryoadenitis)
virus, one effect of which is secretion of porphyrins in mucus and tears. Unlike
blood, free porphyrins show a very pretty fluorescence under ultraviolet
light.
I can personally vouch that her pet can look forward to a long and healthy
life. Some years ago, I and colleagues at the Flour Milling and Baking Research
Association, as it was then called, set out to conduct the definitive life-span
trial of dietary fibre using some 1200 rats. In view of the time and expense, it
required the cleanest, healthiest rats on the planet, short of germ-free status.
A laboratory animal supplier allowed us to submit its animals for independent
scrutiny, and back came the report that while free of “specified pathogens” they
were infected with SDA virus. There are no prizes for guessing our initial
reaction to this news. Later, when blood pressures had subsided, we found, on
thorough searching of the available literature, that SDA virus might almost be
described as an obligatory passenger on rats, but that it only rarely produced
health problems.
We decided to go ahead with the trial. To our huge relief, most animals lived
a long, content, if somewhat unexciting life, and we were able to demonstrate a
protective effect of cereal dietary fibre against colonic diverticulosis.
Parsons may well be able to “see in” the millennium with her treasured
companion, which should bring pink tears to its eyes.
What's on TV?
Bryan Jones and Collette Clark’s suggestion that chicks find televisual
images “interesting”
(This Week, 4 April, p 25) is open to a number of
criticisms which need to be addressed before their findings are incorporated
into legislation.
First, it is difficult to see how the results from a short trial can be
applied to commercial situations where hens spend months in the same cage. Over
this period, the stimuli would probably lose effectiveness as animals became
habituated to them.
Stimuli were presented for a tiny fraction of the day, which ensured that
they remained attractive even after familiarisation had occurred. Another way of
investigating the chicks’ response would have been to present the screen-saver
for a significant proportion of the day and to record behaviour at times
throughout this period.
An active versus static screen-saver treatment would have controlled for
problems such as brightness, colour bias and screen flicker. Lacking this, it is
impossible to tell which features of the stimulus chicks were paying attention
to.
Finally, the case for providing visual stimulation is strong, but exclusively
visual enrichment may have little intrinsic interest for an animal if it cannot
explore the stimulus. A simple choice test between a visual and traditional
enrichment tool would be a good way of assessing the importance of each from the
animal’s point of view.
Flurry of Flyers
Feedback refers to “the first ever full-scale replica of the Wright Flyer”
(Feedback, 30 May).
I am afraid you have been misinformed. The Wright brothers
themselves sold several working replicas before the First World War.
Somewhat later, the original Flyer finished up in the Science Museum at South
Kensington in London, because no American museum would take it at the time. I
gazed upon it many times there during the 1930s, and read the plaque mounted in
front of it. Some time in the late 1930s it was returned to the US after some
hard feelings were expressed, and replaced by a full-scale replica, which I have
also gazed upon many times, and read the new plaque explaining what had
happened. If you visit the museum, you can also gaze upon it.
As Oscar observed
Having read the correspondence on religion and science
(Letters, 6 June, p 65),
I was reminded of a line by Oscar Wilde: “Religions die when they are
proved to be true. Science is the record of dead religions.”
Decimal divide
The Euro bug
(Feedback, 6 June) is no more than a minor irritation compared
with the decimal bug.
It seems to have escaped the attention of the powers that be that France and
Germany (among others) use the comma rather than the point as a decimal
separator.
Spreadsheets such as Excel don’t recognise numbers that aren’t in the format
defined in the operating system. Automatic editing/translating is nearly
impossible. Wordprocessing software is not immune to the bug either,
particularly when the decimal tab function is used.
The problem is that no one in authority has defined a decimal character or,
incidentally, one for separating thousands.
Naturally deadly
Your item on the Honourable Member for Ribble Valley Nigel Evans who warned
the House of Commons that cannabis contains “400 chemical compounds”
(Feedback, 6 June),
reminded me that I found a jar of presumably health-giving foodstuff in
the local supermarket with a label proclaiming: “This product is 100 per cent
chemical-free.”
Like Feedback, I wondered what in the Universe it could be made of.
Seriously, is there any way we can persuade people, and particularly marketers,
that the word “chemical” does not mean “synthetically manufactured chemical
compound”?
On a different, but related tack, I have tried for quite a long time to
convince my students that the word “natural” is not necessarily positive in
connotation. “Natural”, I protest, “like tetanus? Like the bite of a trapdoor
spider?” To no avail, I fear.
Letter
The Swiss reference laboratory for animal transmissible spongiform
encephalopathy at the Institute of Animal Neurology, University of Bern, has
been contracted by the Swiss government to conduct studies on the presence of
preclinical BSE in the Swiss cattle population.
The Prionics test detected six positive cases among the 1761 animals culled
in the slaughter programme. Four of these cases were identical to the ones found
by the reference laboratory. Two cases that were detected by the reference lab
were negative in the Prionics assay. Thus a total of eight positive reactors
were found, four of which overlapped.
All eight have been examined by Hans Kretschmar of the University of
G枚ttingen in Germany using a new assay which confirmed the diagnosis of one
of the two questionable cases identified by the reference laboratory. In total,
we now consider five cows to be preclinically infected.
For any disease with a long incubation period, one has to expect a larger
proportion of the infected population to be in the incubation period than
showing clinical signs. Until recently, no studies have reported the prevalence
of preclinical BSE. Estimates of preclinically infected animals that entered the
food chain undetected are based on modelling approaches. We estimate that the
maximum number of preclinically infected animals in Switzerland was reached in
1990, with potentially 1200 affected animals. Our estimate is that fewer than
100 were still present in 1997.
We consider the culled population of BSE herdmates to be a high-risk group.
The prevalence of preclinical disease observed within the cohort of culled
animals should therefore be considerably higher than the prevalence in the
general cattle population.
Letter
Parsons mentions that the authors of books on rats don’t appear to be aware
of this phenomenon. The same is true of gerbils, who frequently look as though
they have been bleeding if they suffer from a common allergy to the aromatic
oils in wood shavings.
What I find most disturbing is that so many small animal vets are also
unaware that a bloody-looking discharge from the eyes and nose doesn’t mean that
the gerbil has suffered some form of trauma. A couple of times a month I get a
call from a desperate gerbil owner whose vet has given up trying to treat an
injury to the nose.
Stumped by Varney
Regarding your piece on Kevin Bacon and six degrees of separation
(This Week, 6 June, p 7),
Keith Maggione, film buff extraordinaire, played this game ad
nauseam until presented with Reg Varney (star of the great On the Buses
films of the Sixties).
Maggione has not been able to connect Varney to Bacon. Bacon would probably
be delighted if he knew.
Letter
Your mistake was quite a felicitous one as many people believe Tchaikovsky
was inspired by Beethoven’s piece entitled Wellington’s Victory, which
celebrated the victory at the Battle of Vittoria with an orchestral piece which
included the sounds of musketry volleys and cannon fire.
On deaf ears
I followed Netropolitan’s advice and visited the MidiFarm site in search of
Beethoven’s little-known “1812 overture”
(This Week, 13 June, p 19).
So imagine my disappointment when I found they seem to have replaced it with
the rather better-known one of the same name by Tchaikovsky.
Letter
Nice that you published Bellas’s letter on 13 June鈥攁nd that you did not
opt to change the publication date, just in case.
Letter
A few suggestions: “This page contains all valid proofs of methods to trisect
an angle or square a circle using ruler and compass” or “This page lists all
known even prime numbers greater than two” or “This empty page contains two
lies”.
Incidentally, I would seriously consider avoiding any airline whose technical
staff had so much trouble with the number 13.
Letter
About five years ago we employed a particularly pedantic engineer on a
software product, and at his insistence we replaced the words “This page
intentionally left blank” with “This is the only information this page contains”
in the product’s manual.
Letter
Always in very small print, any such page should read: “If you notice this
notice, you’ll notice this notice isn’t worth noticing”.
Letter
Bellas has produced a nice example of an oxymoron or inherently
self-contradictory statement.
To avoid this one can, of course, print an explanation on a facing page or at
the beginning of the manual.
Empty question
In response to the question raised by Tom Bellas
(Letters, 13 June, p 53),
the best words to put on an intentionally blank page are something like: “This
page left for your notes.”
If Bellas read the job adverts, he would notice that New 杏吧原创
seems to have started doing this where it can’t find an advertisement to fit the
space鈥攆or example, 13 June, p 83: “New 杏吧原创 Notes” (UK edition).