Who coined
My letter of 28 May (website letters) has stirred up some discussion with John McCarthy of Stanford University, who has proof of having used the phrase “artificial intelligence” in 1955, the year before I thought I had invented it.
Oddly enough, he has a vague memory of feeling that it was not of his own invention even then. This leads us to speculate that the phrase had been used by some now forgotten party before August 1955, and surfaced independently from our subconscious minds when we needed it.
Was UK prepared for foot and mouth?
Your editorial on bird flu states that: “When foot and mouth disease appeared in the UK in 2001, tactics were initially made up ad hoc” (6 August, p 3).
This they were not. They comprised well-established traditional policies, based on the rapid detection and slaughter of animals on infected farms and identification and slaughter or restriction on farms judged to have had contact with these farms, depending on the strength of that contact. These have been the basis of successful epidemic disease control in animals for many decades. However, in 2001 there had been wide dissemination of the disease throughout Great Britain before it was first reported, and it was this delay that was crucial in leading to the scale of the epidemic and the difficulty of bringing it under control.
The editorial continues: “But lack of foresight left the government with only one option, the dreadful slaughter of 6 million animals”. The “one option” to which you refer was the product of mathematical modelling during the epidemic, and this was indeed an untested and “ad hoc” approach. It is ironic that it was this very process that resulted in much of the extensive slaughter by instigating the automatic pre-emptive culling of all susceptible livestock on contiguous premises (farms neighbouring infected farms).
Subsequent published analyses of data from the epidemic have shown that this policy was not, as stated at the time, “the only option for controlling the current British epidemic”. Indeed, these analyses have vindicated the traditional policies and also demonstrated that the peak of the epidemic had passed before the extensive contiguous culling policies could have taken effect.
You also imply that modelling before an epidemic would lead to planning of a successful ring vaccination strategy. In fact, in the 2001 foot-and-mouth disease epidemic, the same early substantial dissemination rendered effective targeted vaccination hard to implement.
For the record
鈥� Our article on the melting of Siberian permafrost talked of “hollows and hummocks known as salsas” (13 August, p 12). The correct term is “palsas”, though we understand that they are also called “pingos”.
Picture perfect
I was a little puzzled by the piece about the “shy” ivory-billed woodpecker rediscovered in Arkansas (13 August, p 19).
The piece says “careful examination of blurry videotapes and photos failed to convince Richard Prum” of the woodpecker’s rediscovery. Yet below the article you show a nice clear photo of the bird. Since high-quality colour photos were not possible 60 years ago when the woodpecker was last seen, I assume the image is recent and part of the collection Prum examined. So why was it so difficult to identify the bird visually?
The editor writes:
鈥� The answer, as we should have pointed out in the article, is that the photo is of a very convincing stuffed specimen. It is not one of the recent poor-quality shots that heralded the bird’s rediscovery.
Travel sickness
Reading about Japanese attempts to bring down summer temperatures by pumping water out of Tokyo’s metro system and spraying it over the city’s roads, I started to wonder if the engineers behind the project have considered the risks of such a practice (13 August, p 30). The method would seem to be vulnerable to both accidental growth of pathogenic bacteria such as legionella and deliberate contamination performed by terrorists.
Life in Wisconsin wells
Underground life in the mid-western US is in some ways as unexpected as that reported from Western Australia (6 August, p 28).
While other US regions are known for their areas of karst and accompanying stygofauna, Wisconsin is not. It is covered largely by deposits left by the retreat of ice-age glaciers. However, in 1909 a species of stygobite amphipod was discovered in wells in three counties in the state. This Wisconsin Well amphipod may be unique among the state’s animals in having survived Pleistocene glaciation. Its taxonomically closest relative lives in the American west, across the Great Plains.
Progressive drying of the Great Plains at the end of the Tertiary may have split what was a continuous distribution of this amphipod and its relatives across the intervening regions in middle Tertiary times. Though this scenario means it must have lived in Wisconsin for over 10 million years, it is now at high risk of extinction, with a global conservation status rank of “imperilled”. A single surviving population of this species was rediscovered in 1986 by a museum expedition that had been alerted to its presence in a well that was about to be abandoned to allow a highway to be built.
We can only envy Australian zoologists who are able to go fishing down abandoned boreholes to retrieve specimens from subterranean mini-caverns. Laws mandate that new wells in Wisconsin are constructed in a way that prevents such access, and that abandoned wells must be filled. This makes sampling extremely difficult, and we at the museum feel lucky to have had the rare opportunity for what may have been a last glimpse of living individuals of this groundwater crustacean.
No contest
In his article on the “fight” for the naked quark, Dana Mackenzie creates the impression that theorists and experimentalists can compete with one another in pursuit of a scientific discovery (13 August, p 32).
There is something fundamentally wrong with this notion. Physics is at base an experimental science. Theorists can help us interpret experimental results, but theorists don’t measure, they calculate. Hence the assertion that the lattice QCD group was asked if they were interested in “measuring” the lifetime of the D-meson is absurd.
Sometimes new experimental results challenge theorists to revise or abandon their models. At other times the predictions of theories demand urgent confirmation by experiment. The interrelationship between theory and experiment is a complex dance in which at times one partner leads, and then the other. But it is never a competition.
The article is fascinating, nevertheless. It shows that a real breakthrough has been made in addressing a highly complex field with a fundamental theory. Perhaps, as a result, we will discover why the more phenomenological approaches to baryon spectroscopy, such as quark potential models, fit the measurements so well when we know that at a deeper level they cannot be right.
Babies get their way
Your article on babies’ cells “colonising” mothers’ brains suggests that these are repair cells (20 August, p 8). Could there be an alternative or additional purpose, such as rewiring to change maternal behaviour? Something similar occurs in insects infected with certain parasites, though I am unaware of this occurring in mammals.
Pig-human danger
Your article on using pig-human chimeras to treat Huntington’s disease is astounding in its complacency (13 August, p 10). The procedure it describes raises the risk that new diseases might cross the species barrier to become uncontrollable epidemics. So who has done the risk-benefit analysis that allows the researchers you quote to say that “the benefits of a cure outweigh such concerns”, when the treatment will benefit only a few thousand people in the west?
There is little reassurance in the statement that the transplants will come from “clean” pigs. This is a marketing term, not a technical one: you can’t screen for what you don’t know exists.
As recently as 13 January 2004, a news item on New 杏吧原创‘s website reported: “Pigs grown from fetuses into which human stem cells were injected have surprised scientists by having cells in which the DNA from the two species is mixed at the most intimate level… ‘What we found was completely unexpected. We found that the human and pig cells had totally fused in the animals’ bodies,’ said Jeffrey Platt, director of the Mayo Clinic Transplantation Biology Program…Importantly, the team also found that porcine endogenous retrovirus (PERV), which is present in almost all pigs, was also present in the hybrid cells. Previous laboratory work has shown that while PERVs in pig cells cannot infect human cells, those in hybrid cells can. The discovery therefore suggests a serious potential problem for xenotransplantation.”
Back-to-front safety
The seat anchors in an aircraft like the Airbus that ran off the runway at Toronto’s airport in early August can, we are told, withstand a 16-g deceleration (13 August, p 4). This figure is superficially impressive, but on closer examination it is less than reassuring.
Under 16-g deceleration, a force equal to a weight of approximately 1.5 tonnes is transferred by the safety belt to the passenger’s body, and this could lead to severe or lethal mutilation. It seems obvious that the seat ought to be turned around so that the passenger leans back in the direction of deceleration.
Proposing this design improvement would undoubtedly meet strong and tenacious opposition, and therefore be ruled impracticable. I suggest, however, that it is no less practicable than banning smoking in public places, which met strong and tenacious opposition and was therefore considered impracticable not long ago.
Abuse or infection?
I applaud the finding by the English court of appeal that the triad of brain swelling, subdural haematoma and retinal haemorrhage is not in itself enough to prove that infants have been abused (30 July, p 6).
I was surprised, however, that no mention was made in the court’s judgement about bacterial toxins and other toxins as a possible cause of infant deaths. There is considerable evidence that the signalling cascades initiated by various toxins can drastically reduce the antioxidant levels in the brain and its vasculature. Depletion of brain antioxidants, in particular ascorbate, has in turn been clinically linked to a weakening of the brain vasculature and all of the pathological symptoms in the triad. In children suffering such depletion, even innocent handling or what would otherwise be uneventful knocks could be enough to damage vasculature.
It is even possible that the effects of toxin signalling themselves rapidly produce all of the pathological changes seen in the triad. Whether this actually happens nobody knows, because the pathology testing to assess the levels of ascorbate, toxins and cytokines in blood and various organs is simply not done, either when children are first seen by a doctor or at autopsy.
The involvement of toxin signalling in some supposed “shaken baby” cases remains a tantalising prospect because toxin signalling is now well established as a major factor in the pathophysiological changes found in the victims of sudden infant death syndrome (SIDS). Many of the changes seen in SIDS cases are also evident in alleged shaken baby cases, so it would seem prudent to perform the appropriate pathology tests.
Deafening whales
Your article suggests that seismic surveying for oil “could chase whales from breeding or feeding grounds, or make it difficult for dolphins to hear the sonar they use to catch fish” (20 August, p 14). It compares the sounds of the air-gun arrays used to map the seafloor with the noise made by navy sonars that have been implicated in strandings of beaked whales.
However, the problem is not simply the amount of noise involved. Military echo sounders of the kind implicated in mass strandings of whales put out more than 235 decibels in water in pulses that can last for several seconds in a beam around 30 degrees wide, oriented more or less horizontally. Whales are affected in three ways by these sonars. First, the very long pulses make the sonar system likely to produce temporary threshold shift (TTS) levels in hearing in marine mammals, and for the noise to be perceived as “loud”. Over an extended period, TTS produces permanent threshold shift in hearing, or deafness.
Secondly, the more or less horizontal orientation of the focused sound beam means that the sound travels long distances close to the surface of the water, where whales spend most of their time. Thirdly, the speed at which naval vessels travel means that large areas 鈥� and, therefore, potentially large numbers of animals 鈥� can be affected in a short time.
While air-gun arrays used by the oil industry may produce more intense sound (as much as 256 decibels in water), the pulses last less than 200 milliseconds, and this reduces the potential for TTS. Further, the very high source levels quoted are in fact a “virtual” figure produced by the sum of the sound from the many small individual guns in the array; nowhere are there sound levels as high as the maximum figure quoted for an array.
Evidence from areas that are heavily surveyed by marine seismic vessels, such as the Gulf of Mexico and the continental shelf around the British Isles, shows that whales remain abundant even during surveys, though they tend to keep away from the vessels that are actually conducting them.
A review by the Scientific Committee on Antarctic Research, of which I am executive director, concluded that the risk to marine mammal populations posed by an individual air-gun survey was likely to be small, and significantly less than the risk posed by some naval sonars. Noise generated by human activity does have some potential adverse effects on whales, but they are not as clearly demonstrated as your article implies.