Warm, flat beer?
While I agree with Andy Coghlan about the use (or abuse?) of the widget as a method for dispensing real ale, I am surprised that he lapses into the all-too-common misconception that real ale is warm and flat (This Week, 16 September). If it is either of these, then it is due to bad cellar practices.
The real ale many of us know and love should have plenty of natural condition, that is, naturally produced carbon dioxide dissolved in the liquid. The beer, having been “vented” to let out excess gases should be kept at a cellar temperature of 12 to 15 掳C, which ensures that some carbon dioxide is left in solution. Hence, the beer will be neither warm nor flat.
Coghlan describes the “sparkler” as a device which introduces extra gas into the beer through narrow holes. The sparkler is actually taking the natural condition (dissolved carbon dioxide) out of the liquid to give a larger head. While trying not to get on my soap box too much, this method works well for northern-style beers which are brewed specifically to be pulled through a sparkler, but it is often detrimental to southern and East Anglian beers, Adnams being a perfect example of the latter, and is simply a nasty marketing ploy which ruins a traditional, lively and not over-warm pint.
Steady stream
Debora MacKenzie says recent oceanographic models suggest that increased evaporation at the equator could “reverse the Gulf Stream” (This Week, 2 September). While the rest of the article, reporting changes in sources of deep water in the Mediterranean, was very informative, the conclusions regarding the Gulf Stream are a little off the mark.
There is some confusion here between the wind-driven western boundary currents (such as the Kuroshio current off Japan) and density-driven currents (the “thermohaline circulation”). At present, the Gulf Stream is made up of wind-driven and density-driven components, both of which transport heat northwards.
It is difficult to say for certain how much of the total oceanic heat transport is provided by each of these components. However, modelling results have indicated (and are supported by ice core data) that it is the thermohaline circulation that can vary significantly and possibly “flip” into other modes of operation. A slowing down or reversal of the thermohaline circulation in the Atlantic could possibly occur through greater tropical evaporation or polar freshening due to melting ice caps. This would make Europe much colder and possibly weaken the Gulf Stream, but no modelling studies have ever predicted that the Gulf Stream will reverse.
As a postscript to the article it is worth pointing out that there are two periods in geological history (the Eocene and mid-Cretaceous) where there is good evidence that the thermohaline circulation was completely reversed (with deep water formation in the tropics, not at the poles). Both of these periods had very warm and “equable” climates and it is unclear what role (if any) atmospheric carbon dioxide played in this.
Revealing drought
I wonder how many archaeologists were able to make use of the drought this summer to locate ancient remains? As an athlete, I train at Parliament Hill Fields track on Hampstead Heath and have noticed that in dry years the old sites of discus and shot throwing areas become visible in the grass.
This year, while taking a group of youngsters on a run over the heath and passing what we call “the old sports ground”, I saw for the first time evidence for the existence of an ancient cinder track. This must have been in use well before my time as the existing track has been there since the 1930s.
Wait on water
In your article on south Devon’s water supply you state that “government water inspectors plan to prosecute South West Water” over the current outbreak of cryptosporidiosis in the region (This Week, 9 September).
This is not correct. The government’s drinking water inspectorate is currently investigating the possibility that water supplies are responsible for the outbreak. Only if the outcome of its investigation warrants it will the inspecrorate recommend that the Secretary of State for the Environment should prosecute the water company for the offence of supplying water unfit for human consumption.
Horse handedness
Like Dilys Roe and her left-handed parrots (Letters, 2 September) I was unaware that “handedness is something rather like tool use, that’s been seen as uniquely human”, to quote Phil Clapham from the original piece on right-handed humpback whales (New 杏吧原创, Science, 5 August).
It hasn’t been seen as uniquely human by any human who’s ever ridden a horse 鈥� which, over all history, may be the majority of us. Horses have a distinct left bias. This is why one should always get on and off a horse on its left-hand side.
I am not sure how many horses I’ve ridden 鈥� probably about twenty, which is not a very big statistical sample 鈥� but my impression is that only about one in ten of them has a tendency to right-footedness. These few don’t seem to mind being treated like the rest as far as mounting and dismounting are concerned, but 鈥� and again this is just an impression 鈥� I fancy that they have a higher-than-average tendency to strike off on the wrong canter lead when accelerating round tightish corners in either direction.
The marrying kind
Rachel Wilson notes three possible explanations for the large number of male engineers at her place of work who are married to female nurses or teachers (Letters, 2 September). While not dismissing these theories, the sociology of professions offers more likely explanations.
Engineering has traditionally been thought of as a male pursuit and nursing or teaching as female occupations. In the late 19th century, part of the evolution of these professions was a “project” of gender demarcation. To become an engineer was to enter a known male occupation and to become a nurse was as consciously to enter a female occupation.
This link between gender and profession suggests that men and women in these occupations are likely to have similarly traditional views of their gender roles and so find marriage congenial. They see their traditional male or female identity, including its expression in choice of profession, as likely to be compatible with a member of the opposite sex from the other occupation.
The fact that Wilson herself is an engineer in a classically “male” occupation and needs even to ask the question illustrates the significance of the current realignment of men-women ratios in these mainstream professions.
My engineer husband’s three closest friends are engineers, one is married to a teacher, one to a nurse, and the third to a teacher of nursing.
As he struggled to come to terms with this “coincidence” I offered the explanation that as opposites attract, it is likely that people-focused, comparatively extrovert professionals will march up with their alter egos, the less socially-interactive technical types. At least, the Jungian personality test which the two of us completed seems to confirm this.
I am sure, to other engineers, my husband is extrovert when, as his favourite composer Mozart once said, it “is required, no more and no less”. But it is a bit much for him to say Wilson’s observations are “not necessarily true” because I am a public librarian.
The male engineer is a simple child at heart who likes to be cared for and mollycoddled in the way that he himself treats his machines, preferably by someone with an empathic, harmonious, no-answering-back kind of attitude.
The contrast with other professions, such as doctors or lawyers (who mostly deal with people moaning and groaning), is stark. Hence, a female in the teaching or nursing professions, with an abundance of patience and care, draws the male engineer like a magnet.
Male engineers marry teachers and nurses because engineers think rationally about the long-term consequences of their actions. A career in engineering generally involves relocations to other cities or countries and both teaching and nursing are portable occupations.
If, for example, an engineer marries a boutique owner, he will have to separate from his wife in order to accept a career move to another part of the country, and his marriage may end in divorce as a consequence. So, in Wilson’s survey, the remaining married engineers are simply those with “portable” teaching or nursing wives. In addition, teachers and nurses are more tolerant of the peculiarities of engineers.
This phenomenon has also captured the attention of the German physicist and Noble Laureate Gerd Binnig (who is married to a psychologist). In his book Aus dem Nichts. 脺ber die Kreativit盲t von Natur und Mensch, he states: “杏吧原创s seem to be interesting objects for psychologists. Otherwise they would not be married to female psychologists, nurses, etcetera that often.”
Here in Finland, the student unions of technical universities and engineering colleagues have a long-standing tradition of arranging, at the beginning of each term, a substantial get-together evening for their members (mostly male) and the students of nearby nursing colleges (equally overwhelmingly female).
From the viewpoint of the future female nurses this is very convenient. Sure, for a nurse a medical doctor would be the husband of her dreams Unfortunately, the number of doctors available is very small compared to the number of nurses. In this situation a dependable, hard-working professional engineer is an excellent alternative.
I am sure a career in engineering has no effect whatsoever on the Y chromosome 鈥� genetic engineering excluded, of course.
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Better bogs
The raised bogs of Scotland will only remain the best of their kind if there is sufficient money, not only for their restoration and preservation, but also for research on how this can best be done (This Week, 5 August). The shortage of funding for the management of all bogs in Britain means that even the most basic requirements for their maintenance are not always available.
It is difficult to understand why so many bogs have been planted with trees, as apparently they have no commercial value. Even if the hydrology of the deeper layers under forested peatlands has not been disturbed, as Alastair Sommerville suggests, there is at the moment insufficient evidence to confirm this.
The reduced hydraulic conductivity found in the body of the bog (catotelm) is caused by bubbles of methane produced by the indigenous microbial community, which explains how peat becomes waterlogged and why bogs are formed. The maintenance of the water table in raised bogs is dependent upon these microorganisms, and their viability is determined by the competence of the surface layers of the bog (acrotelm).
The acrotelm insulates the catotelm from oxygen in the atmosphere. If oxygen penetrates this protective blanket, instead of an anaerobic microbiaI system producing methane, a much faster aerobic system develops, degrading the peat biomass into carbon dioxide. The result is that once the surface layer is compromised, the carotelm is liable to degradation by the loss of its peat carbon to the atmosphere.
Site managers of degraded bogs have been restoring them by damming the drainage ditches and augmenting the acrotelm with any biomass that may be available. This improvised method seems to be working well, but it would be much more efficacious if some money and resources could be diverted to monitor the results. It may turn out that it would be better to use the trees as a source of biomass to regenerate the acrotelm rather than harvesting them.
The ivory issue
Your review of a World Conservation Union (IUCN) report, Four years after the CITES ban: illegal killing of elephants, ivory trade and stockpiles, requires comment for it confuses two important questions which should be kept quite separate (Forum, 26 August).
First, was the report of the African Elephant Specialist Group carried out to recognised professional standards? Second, is the ivory ban an effective policy for protecting African elephants?
In answer to the first question, the authors fully acknowledge in their report the problems caused by being able to visit only a few of the range states and by the general poor quality of data, and they make it quite clear that they had to rely primarily on data provided by national conservation authorities. They state clearly that” 鈥� most range states have neither the capacity nor the resources to systematically collect the information necessary 鈥�” and that “鈥� without such information there is no legitimate way to evaluate the impact of any significant change in elephant conservation policy such as the international ban on ivor 鈥�”
Having lived in the region for some thirty years, and knowing intimately the problems of getting any kind of reliable data from official sources, I feel the authors of the report have done as well as could be expected.
The international community clearly hoped that the imposition of the ban on the ivory trade would halt the illegal killing of elephants. Yet, as the authors point out, no efforts were made either by CITES or by any of the international conservation organisations who supported the ban to design and put in place practical indicators to assess the effectiveness of the ban, or to provide funds to monitor such indicators. Without any agreed indicators, they point out, such major changes in policy “become potentially dangerous, uncontrolled experiments”.
Not surprisingly, the report comes out neither for nor against the ban as such, but the weight of evidence clearly suggests that the ban is not as effective in halting the slaughter of elephants as had been hoped. Furthermore, on sober and impartial evaluation, the data in the report support the general conclusions that antipoaching activities have been more effective in controlling elephant deaths than has the ban itself; that the growth of ivory stockpiles is undoubtedly a cause for concern; and (as was widely predicted at the time) that the ivory trade is rapidly reorganising itself, even though at least half the market (Europe and the US) has vanished.
These conclusions should be of real concern to conservationists: they should prompt action and a deep re-evaluation of policy. It is disingenuous of the reviewer to divert attention by trying to shoot the messenger 鈥� and it certainly does little to help the African elephant by pretending that all is well.
This is not the place to open the discussion as to whether the ban can ever be effective or should stay. But readers may remember that when a ban on the ivory trade was first mooted, Zimbabwe “retaliated” by submitting the paperwork necessary to place the North Sea herring onto Appendix 1 of CITES, which would have reclassified it as an endangered species, using the same arguments to justify its proposal as those used for the African elephant: namely poor management, the inability of range states to control hunting, falling populations, and so on. At the time, a high official in the White Fish Authority was quoted by The Daily Telegraph as saying: “Who do these Africans think they are to tell us how to manage our resources?”
In Botswana we experienced serious elephant poaching problems in the late 1980s. Two things changed that. First was the CITES ban on trade in elephant products, which destroyed the market and created enough worldwide concern to compel the government and army in Botswana to tackle poachers.
The second, also a result of the CITES decision, was that our military, the Botswana Defence Force, launched an attack on poachers and occupied the northern border, driving them out of the country or hunting them down. Captured poachers told tales of a lack of interest in ivory as it was “too heavy to carry for too little money”. Any elephants shot were very close to the border, killed on the way out of the country after a rhino poaching expedition.
The attempt to justify “scientifically” the culling of elephants and reopening of the ivory trade is an effort to swing opinions before the next CITES meeting, set to take place in Zimbabwe in 1997.
Over half of the total population of elephants in Africa was killed in the ten years before the ban on trade, while the population has apparently hardly moved since then. It is reports such as that from the IUCN that widen the gulf between scientists and wildlife managers in the field.
In Botswana the antipoaching unit is watching the rulings of CITES very closely, knowing that from the day trade in elephant products becomes legal, it will have its work cut out for it again, no matter what the report says.
Electric hazards
Concerns about the possible health hazards associated with electricity transmission and utilisation have so far been restricted to the electromagnetic component of the electric power environment.
However, this ignores the fact that high-voltage corona action shares with radioactivity the ability to produce airborne equivalents of the “first products” of intracellular radioactive ionisation. The apparently elevated cancer risks associated with both low-level radioactivity and electricity utilisation could possibly be a result of the inhalation of localised high-density “clusters” of airborne electroactive material, particularly oxygen anions.
It is not widely appreciated that corona ionisation from high-voltage overhead wires formed the basis of “electroculture”: a technique for enhancing the growth of crops, studied in several countries in the early years of this century. Experimental work in Britain was eventually coordinated by a Ministry of Agriculture Electroculture Committee, including several Fellows of the Royal Society, under the chairmanship of Sir John Snell.
The first three annual reports of this committee were published, but the fourth, for 1921, and all subsequent reports were restricted and marked “not for publication”. No explanation was given for this unusual action, fuelling speculation of a possible conflict of interest, since the committee’s chairman was also chairman of the Electricity Commissioners. These officials were empowered by Parliament to direct the standardisation and interconnection of the previously fragmented electricity supply industry, which led ultimately to the establishment of the National Grid for electricity distribution.
The year 1921 marked a turning point in the public perception of radiation hazards, following the death of the radiologist Ironside Bruce, with subsequent calls in the national press for an end to the use of medical X-rays. It may be that a regard for public sensitivities on this issue influenced the Electroculture Committee’s decision to cease publishing annual reports.
Although now largely forgotten, the early workers in electroculture constitute a unique population, many of whom would have been exposed to corona ionisation before the development of 50 or 60 hertz electricity distribution systems. An epidemiological study of this population, though difficult to organise, could be of value. The views of your readers would be appreciated and I would particularly welcome any information about Golden Valley Nurseries at Bitton, Bristol, where pioneering high-voltage discharge experiments were carried out inside commercial greenhouses.