The Pharmaceutical Journal
Vol 280 No 7484 p31
5/12 January 2008

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Oldest clone in the world

Bright classrooms hampering bright pupils

Wool and gabardine were effective in providing protection at high altitude

Oldest clone in the world

King’s Lomatia (Lomatia tasmanica) is an unusual plant that grows along the banks of streams in the cool, dense rainforest of the Tasmanian wilderness. A member of the Proteaceae family, it was discovered and named in the 1960s.

It is highly endangered and is found in only two tiny localities, the total population comprising approximately 500 plants. It is a spindly, straggly plant, growing up to five metres tall, with attractive leaves and clusters of tiny red flowers.

However, the plant is sterile, being unable to produce seed, and it is only able to reproduce by vegetative means, either by the production of root suckers or by branches falling off and taking root. The reason for this is that the plant is triploid, having three sets of chromosomes, and it is therefore impossible for it to reproduce sexually.

Work carried out by the University of Tasmania showed that there was no genetic variation whatsoever within the population. Even plants separated by more than one kilometre were identical. The entire population is composed of a single plant clone.

It is believed that this plant clone is the oldest known clone in the world, with fossils dated at 43,600 years old having the same shape and cell structure as the modern plant. If the ancient plant were not a triploid these would look different, as a sterile, vegetatively reproducing triploid cannot undergo any genetic variation.

Aside from the age of this clone, and its perilous position in terms of survival of the species, this discovery is fascinating because it shows that even without the flexibility of genetic variation, some plants are able to tolerate change. King’s Lomatia has lived through the major climatic change of the last Ice Age, and has survived the arrival of man in Tasmania.

Conservation groups have now set up a propagation programme, with the aim of making the plant commercially available to the public, in an effort to boost the population and range of the plant which, due to its small catchment, is prone to extinction through disease and fire.

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Bright classrooms hampering bright pupils

For children throughout the ages one of the most oft repeated admonishments from parents must be the advice not to read in bed by candlelight or torchlight after lights out as it will cause strain and damage to the eyes.

However, in a recent report by the British Educational Research Association (BERA), research carried out by professors from the universities of Essex and Cambridge found that, paradoxically, nine out of 10 classrooms studied were too brightly lit, causing headaches and problems with concentration.

The root of the problem lies with the type of lighting employed, usually low frequency (100Hz) fluorescent lights, which create an imperceptible flicker that causes headache and impairs visual performance.

The problem is often exacerbated by other factors, such as the introduction of interactive whiteboards, featuring video, animation, graphics and sound, on which the government has spent an estimated £50m, as a replacement for the traditional blackboard.

These whiteboards, combined with ceiling mounted data projectors, have the effect of reflecting light back at the pupils, resulting in an increase in overall light levels. Also, window blinds were often either incorrectly positioned, or damaged, reducing their effectiveness as a tool for controlling light levels.

These findings could explain why some children find reading easier when coloured overlays are placed on books, as they reduce the brightness of the page, improving comfort and performance of the task.

The researchers suggested replacing the 100Hz lights with higher frequency (32KHz) lights, used in approximately 20 per cent of the classrooms studied, which do not cause discomfort, and have the added benefits of using less energy and reduced operating costs.

They also recommended a greater use of natural light, controlled by properly functioning blinds, and adjusting the tilt of whiteboards, to reflect more light towards the ceilings and away from pupils’ eyes.

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Wool and gabardine were effective in providing protection at high altitude

There is a photograph of the party of George Mallory and Sandy Irvine’s 1924 expedition party shortly before their ultimately ill-fated attempt on the summit of Everest, one of the most striking features of which is the clothing worn by the group.

They are dressed in what appear to be tweed jackets with long woollen scarves tossed over their shoulders, and could easily be a group of friends about to embark on a Sunday afternoon ramble on the fells.

The clothes appear wholly inadequate for their role of keeping out the ravages of one of the most hostile environments on earth. Furthermore, these garments, especially when compared with the modern, high-tech clothing worn today, were long held to be one of the main reasons for the failure of the 1924 attempt.

Recent research, however, carried out using garments reproduced from samples of material from clothing found on Mallory’s body, discovered frozen on the north face of Everest in 1999, have shed new light upon this argument and have suggested that, rather than being inadequate, Mallory’s clothing was in fact highly effective in providing protection at high altitude.

The layered natural materials used to construct the garments were found to be excellent at trapping air next to the skin. The innermost layers were of silk, cotton and wool, while the outer layer of gabardine was hard-wearing and water-resistant yet breathable. Mallory’s clothing and footwear were 20 per cent and 40 per cent, respectively, lighter than modern gear — the lightest ever to be used on Everest.

The 1924 replica garments were tested directly against modern synthetic gear and the underclothes immediately felt warm, compared with a cold, clammy feel of the modern polypropylene equivalent. Also, as the clothes were made to measure, they did not ride up when stretching, and the whole ensemble felt of a piece when walking.

But the main difference was the degree of movement the clothing allowed. The traditional jacket has a pivot sleeve which allowed the arm to be fully extended when cutting steps in the ice, without displacing layers of warm air from the clothing, thus allowing quicker climbing.

The only drawback would have been fastening buttons with cold fingers and, since the clothing would have probably been put on at advanced base camp and left on for the duration, fly buttons would probably have been left undone because there would have been enough layers to interleave.

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