February 2007 – Page 3 – David Bradley

H5N1 in the UK

UK government vets have confirmed infection with the H5N1 strain of avian influenza in 2600 turkeys that died on a Suffolk farm owned by the Bernard Matthews company. The 159,000 turkey flock will have to be culled with all the risks that entails to prevent the disease spreading further.

According to a statement from the European Commission a protection zone of 3 km radius and a 10 km surveillance zone will be established around Holton, a village about 25 km south-west of Lowestoft.

This is the first time H5N1 has been identified in the UK on a commercial property. A previous outbreak of avian influenza was H7 that required a cull of 50000 fowl to be culled.

There are fifteen known variants of avian influenza. The most virulent, and usually fatal in birds, are H5 and H7 strains. There are then nine variants of the H5 strain and the type of most concern because of the risk to human health is H5N1. While H5N1 can be fatal in humans it has not yet mutated into a form that can be transmitted from person to person.

According to virologist John Oxford of the Queen Mary College, University of London, “I don’t think it has made any difference as a threat to the human population.”

Meanwhile, Channelnewsasia.com today reports yet another outbreak of H5N1 in Japan, the fourth this year.

Negative refraction

Light at the end of the tunnel “Can visible light ever be manipulated so that it bends the wrong way?” asks Katharine Sanderson in Nature. She suggests that successfully reversing light by making a negative refraction material could open up the possibility of some rather futuristic devices, such as microscope lenses that can resolve objects smaller than the wavelength of light or the much-desired invisibility cloak.

Sanderson reveals that Jennifer Dionne and Henri Lezec, working in Harry Atwater’s group at Caltech have made a material with a negative refractive index for visible light. The findings were announced at Nanometa 2007 in Seefeld, Austria, but are yet to be peer-reviewed for publication.

The only caveat is that Dionne and Lezec have only demonstrated the effect with a two-dimensional system. Does that count as true negative refraction, asks Sanderson? She quotes Atwater as explaining the options of upgrading to 3D: “Atwater envisages stacking a dense array of waveguides on end: “We have not done this yet, but at least this work illustrates the inherent possibility of doing so.”

Let’s hope so, I really fancy one of those invisibility cloaks.

A Good Delusion

Evolutionary biologist Richard Dawkins continues to wow them Stateside with his book The God Delusion. Recently, he appeared on Stephen Colbert’s show to discuss the fundamantal differences between a rational scientific perspective of the universe and the nature of reality and the irrational viewpoint Colbert supports.

Dawkins, with good humour, attempts to argue his corner with Colbert who stubbornly insists that invoking God provides a much simpler explanation of the universe and man’s place in it than a Big Bang and Darwinian evolution. Dawkins points out that, “You get to complex like a human being by slow gradual degrees, and that’s the only ultimate explanation that will work. You can’t just suddenly magical complex things like God into existence,” he adds.

Life is not due to random chance, that’s the one thing it isn’t, because Darwinian natural selection is the exact opposite of random chance, it’s a highly non-random process, Dawkins further explains, “The big thing that everybody misunderstands about Darwinism is that it’s not an accident, it’s too complex to be an accident.”

Egg in a Bottle

Egg in a bottle Ever fancied squeezing an egg into a bottle? No? Well, it’s a kind of perennial physics demonstration that science teachers the world over love to do. I could simply describe how to do it and the results you might expect, but that would be no fun at all. Instead, I spent a good ten minutes scanning videos on the net where individuals attempted to carry out this experiment, some of them more successfully than others. Most handling naked flames and solvents (methylated spirits and the like) in a non-laboratory setting with absolutely no safety equipment (not even goggles) in sight.

More importantly though, most of these experimenters managed to get most of the egg in the bottle, but usually the egg split and simply splurted into the bottle rather than squeezing through the neck and plopping into the bottle intact.

In this video, the “researchers” succeeded in getting a nice squeeze and plop (far better even than the Brainiac team in their attempt).

The key to their success is apparently using a bottle with a nice wide neck. Most of the other videos try to use a beer bottle or something similar which constricts the egg as it squeezes through the opening and splits it.

So, how does it work? What mysterious force is pulling the egg into the bottle? Well, the answer is there is no mystery it is simply air pressure pushing down on the egg. But, wait a minute, what’s the burning paper got to do with air pressure?

Okay, here’s the short of it. Dropping a burning spill (or burning piece of paper into a bottle) and the air in the bottle will quickly expand and a small volume escapes. When the hard-boiled egg (with the shell removed) is placed into the opening, the spill goes out, the remaining gas cools and contracts and the greater outside air pressure pushes the moist flexible egg into the hole nicely.

If you use a nice moist egg and a bottle with a wide enough neck you’ll get a nice squeeze and plop. Anyone who has a use for a hard-boiled egg covered in burnt paper stuck in a bottle is welcome to contact us at Sciencebase with their ideas. Additionally, if you know how to get the egg out again without breaking the bottle leave us you thoughts in the comment form.

Bottled seaside air

Seaside Beach Huts Bottled seaside air! It almost sounds like a scam from the Victorian era when the bracing “ozone” of fresh air at the British seaside was said to cure all kinds of ailments and led to a boom in seaside resorts and continues to ebb and flow.

But, it’s not a scam. Researchers at the University of East Anglia have been plucking bacteria from the North Norfolk coast at a little village called Stiffkey (pronounced Stoo-Kee) and fermenting them to reproduce the marshy smell of the seaside in the laboratory.

Andrew Johnston and his team isolated the bacterium from the mud at Stiffkey saltmarsh and have identified the single gene responsible for the emission of the strong-smelling gas, dimethyl sulfide (DMS).

“On bracing childhood visits to the seaside we were always told to “breathe in that ozone, it’s good for you’,” said Prof Johnston. “But we were misled, twice over,” he adds, “First, that distinctive smell is not ozone [a highly toxic allotrope of oxygen], it is dimethyl sulfide. And secondly, inhaling it is not necessarily good for you.”

DMS is a little known but important gas. Across the world’s oceans, seas and coasts, tens of millions of tonnes are released by microbes that live near plankton and marine plants, including seaweeds and some salt-marsh plants. The gas plays an important role in the formation of cloud cover over the oceans, with major effects on climate.

Intriguingly, DMS acts as a homing scent for seabirds, almost like the odour of Brussels sprouts at a festive dinner table – it helps birds sniff out food in the lonely oceans, even at astonishingly low concentrations. Understanding the role of microbes in producing this key chemical is important in understanding a whole range of ecosystems.

The discovery adds to the diverse list of Stiffkey’s claims to fame. The small coastal village is renowned for its ‘Stewkey Blue’ cockles and was also the home of Henry Williamson, author of “Tarka the Otter”. It’s also known for its infamous rector, Reverend Harold Davidson, who was defrocked in 1932 after allegedly “cavorting with” London prostitutes. The pronunciation of the village’s name itself is even controversial with the older locals preferring the archaic Stoo-Kee, while the incomers often prefer the posher sounding and phonetic Stiff-Key. (Incidentally, my photograph of beachhuts at the head of this article was taken along the coast at Wells-next-the-Sea.