The Pharmaceutical Journal
Vol 280 No 7500 p542
3 May 2008

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Didapper, hell-diver, dipchick or arsefoot

Feta — the friendly foreign food

It’s not that easy being green

Didapper, hell-diver, dipchick or arsefoot

Hello! Let me introduce myself. I am joining the group of pseudonymous correspondents who take turns to fill this page and I have chosen to use the moniker “Didapper”.

No doubt you are wondering why I picked that nom de plume. I know I am. So let’s read on and find out, shall we?

As a birder, I fancied an avian pen-name, and didapper happens to be an archaic synonym for one of my favourite water birds, the little grebe (Tachybaptus ruficollis), which has the habit of diving abruptly and popping up again suddenly, often yards from where it submerged.

The suddenness of its dive is recognised in its scientific binomial, which translates as “red-necked quick-sinker”.

But the word didapper also has a secondary meaning. It is an obscure pejorative term for someone who, like a little grebe, “disappears for a time and suddenly reappears” — something I did recently when the unexpected onset of serious illness took me off the radar for several months.

Didapper is by no means the only alternative name for the little grebe, although only one synonym, dabchick, is still in common use. Other names listed in W. B. Lockwood’s ‘Oxford book of British bird names’ include dap-, dip-, dob- and dopchick, along with dobber, dooker, ducker, devil-diver, hell-diver — and arsefoot.

Arsefoot? This ancient name, which was also applied to other types of grebe, derives from the fact that all grebes have their legs placed well to the rear. The word dates back to the end of the 16th century, when “arse” was a socially acceptable word for a tail or rump.

But let us return to “didapper”. Recorded variants on that name include dive-dapper and divedop. The word is derived ultimately from Old English dufedoppa, from dufan, to dive, and doppa, a diving bird. So literally, and also tautologically, a didapper is a dive-diver.

Incidentally, dabchick was until a few years ago the only word in the English language to contain the first three letters of the alphabet consecutively in the right order, but now it has been joined by the platelet aggregation inhibitor abciximab.

(Phew! I’ve managed to squeeze in a pharmaceutical reference at last. That should keep the editor happy.)

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Feta — the friendly foreign food

Gyppy tummy, Montezuma’s revenge, Gringo gallop, Aztec two-step, Delhi belly, Rangoon runs — call it what you will, the tourist trot is a common health problem for Brits holidaying abroad. We are susceptible because foreign foods may contain toxic micro-organisms to which we have not acquired any degree of immunity in our clean and pleasant land.

But for those travelling to Greece, at least, there may be way to avoid food poisoning — eat the local cheese. Researchers from the department of forensic and biomedical sciences at the University of Lincoln have found that feta cheese made from raw sheep milk contains friendly bacteria that produce natural antibiotics to kill off their food-poisoning cousins — the virulent organisms responsible for travellers’ diarrhoea and worse.

Studying feta made on small farms in Macedonia, northern Greece, the researchers isolated lactic acid bacteria that produce bacteriocins — peptides that inhibit the growth of dangerous food-borne pathogens, including the particularly nasty Listeria monocytogenes. Some strains of the friendly bacteria can produce up to three different bacteriocins to fight different food pathogens, the researchers found.

Surprisingly, the useful bacteria were identified as enterococci, which are most commonly experienced as virulent pathogens, often antibiotic-resistant, that cause problem infections in hospitals. As well as fighting food pathogens, the beneficial enterococci are also responsible for the unique taste of many Mediterranean cheeses.

Researcher Panos Chanos says that the useful strains of bacteria are able to grow in extreme conditions resembling those commonly found in foods, including the low temperatures of refrigerators and the salty conditions in cheeses such as feta.

“It is known that enterococci in general may have the same properties as good gut bacteria,” says Mr Chanos. “We hope our bacteria possess these properties too, so they could colonise our small intestine and fight listeria from within the body.”

The researchers say that further work may lead to the replacement of synthetic preservatives in foods by naturally produced bacteriocins, which may open up new opportunities for organic food production.

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It’s not that easy being green

Scientists have found that they can make green fireworks but they cannot make them green. Perhaps I can put that more clearly: researchers have formulated environmentally friendly pyrotechnic mixtures that produce displays in a range of colours, with the exception of one common hue that is still giving them trouble.

Lovers of fireworks have tended to overlook the fact that the combustion products are significant polluters of the environment. Conventional fireworks consist of a mixture of an oxidising agent and a reducing agent, together with additives such as binding materials, propellant charges and, of course, the agents that produce colours, smoke and sound to kindle the “Ooh! Aah!” reaction in the onlooker.

When a firework is let off, it releases a cocktail of poisons harmful to humans and the environment. These include heavy metals such as lead, barium and chromium, along with chlorates, dioxins and the nastier oxides of carbon, nitrogen and sulphur. Smoke and particles add a further health hazard.

Research chemists are now investigating the use of nitrogen-rich pyrotechnic compounds. These draw their energy not from oxidation but from the release of their high heats of formation. Candidate substances include derivatives of tetrazoles (rings made of four nitrogen and one carbon atom) and tetrazines (rings made of four nitrogen and two carbon atoms).

Aminotetrazole salts formed with non-toxic metals such as lithium, sodium, potassium, rubidium and caesium can be used to produce flames in a range of colours, including red, orange, violet, purple and pink — but not green. Researchers are now focusing attention on green-burning salts based on copper compounds as an alternative to the traditional barium salts.

Nitrogen-rich fireworks are not only eco-friendly but can also produce more oohs and aahs than traditional mixtures because they offer better colour quality and intensity, according to Thomas Klapötke of the University of Munich, Germany, who has written about them in the journal Angewandte Chemie.

The downside is that greener fireworks may have difficulty competing on price with established products. Professor Klapötke suggests that lawmakers should intercede to address the problem.

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