News
28 July 2022 – Five "and"s in a row
It's an old question: How can you have five "and"s in a row in a sentence that makes sense (semantically and syntactically)?
See News page for solution.
I covered it with a student yesterday, and we started looking at the sequence of numbers that can be formed by recursively performing the same action (or making the same mistake) required to make the sentence. The numbers increase quite rapidly: 1, 5, 21, 85, ...
I figured out how consecutive terms are related to each other (Tn = 4Tn-1 + 1) – in the process confirming I had 85 correct – then looked it up in The On-Line Encyclopedia of Integer Sequences. It's sequence A002450. I note the number of "and"s in sentences is not listed as one of the applications of the sequence.
22-02-2022 – Present situation
Sorry, my schedule is now reasonably full, so I'm somewhat unlikely to be able to accept new students. However, I do have a waiting list which every so often I manage to whittle back a bit, so enquiries are still welcome.
Ian.
31 July 2021 – the first international vaccination campaign
In 1803 the first international vaccination campaign was launched (literally – they used a ship) by a Spanish physician, Francisco Javier de Balmis, using cowpox to vaccinate against the deadly smallpox virus spreading in Central and South America.
Smallpox was highly contagious and had up to a 52% fatality rate, which is bad enough, but diseases don't just kill. In 18th century Europe, smallpox killed an estimated 400,000 people a year, and caused a third of all cases of blindness. Survivers were left badly scarred.
The vaccination technique discovered a few years earlier by Edward Jenner was effective, but cowpox only lasts in a test tube for 12 days, and there was a big ocean to cross.
To transport the cowpox virus to South America, de Balmis took 22 orphan boys, aged 3 to 10, selected by their carer and nurse Isabel Zendal, who insisted on accompanying them. (She also took her 9 year old son, so maybe only 21 of the boys were orphans.) The children were used as live incubators of the cowpox virus. Every ten days during the voyage, the virus was transferred from the pustules of two infected children to two healthy children, thus maintaining an unbroken strain across the Atlantic Ocean, visiting the Canary Islands, Puerto Rico, and Cuba on the way.
This may seem a somewhat barbaric way to transport a virus, but it was certainly the most practical method at the time. Cowpox was not life threatening, smallpox was.
The boys were left in Mexico, and from that country in 1806 a further 26 boys, aged 4 to 14, were collected for de Balmis' onward trip across the Pacific Ocean to Macau, Canton in China, and the Philippines. Meanwhile, José Salvany, deputy surgeon of the expedition, had gone south to what is now Venezuela, Panama, Colombia, Ecuador, Peru, Chile, and Bolivia. The vaccine was also carried north as far as Texas.
On his return journey to Spain in 1806 de Balmis offered the vaccine to the British in Saint Helena, in the middle of the Anglo-Spanish War (1804-1808).
As this article explains, "By the end of the campaign, about 300,000 people ... had received the vaccine for free." The mission was a success, and an extraordinary achievement.
Smallpox was officially declared to be globally eradicated in 1980. As for vaccines, we have it much easier now. Vaccines can be transported internationally without using orphans, they are safer than they've ever been, and it's easy to get a vaccine. Vaccines work.
By the way, Edward Jenner coined the words "vaccine" and "vaccination" in 1796 from the Latin for "of the cow". Isabel Zendal was recognised by the WHO in 1950 as the first nurse to take part in an international mission.
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