Yesterday was cold and wet out, and in fact, it actually snowed for a few minutes around 10 am, so I stayed in and caught up on my reading. Too bad the snow was so ephemeral, as I wanted to photograph it. The top of my RV’s “porch” awning iced up in the brisk wind, though.
A layman’s article in the journal Science (Australia to test ‘mosquito vaccine’ against human disease, 10 Dec. 2010, vol. 330, p. 1460-1461) discusses a fascinating approach to dealing with mosquitoes carrying serious diseases of humans. The idea is to infect mosquitoes with the bacterium Wolbachia pipientis, which has the ability to keep mosquitoes from being infected by human-disease organisms. The Australians have succeeded at infecting the vector of dengue, Aedes aegypti, with Wolbachia in cage trials, and now plan a field test in Australia. If successful, they want to try it next in Vietnam and then possibly Thailand. Dengue is a viral disease in humans that causes crippling joint and muscle pains, so the possibility of eliminating it is exciting.
Wolbachia has a very effective way to spread rapidly within a population. All infected female mosquitoes pass on the bacterium to their young, but when uninfected females mate with infected males, there are no viable young. It took only two decades for Wolbachia to infect a fruit fly species, Drosophila simulans, around the world.
The article stated that Wolbachia-infected mosquitoes are resistant to causative agents of some other important diseases, namely elephantiasis and chikungunya, and even inhibits some species of Plasmodium parasites that cause malaria. Unfortunately, the major disease-carrying mosquito species are not infected by Wolbachia, so the Australians want to give Wolbachia a boost up. No genetic engineering is involved and the bacterium already exists widely in the wild, so researchers believe that environmental concern re the release will be minimal.
Some mosquito species carry Wolbachia and do not carry human diseases whereas other mosquito species do not harbor the bacterium but do carry human diseases. This being the case, it begs the question of why Wolbachia does not already infect disease-carrying mosquitoes. Is it possible that the disease organisms of those mosquito species have already evolved ways to defeat Wolbachia?
There’s another interesting article in the 12 November 2010 (vol. 330, p. 932) issue of Science entitled “A wandering mind is an unhappy mind.” Yep, that’s really the title of a serious research paper in one of the world’s most prestigious scientific journals, and it caught my eye and I bet you know why.
There were three basic findings. First, people’s minds wander frequently almost regardless of what they are doing. Second, people are less happy when their minds are wandering than when they are not. Third, what people are thinking is a better predictor of happiness than what they are doing. The authors stated, “… a human mind is a wandering mind, and a wandering mind is an unhappy mind.” You could bring up the Devil and idle hands if you want to, but to me it rather sounds like Mother Nature giving us yet another insistent incentive to do better. Not a bad thing to realize a few days before the New Year.