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After one of his college roommates succumbed to the disease during a trip to Africa, Szabolcs Márka became concerned about the impact of malaria on the peoples of that continent. Now a physicist at Columbia University, Márka has been using his expertise to develop a means of combating that plight. He’s using lasers to restrict the movements of disease-carrying mosquitoes:
“People concentrate more on studying mosquitoes’ olfactory or chemical sensors, but light or heat seemed like an interesting area,” he says. “Overloading, damaging or confusing this sensory system can prevent mosquitoes from reaching their prey.”
On a recent day in his lab in Pupin Hall, Márka placed mosquitoes in a test chamber through which he and his team shot an infrared light ray. The mosquitoes, unaware of the barrier, flew toward it but stopped and turned back upon reaching it.
Márka hopes that his research will someday lead to the development of an effective laser-based mosquito barrier that can be used in regions of the world heavily afflicted by malaria.
Link (warning: self-starting video) -via Ace of Spades HQ | Image: Columbia University
Medical researchers have discovered that an inexpensive deworming pill that has been used in Africa for more than 25 years can kill mosquitoes. The medicine, known as ivermectin, is effective for only a month. So it’s necessary for everyone in a region to take it at the same time. But when administered that way, the incidence of malaria can drop by 80%:
They vacuumed mosquitoes from the walls of huts in three villages whose inhabitants had recently been given ivermectin and three whose had not, and tested to see how many mosquitoes contained malaria parasites.
The ivermectin villages had almost 80 percent fewer.
The drug was shortening the mosquitoes’ lives, explained the lead author, Brian D. Foy, a Colorado State mosquito expert. Only older insects transmit malaria, since they must get it from humans first.
Link -via Glenn Reynolds | Photo by Flickr user wild_turkey5300 used under Creative Commons license
It’s skeeter season (at least here in Oklahoma) and while everyone has their preferred method of avoiding malaria and dengue fever–and the general annoyance of being vampirized by flying insects–there are some really bad ideas about how to do so. DIY Life has a list of legitimate tips and debunks some common myths about mosquito control. Example:
A popular email forward from a few years back states that if you spritz yourself with a 10 to 1 mix of water to Listerine, you’ll repel mosquitoes. While the menthol and eucalyptus doesn’t appeal to the critters, the dilution won’t be enough to make much of a difference. (And directly applying Listerine to skin will just dry you out.)
Link | Image: Wikimedia Commons
For the first twenty seconds, she bores her way in. Then she starts to tank up, and her body swells with blood. This is an everyday event, but it’s so fascinating at this close-up view.
via First Things
Scientists at the University of Arizona have created mosquitoes that are completely safe from the parasite that causes malaria. It does so by reducing the lifespan of the engineered mosquitoes. Most mosquitoes live only two to three weeks, but the parasite needs twelve to sixteen days to develop inside a mosquito. Consequently, these mosquitoes don’t live long enough to become dangerous.
So with that problem solved, how can scientists use the new mosquitoes to destroy malaria? At Popular Science, Laurie J. Schmidt explains:
According to Riehle, completely eradicating the malaria parasite carried by mosquitoes requires three things: the ability to engineer the mosquito, finding genes or molecules that can kill the malaria parasite, and giving the modified mosquitoes a competitive advantage so they can replace the wild population. The first two components have been accomplished, but Riehle says the third represents a bigger hurdle. “A lot of research is being done now to give the mosquitoes fitness advantages so that they can replace the wild populations,” he said. “But it’s probably at least a decade away, and if this is ever used for malaria control it will take several years for population replacement to actually occur.”
Link | Photo by John Tann used under Creative Commons license | Malaria Vaccine Spread Through Mosquitoes Themselves
It has been a question that has long perplexed people: why are some individuals seemingly immune to mosquito bites, while others suffer endless attacks?
Scientists at Rothamsted Research in the U.K. have made progress in identifying which of the approximately 300-400 chemical odors produced by the human body attracts or repels insects (insects have very keen sense of smell they use to guide them to their prey).
Using two groups of test subjects, one ‘attractive’ to mosquitoes and one ‘unattractive, the scientists were able to isolate and identify 7-8 distinct chemical odors which repelled mosquitoes. Some of these odors were thought to be related to stress.
Dr. Logan and his team have found only a small number of body chemicals—seven or eight—that were present in significantly different quantities between those people who were attractive to mosquitoes and those who weren’t. They then put their findings to the test. For this they used a so-called Y-tube olfactometer that allows mosquitoes to make a choice and fly toward or away from an individual’s hand. After applying the chemicals thought to be repellant on the hands of individuals known to be attractive, Dr. Logan found that the bugs either flew in the opposite direction or weren’t motivated by the person’s smell to fly at all.
The group’s latest paper, published in March in the Journal of Medical Entomology, identified two compounds with “significant repellency.” One of the compounds, 6-methyl-5-hepten-2-one, is a skin-derived compound that has the odor of toned-down nail-polish remover, according to George Preti, an organic chemist at the Monell Chemical Senses Center in Philadelphia, who is involved in a separate line of research into insect-biting behavior. The other, identified in the paper as geranylacetone, has a pleasant odor, though there is some question about whether the chemical is formed by the human biochemical process or is picked up in the environment, Dr. Preti says.
From the Upcoming 
ueue, submitted by Geekazoid.
(Illustration: Michael C. Witte)
