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3 new ways to kill mosquitoes

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    (Mosquito buzzing)
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    (Swat)
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    Gotcha.
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    Mosquitos. I hate them.
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    Don't you?
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    That awful buzzing sound at night around your ears
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    that drives you absolutely crazy?
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    Knowing that she wants to stick a needle in your skin
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    and suck out your blood? That's awful, right?
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    In fact, there's only one good thing I can think of
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    when it gets to mosquitos.
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    When they fly into our bedroom at night,
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    they prefer to bite my wife.
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    But that's fascinating, right?
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    Why does she receive more bites than I do?
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    And the answer is smell, the smell of her body.
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    And since we all smell different and produce chemicals
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    on our skin that either attract or repel mosquitos,
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    some of us are just more attractive than others.
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    So my wife smells nicer than I do, or I just
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    stink more than she does.
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    Either way, mosquitos find us in the dark
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    by sniffing us out. They smell us.
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    And during my Ph.D, I wanted to know exactly
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    what chemicals from our skin mosquitos used,
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    African malarial mosquitos use to track us down at night.
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    And there's a whole range of compounds that they do use.
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    And this was not going to be an easy task.
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    And therefore, we set up various experiments.
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    Why did we set up these experiments?
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    Because half the world's population runs the risk
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    of contracting a killer disease like malaria
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    through a simple mosquito bite.
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    Every 30 seconds, somewhere on this planet,
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    a child dies of malaria, and Paul Levy this morning,
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    he was talking about the metaphor of the 727 crashing into the United States.
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    Well, in Africa, we have the equivalent of seven jumbo 747s
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    crashing every day.
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    But perhaps if we can attract these mosquitos to traps,
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    bait it with our smell, we may be able to stop transmission
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    of disease.
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    Now solving this puzzle was not an easy thing,
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    because we produce hundreds of different chemicals on the skin,
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    but we undertook some remarkable experiments
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    that managed us to resolve this puzzle very quickly indeed.
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    First, we observed that not all mosquito species
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    bite on the same part of the body. Strange.
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    So we set up an experiment
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    whereby we put a naked volunteer in a large cage,
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    and in that cage we released mosquitos
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    to see where they were biting on the body of that person.
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    And we found some remarkable differences.
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    On the left here you see the bites
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    by the Dutch malarial mosquito on this person.
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    They had a very strong preference for biting on the face.
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    In contrast, the African malarial mosquito
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    had a very strong preference for biting the ankles and feet of this person,
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    and that of course we should have known all along
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    because they're called mosqui-toes, you see? (Laughter)
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    That's right. (Applause)
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    And so we started focusing on the smell of feet,
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    on the smell of human feet,
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    until we came across a remarkable statement in the literature
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    that said that cheese smells after feet
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    rather than the reverse. Think of it.
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    And this triggered us to do a remarkable experiment.
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    We tried, with a tiny little piece of Limburger cheese,
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    which smells badly after feet,
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    to attract African malaria mosquitos.
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    And you know what? It worked.
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    In fact, it worked so well that now we have a synthetic mixture
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    of the aroma of Limburger cheese that we're using in Tanzania
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    and has been shown there to be two to three times
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    more attractive to mosquitos than humans.
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    Limburg, be proud of your cheese,
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    as it is now used in the fight against malaria.
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    (Applause)
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    That's the cheese, just to show you.
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    My second story is remarkable as well.
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    It's about man's best friend. It's about dogs.
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    And I will show you
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    how we can use dogs in the fight against malaria.
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    One of the best ways of killing mosquitos
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    is not to wait until they fly around like adults
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    and bite people and transmit disease.
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    It's to kill them when they're still in the water as larvae.
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    Why? Because they are just like the CIA.
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    In that pool of water, these larvae are concentrated.
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    They're all together there. They are immobile.
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    They can't escape from that water. They can't fly.
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    And they're accessible. You can actually walk up
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    to that pool and you can kill them there, right?
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    So the problem that we face with this is that,
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    throughout the landscape, all these pools of water
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    with the larvae, they are scattered all over the place,
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    which makes it very hard for an inspector like this
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    to actually find all these breeding sites and treat them with insecticides.
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    And last year we thought very, very hard,
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    how can we resolve this problem? Until we realized
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    that just like us, we have a unique smell,
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    that mosquito larvae also have a very unique smell.
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    And so we set up another crazy experiment,
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    because we collected the smell of these larvae,
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    put it on pieces of cloth, and then did something very remarkable.
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    Here we have a bar with four holes,
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    and we put the smell of these larvae in the left hole.
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    Ooh, that was very quick.
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    And then you see the dog. It's called Tweed. It's a border collie.
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    He's examining these holes, and now he's got it already.
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    He's going back to check the control holes again,
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    but he's coming back to the first one,
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    and now he's locking into that smell,
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    which means that now we can use dogs
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    with these inspectors to much better find
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    the breeding sites of mosquitos in the field,
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    and therefore have a much bigger impact on malaria.
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    This lady is Ellen van der Zweep. She's one of the best dog-trainers in the world,
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    and she believes that we can do a lot more.
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    Since we also know that people that carry malaria parasites
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    smell different compared to people that are uninfected,
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    she's convinced that we can train dogs
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    to find people that carry the parasite.
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    That means that in a population where malaria
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    has gone down all the way, and there's few people remaining with parasites,
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    that the dogs can find these people,
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    we can treat them with anti-malarial drugs, and give the final blow to malaria.
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    Man's best friend in the fight against malaria.
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    My third story is perhaps even more remarkable,
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    and, I should say, has never been shown to the public until today.
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    Yeah.
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    It's a crazy story, but I believe it's perhaps the best
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    and ultimate revenge against mosquitos ever.
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    In fact, people have told me that now they will enjoy
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    being bitten by mosquitos.
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    And the question of course is, what would make someone
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    enjoy being bitten by mosquitos?
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    And the answer
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    I have right here in my pocket,
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    if I get it.
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    It's a tablet, a simple tablet,
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    and when I take it with water,
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    it does miracles.
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    Thank you.
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    (Drinking)
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    Now let me show you how this works.
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    Here in this box I have a cage
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    with several hundred hungry
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    female mosquitos
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    that I'm just about to release. (Laughter)
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    Just kidding, just kidding.
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    What I'm going to show you is I'm gonna stick my arm into it
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    and I will show you how quickly they will bite.
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    Here we go.
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    Don't worry, I do this all the time in the lab.
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    There we go. Okay.
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    Now, on the video, on the video here,
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    I'm going to show you exactly the same thing,
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    except that what I'm showing you on the video
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    happened one hour after I took the tablet.
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    Have a look. That doesn't work. Okay. Sorry about that.
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    I'm sticking in my arm, I'm giving them a big juicy
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    blood meal, I'm shaking them off, and we follow them through time
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    to see these mosquitos get very, very sick indeed,
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    here shown in fast motion,
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    and three hours later what we see at the bottom
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    of the cage is dead mosquitos,
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    very dead mosquitos, and I'm going to say, ladies and gentlemen,
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    we have swapped the cards with mosquitos.
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    They don't kill us. We kill them.
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    (Applause)
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    Now — (Laughter) —
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    Maastricht, be prepared.
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    Now think of what we can do with this.
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    We can actually use this to contain outbreaks
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    of mosquito-born diseases, of epidemics, right?
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    And better still, imagine what would happen if,
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    in a very large area, everyone would take these drugs,
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    this drug, for just three weeks.
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    That would give us an opportunity to actually eliminate
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    malaria as a disease.
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    So cheese, dogs and a pill to kill mosquitos.
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    That's the kind of out-of-the-box science that I love doing,
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    for the betterment of mankind,
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    but especially for her, so that she can grow up
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    in a world without malaria. Thank you. (Applause)
Title:
3 new ways to kill mosquitoes
Speaker:
Bart Knols
Description:

We can use a mosquito's own instincts against her. At TEDxMaastricht speaker Bart Knols demos the imaginative solutions his team is developing to fight malaria -- including limburger cheese and a deadly pill.
(Filmed at TEDxMaastricht.)

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Video Language:
English
Team:
closed TED
Project:
TEDTalks
Duration:
10:20

English subtitles

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