Poor get poorer
As always, given the inequities built into the global economic system, the poorest people in the world have been the…
The dynamics inside any fruit fly room are as riveting as a reality TV show. Some Drosophila strains are bullies, while others are just out to mate; some spend more time chowing down; and some are more dedicated to grooming themselves. A decade ago, studying these complex behavioral dynamics was a tedious task, requiring hours spent watching fuzzy videos of flies being flies, jotting down their every action and the time it occurred.
“The problem was that, not only was this prohibitively time-consuming and mindless, but the behaviours were fairly subjective and people would categorise them differently,” says biologist Benjamin de Bivort of Harvard University.
Now, that&’s all changing. With the plummeting cost and rising quality of high-definition cameras, sensors and machine-learning programmes, biologists are using computers or touchpads to automate the detection of fly behaviours, from grooming to mating — even detecting how often they eat. Today, such methods are so sensitive that they can reveal the individual motion of each of the six legs of a Drosophila.
“There&’s a revolution happening in behavioral neuroscience that comes about because of all these cheap sensors designed for phones and personal electronics,” says de Bivort.
These new techniques are giving scientists the tools to integrate quantitative behavioral data into studies of neuroscience, ageing and even metabolism —zeroing in on the neurons responsible for different fly behaviours, for instance, and how neurodegeneration or obesity changes those neurons’ activity.
“This isn’t just a tool to make experiments go faster,” says David Anderson, a neurobiologist at Caltech. “We’re trying to take a field that&’s been defined by people sitting in the jungle with a notebook and make it objective and quantitative.”
SARAH CP WILLIAMS/THE SCIENTIST
Cut sleeping sickness
A new method for making chemicals that lure tsetse flies to traps has been developed. It uses a cheap by-product from the cashew nut industry as its starting material, so the discovery may mean the flies — which carry sleeping sickness (also known as African trypanosomiasis) — can be trapped at a lower cost. The method, published in Green Chemistry last month, could offer a sustainable and more-affordable way to make two “attractant” chemicals: 3-ethylphenol and 3-propylphenol.
Many existing odour attractants are prohibitively expensive and not widely available in large quantities. It is possible to use buffalo urine, which naturally contains chemicals that attract the flies, as a substitute — though this has the downside of smelling rather unpleasant. Because the new method produces the attractants from cashew nut oil starting material, it may mean African countries could produce the chemicals locally. Cashew nut producers, which are widespread in Sub-Saharan African countries including Côte d’Ivoire, Nigeria and Tanzania, generate more than 300,000 tonnes of this waste product every year.
The liquid contains the chemical cardanol, which can be used to make both 3-propylphenol and 3-ethylphenol, through chemical processes developed by Lukas Goossen, a chemist at the University of Kaiserslautern in Germany who jointly led the research.
David Cole-Hamilton, a chemist at the University of St Andrews, UK, who also led the research, said the resulting attractant could be coated on a plastic sheet or similar surface, along with an ordinary insecticide. “The attractant lures the insects to the sheet where they are poisoned,” he said.
SCIDEV.NET
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