Pond Scum Power, There Goes the Neighbourhood, Bow Bug Shoots Itself, HIV History


 

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Pond Scum Power


algae.jpg From Wikimedia Commons

Pond scum may not be pretty to look at, but some scientists think it may be a beautiful solution to our energy needs. Over the past few years, we've devoted a lot of effort to developing biofuels from plant crops like corn and soy. But these crops take up lots of land and use a lot of water - resources we need for food production. It also takes a lot of fossil fuels to farm biofuels, so they're not nearly as green as we once supposed. Now the challenge is to find plants that don't need prime agricultural land and heavy irrigation to thrive.

Not a lot of plants are up to the challenge -- except perhaps for humble algae, better known as pond scum. Despite their diminutive size, some species of algae can turn sunlight and carbon dioxide into oil, which they store as fat reserves in their tiny bodies. This oil, in turn, can be processed into a biodeisel we can use in our cars. It sounds like a great idea and some scientists are convinced we can replace the fossil fuel we use with algal biofuel. But there are plenty of challenges before we start running on pond power. Researchers have only just begun to identify which species produce high amounts of oil and, then, getting them to do it reliably turns out to be kind of tricky. As well, designing large-scale algal farms turns out to be harder than it might sound. So, producing algal biofuel in the kind of volume that can satisfy our unquenchable thirst for fuel may still be a long way off.

  • Dr. Kirsten Heimann is the Director of the North Queensland Algal Identification and Culturing Facility at James Cook University in Australia. She and her colleagues are sifting through innumerable algal species in order to find which ones pump out the most oil. Dr. Heimann is particularly encouraged by one species she's found that produces 30 percent of its body weight in oil.


  • Dr. Al Darzins oversees the U.S. Department of Energy's National Bioenergy Center in Golden, Colorado. Dr. Darzins and his colleagues have recently re-started a U.S. government research program identifying oil-producing algae and trying to grow it on a large-scale.


  • Dr. Andres Clarens is an an Assistant Professor and an Environmental Engineer at the University of Virginia. He's interested in using waste CO2 from coal factories as a way of super-charging algal growth. As hopeful as he is that we'll be able to develop algal bio-fuel, he thinks, in the short term, large-scale algae farms will be best suited for sequestering carbon dioxide.


  • Dr. John Benemann is an independent consultant and research scientist who is somewhat skeptical that we'll ever produce algal biofuels in significant enough quantities that it will ever be a viable fuel alternative. However, like Dr. Clarens, he feels it has tremendous potential to act as an environmental sponge, not just for cleaning up the air, but as an efficient filtering system for sewage and waste water.

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There Goes the Neighbourhood


guillemots.jpg Guillemot colony - copyright Paul Glendell/Natural England

Seabird colonies are ordinarily noisy, crowded and messy, with thousands of birds perched on cliffs and ledges, laying eggs and raising chicks. They are, however, generally quite safe environments in which to raise a baby bird. So Kate Ashbrook, a researcher in the Faculty of Biological Sciences at the University of Leeds, was shocked when she saw things go bad in a colony of guillemots, known in Canada as murres. When food became scarce, and both parents had to leave the nest to forage, chicks were subjected to vicious attacks from other birds, and as a result, more than half the season's chicks were killed.


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Bow Bug Shoots Itself


froghopper.jpg Credit: Burrows et al., BMC Biology 2008

The tiny froghopper insect is a champion jumper - it can leap 100 times its own length, experiencing an acceleration of 400 times the force of gravity in doing so. Simple muscles, however, could never power such a fast leap. So Professor Malcolm Burrows and Dr. Gregory Sutton, from the Zoology Department at the University of Cambridge, decided to find out just how the froghopper does it. What they discovered is that the insect has evolved an internal structure built like a composite bow, with stiff and elastic materials. It uses muscles to draw the bow, and then releases the energy in it very quickly through the legs to power the leap. So the insect is not just the bow, it's also the arrow.


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HIV History


hiv_samples.jpg Tissues preserved in wax from Kinshasa - Credit: Dirk Teuwen

Canadian scientist Dr. Michael Worobey has spent much of the last decade combing Africa for evidence to reconstruct the origins of the HIV/AIDS epidemic. Most recently, he and his colleagues found one of the oldest samples of the virus ever discovered. It was from a 1960 pathology sample from an unknown woman in Kinshasa in the Democratic Republic of the Congo. The sample was preserved in wax, but retained fragments of the viral DNA. By comparing that fragment to another of similar age, and to more modern samples of the virus, Dr. Worobey and his group have been able to estimate when the virus first appeared in humans. It turns out to have been far earlier than had been expected - probably around the turn of the 19th century. That raises the question of just why the virus took so long to break out into an epidemic, and Dr. Worobey thinks it might have something to do with the rise of cities in central Africa. Michael Worobey is an assistant professor of ecology and evolutionary biology at The University of Arizona in Tucson.


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Theme music bed copyright Raphaël Gluckstein. Creative Commons License by-nc-nd-2.0