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Past Shows
May 31, 2008
 Download an MP3 of the entire program (22MB).
Pterosaurs Walk the Walk
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Giant azhdarchid, eating baby dinosaurs for lunch. Credit: Mark Witton
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Our traditional view of pterosaurs, a type of prehistoric flying dinosaur, included the idea that they lived and hunted much like modern-day gulls or sea hawks: swooping out of the sky to snatch fish from oceans or lakes. But Mark Witton, a PhD student in the Department of Earth and Environmental Science at the University of Portsmouth in England, and his colleagues, have come up with a radically different view of one kind of pterosaur, the Azhdarchid pterosaur. They claim these giant predators actually preferred to walk on land, and snacked on baby dinosaurs and other small animals. Azhdarchids include the largest of all pterosaurs: some had wingspans exceeding 10 metres and the biggest ones were as tall as a giraffe.
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Two-mom Albatross Families
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There may be a lot of debate over same-sex parenting among humans, but among Laysan albatross, it's the sensible solution when faced with a shortage of males. Lindsay Young, a Canadian PhD. student at the University of Hawai'i, had been studying the nesting habits of these large sea birds, when she discovered a high proportion of nests with two eggs. This struck Ms. Young as odd since albatross generally only lay a single egg. Since it's nearly impossible to tell the sex of an albatross merely by looking, Ms. Young ran some genetics tests and, to her surprise, discovered that 30 percent of the bird couples were comprised of two females. It seems to be a clever way of dealing with a shortage of males. The females birds copulate with a male but then pair up to raise a baby bird together. It's an egg-cellent survival strategy since it takes two adult albatross to raise a chick.
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Robo-monkey
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Monkey See, Monkey Do, courtesy of Nature Magazine |
Robot monkey arms -- it may sound like a B-grade sci-fi movie or a hard-core punk band. But it is, in fact, the cumulative result of 25 years of research for Dr. Andrew Schwartz. Dr. Schwartz, a neurobiologist with the University of Pittsburgh, has developed a robotic arm that can be controlled solely by the brain signals of a rhesus monkey. The monkeys learned to control the arm first with a joystick, in order to feed themselves. Then the arm was hooked up to their brain with a small array of micro-electrodes and, with some practice, they learned how to feed themselves with the arm, controlling it entirely with their mind. Dr. Schwartz's research has exciting applications for patients with prosthetic limbs and spinal cord injuries.
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Biochar - Black is the new Green
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Ordinary amazon soil (left) and Terra Preta - courtesy Bruno Glaser |
Thousands of years ago, Amazonian farmers plowed charcoal into their land to increase its fertility, creating Terra Preta, or black earth. Today, researchers are learning from these prehistoric farmers to make a new kind of black earth that will increase the sustainability of farming and provide a way to reduce atmospheric carbon dioxide and global warming.
Dr Marco Rondon, a geochemist from the International Development Research Centre in Ottawa, has investigated Terra Preta soils. He's also run a long-term project in Colombia enhancing poor soils with charcoal, or bio-char, to create new black earth. He's found that the charcoal significantly increases the fertility of poor soils, and could provide significant benefits to poor farmers, especially if they're rewarded for storing carbon, in the form of bio-char, in their land.
Dr. Johannes Lehmann, a professor of soil Geochemistry at Cornell University, says that this happens because the bio-char acts as a kind of superior organic material in the soil, retaining nutrients and improving conditions for plant growth. Dr Lehmann also says that soils can absorb large amounts of bio-char, which can last in soils for hundreds or thousands of years, thus providing a simple way of locking up carbon from the atmosphere.
Dr. Robert Brown, a mechanical engineer and the Director of the Center for Sustainable Environmental Technologies at Iowa State University, has found that biomass energy production, and biochar for agriculture, dovetail nicely. In his high-tech biomass energy systems, he turns agricultural wastes into flammable gasses and bio-oils, which can substitute for fossil fuels. Biochar is a by-product of this process and his agronomist colleagues are spreading it on cornfields to return nutrients to the soil and lock away carbon.
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Science Fact or Science Fiction: Catching a Cold
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And now, another episode of our occasional feature, Science Fact or Science Fiction. From time to time, we present a commonly held idea or popular saying - and ask a Canadian scientist to set us straight on whether we should believe it or not.
And today’s statement is certainly one we’re all familiar with:
A cold quits being infectious before the symptoms go away.
For the scientific lowdown, we go to Dr. Arlene King, Director General of the Centre for Immunization and Respiratory Infectious Diseases, at the Public Health Agency of Canada in Ottawa.
Theme music bed copyright Raphaël Gluckstein. Creative Commons License by-nc-nd-2.0
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