* Arsenic and Alien Life * Snakes With no #&%*$$!! Plane! * Sharks' Speedy Skin * Bendy-straw Barnacle Penis * Coloured Glass * Fact or Fiction: Coffee and Asthma *

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Arsenic and Alien Life

arsenic_microbes.jpg Microbes grown on arsenic - courtesy Jodi Switzer Blum
Life on Earth depends on a basic set of elements.  Carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorous.  These are the basic elements that are used to make DNA, proteins, and important chemicals vital for cellular metabolism.  Scientists have always wondered, though, if it might be possible to have life based on a different set of chemicals, either here on Earth or possibly "out there."  And the answer, as of this week, seems to be yes.  A group, including Dr. Ronald Oremland, a Senior Scientist at the US Geological Survey, in Menlo Park, California, has managed to cultivate a species of bacteria so that it uses arsenic instead of phosphorous in much of its basic chemistry.  It's a remarkable finding that surprised the scientists doing the work as much as anyone.  For the moment, they don't know very much about how the microbe is doing it, but it likely has much to do with the fact that this microbe is very arsenic-tolerant, (it was found in an arsenic rich lake in California) and that arsenic is chemically quite similar to phosphorous in some important ways.

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Addendum.  Since this story was broadcast there has been an unusual amount of debate about the results the group reported.  This will ultimately play out in the scientific literature as the methods and results are analyzed by the wider community, but for a taste of the criticism you might want to read this CBC News story.

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Snakes With no #&%*$$!! Plane!

flying_snake.jpg Paradise Tree Snake -- pre-flight, courtesy J Socha

Many people are frightened of snakes.  The idea of snakes slithering around on the ground beneath their feet just petrifies them.  Well, these Ohidiophobes are not going to be happy when they learn that snakes can fly, too.  Well, perhaps not fly, but glide with remarkable control and efficiency.  Dr. Jake Socha of the Department of Engineering Science and Mechanics at Virginia Tech in Blacksburg, Virginia, has been studying the small group of South-Asian snake species that have developed the ability to do a controlled glide from tree to tree and tree to ground.  By filming them, he's uncovered many of the tricks they use to accomplish this feat.  One key is that they flatten themselves from a tube into something closer to an airfoil, by spreading their ribs along the length of their body.  They also seem to slither through the air in order to achieve stability as they glide.

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Sharks' Speedy Skin

shortfin_mako.jpg Shortfin Mako shark - courtesy P Motta/University of South Florida

Sharks are well adapted predators, but we tend to think about those adaptations mostly in terms of attributes, such as sharp, gaping, powerful jaws.  In fact, they can be remarkable swimmers as well.  The Shortfin Mako shark has been reported to reach speeds of 70km/h and has remarkable maneuverability as well.  And to achieve this, it has a few notable adaptations to help it resist drag from the water it swims through.  Dr. Amy Lang, a Professor of Aerospace Engineering and Mechanics at the University of Alabama, has been studying the specialized scales these Mako sharks have on critical parts of their body that help it minimize drag from a phenomenon known as "flow separation."  She thinks copying the sharks' scales could help reduce the same king of drag on fast-moving objects, like helicopter rotors and submarines.

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  • Dr. Lang's research
  • Dr Lang's colleagues at the University of South Florida
  • News from the American Institute of Physics

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Bendy-straw Barnacle Penis

barnacle_penis.jpg Barnacle Penis, courtesy Matt Hoch
Barnacles are known to have very long penises - as long as ten times their body length.  But, as a PhD student in biology at the State University of New York in Stony Brook, Dr. J. Matthew Hoch discovered that the shape of barnacle penises varies, depending on their circumstances.  Barnacles grow a new penis every mating season, and by studying barnacles in both densely populated and sparsely populated configurations, he discovered that the length was the same in both groups.  However, sparsely arranged barnacles grew penises with more annulations - these are ringed folds like a vacuum cleaner hose or bendy-straw - that allow the penis to stretch across spaces to reach a receptive neighbour.

Related Links
  • Paper in Marine Biology
  • Dr. Hoch's web page
  • Essay by Dr. Hoch on the study of crustaceous genitalia

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Coloured Glass

coloured_glass.jpg Red, green and blue films. Photo credit: Kevin Shopsowitz
In an attempt to make a glass sponge to store hydrogen for hydrogen-powered cars, Dr. Mark MacLachlan, a Chemistry Professor at the University of British Columbia, 'accidentally' discovered a new type of glass film.  Using a new material consisting of nanocrystals of cellulose, the resulting glass film can reflect specific wavelengths of light, including ultraviolet and infrared.  One of several applications for this new glass is reducing the energy needed to cool buildings.  Windows could be treated with the glass film which would let light in, but reflect infrared light that creates heat.  There are also aesthetic applications.  By adjusting the amount of silica in the cellulose solution mix, the colour of the glass can be changed as required.  

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Fact or Fiction: Coffee and Asthma

This is 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.  

Today's popular belief is:"Coffee can ease the symptoms of asthma."  To help us settle the matter, we contacted Dr. Paul O'Byrne, Chair of the Department of Medicine at McMaster University in Hamilton, and a specialist in respiratory health. He says it is science fact.   

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