October 6, 2012 - Hooked On Fish * Risk-Taking Star Lives Fast * That's Not Cricket * Flight of the Phytoplankton * Prize Fight

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Next week, the Nobel prizes will be announced.  Winners will be modest, and losers will be graceful.  But according to one historian, beneath the veneer of collegiality lies a world of bitter rivalry and cut-throat competition, and we'll hear about it today. Before that, we'll talk to a young astronomer who's found a star that is orbiting dangerously close to a massive black hole; We'll find out how aging and ailing male crickets use false advertising to get a mate; and we'll hear how single-celled phytoplankton run for their lives. But first - how mosquito fish get hooked up.  

 

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Hooked On Fish
fish_hook.jpgA magnified view of the four-hooked genitalia.  Dr. Brian Langerhans

A new species of freshwater fish has been identified in Mexico.  The 20mm long mosquitofish is found throughout the country and had actually been seen before, but always assumed to be a different species of mosquitofish.  When Dr. Brian Langerhans, an Assistant Professor of Biology at North Carolina State University in Raleigh studied it closely for the first time, he was astounded, and knew right away he was looking at something very different.  The clue was the male genitalia.  It has four hooks, including one at the very tip.  Although more study is needed, it is believed the hooks are for latching on to the female to ensure the effective transfer of sperm.  The female is sometimes resistant to mating with males of lower quality, so the hooks allow the male to counter this response.
          
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Risk-Taking Star Lives Fast

black_hole_star.gifThe star designated S0-2 (yellow orbit) is the closest star orbiting our galaxy's central black hole.
One of the primary rules for survival in this universe is "avoid black holes."  Supermassive black holes, like the one at the centre of our galaxy, are notorious for being able to gobble up any matter, and nothing that falls within their event horizon can escape.  So, flirting closely with a black hole, like a newly discovered star announced this week by astronomers, is risky business.  The star was discovered by a team, including Dr. Tuan Do, a fellow with the Dunlap Institute of Astronomy and Astrophysics at the University of Toronto, using the Keck Telescope.  It orbits the black hole at the centre of our galaxy at a speed of 5000 km/s - more than 150 times as fast as the Earth orbits the Sun - and completes its orbit in just over 11 years.

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That's Not Cricket

Male crickets chirp as a way of communicating their fitness to a female.  The female is listening for both the quality and frequency of those chirps, as a way of determining the health of the prospective mate.  But a new study by Dr. Ken Fedorka, from the Department of Biology at the University of Central Florida in Orlando, has found that there are times when the male cricket is being deceptive.  The message he sends may not be truthful.  In an experiment comparing young and old males, both suffering from a pathogenic infection, scientists discovered a surprising difference in mating strategy.  Young infected males decrease their signal strength in favour of devoting more energy to fighting the infection, so they can mate in the future.  But old infected males increase their signal strength to deceive the female about health.  The deception is driven by a trade-off in the older male.  Instead of fighting the infection, energy is devoted to pursuing his limited opportunities for mating.   

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Flight of the Phytoplankton

FavellaHeterosigma2.jpgPredatory zooplankton (left) and its algal prey.  Photo credit: E. Harvey (GSO). Digital enhancement by C B Rubin.
On land, plants form the base of the food chain.  They absorb sunlight and CO2 to produce their tissues, and, to our great benefit, provide food for animals and oxygen to the atmosphere.  In the oceans, this role is filled by phytoplankton - a hugely diverse assortment of photosynthetic single-celled organisms that produce half the atmosphere's oxygen, and provide food for other marine organisms.  But Dr. Susanne Menden-Deuer, an Oceanographer at the University of Rhode Island, and her student Elizabeth Harvey, have found that phytoplankton can do something that land plants can't do.  They can run away.  In experiments, they demonstrated that these tiny microorganisms can somehow sense the presence of predatory zooplankton, and will avoid them by swimming away.  They think this might help understand more about the formation of algal blooms.
 

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Prize Fight

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This coming week, the Nobel Prizes for 2012 will be announced at the Karolinska Institute in Stockholm, Sweden. Achievements will be recognized in scientific fields, including medicine, physics and chemistry.  A Nobel Prize is prestigious; it brings fame and glory, a place in history, and, of course, money.  But the new book, "Prize Fight: The Race and the Rivalry to be the First in Science", chronicles a darker side to the famous awards.  The author, Dr. Morton Meyers, a Distinguished Professor of Radiology and Medicine at the State University of New York, describes the painful battles and even bitterly contested lawsuits behind some of the greatest Nobel-winning achievements, including research into tuberculosis, AIDS and MRI technology.    
 

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