* Orca's Oral Obstacle * Bomb-Sniffing Plants * Pneumonia's New Genome * A Late Dinosaur * Fraser's Penguins *

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Orca's Oral Obstacle

orca_teeth.jpgOrca with worn teeth, courtesy Robin Abernethy, DFO
Marine biologists have been mystified by the wear and tear on the teeth of a particular group of killer whales.  This group is known as Offshore killer whales. They travel between Southern California and the Aleutian Islands and are often found along the continental shelf along Canada's west coast.  While other Orcas are known to eat sea mammals and salmon, the diet of this particular group wasn't known.  But Dr. John Ford, a Fisheries and Oceans' Marine Mammal Research scientist at The Pacific Biological Station in Nanaimo has been able to put two and two together and found that the offshore killer whale has a preference for Pacific sleeper shark.  The shark's skin is extremely abrasive and is embedded with rough scales called dermal denticles.  Apparently, tearing into these sharks takes a toll on the whale's teeth - they are often worn flat, right to the gum line, and the tooth's inner pulp is exposed.  However, these toothless whales may not be left to starve. Dr. Ford thinks it's possible that younger offshore killer whales, whose teeth are still functional, may share the kill with their dentally-challenged elders.

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Bomb-Sniffing Plants

plant_sniffers.jpg Before and after TNT detection, courtesy Colorado State U.
We're used to the high-tech security apparatus that surrounds us at places like airports these days:  metal detectors, closed circuit cameras and backscatter x-ray machines.  But soon the newest addition to our security systems might be the potted plants by the departure gate.  Dr. June Medford, a biologist at Colorado State University, is looking at recruited plants as bomb-sniffers.  She's re-purposed the chemical detection system that plants use to communicate among themselves.  So she's developed plants that react to the smell of TNT instead of other plants.  She's also connected this detection system to a genetic switch that makes the plant turn white when it detects the chemical.  The process is slow at the moment, but improvements to make it more effective are on the way, and other applications, like detecting pollutants, are on the horizon as well. 

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Pneumonia's New Genome

 Streptococcus pneumoniae bacteria, courtesy CDC
In a large international study, a group of scientists including Dr. Dylan Pillai, a Medical Microbiologist at the University of Toronto and the Ontario Agency for Health Protection and Promotion, have traced the evolution of an important human disease.  They studied Streptococcus pneumoniae, which is the primary cause of pneumonia, and can also cause sepsis and meningitis, and kills millions worldwide every year.  What they found was a remarkable evolutionary flexibility that has allowed the bacteria to change approximately 75% of its genome in just a couple of decades, and quickly adopt genes from the environment that can help it resist our drugs and vaccines.

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A Late Dinosaur

Alamosaurus.jpg Artist's reconstruction of Alamosaurus, copyright DiBgd

We all know that the dinosaurs went quickly extinct after a huge asteroid struck the earth, 65.5 million years ago.  However, if new research by Dr. Larry Heaman, a professor in the Department of Earth and Atmospheric Sciences at the University of Alberta, holds up, then we all might be wrong.  Dr. Heaman, a specialist in geological dating, used a technique not previously used on dinosaur bone, to date a leg bone from a giant sauropod dinosaur.  This bone had been found in sediments laid down after the asteroid impact, but it wasn't clear if this was because that's when the dinosaur died, or if the bone had been moved into those sediments after fossilization.  Dr. Heaman's technique seems to suggest the former, as his dating technique suggests this dinosaur expired 700,000 years after the big impact.

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Fraser's Penguins

Dr Bill Fraser has spent three and a half decades in Antarctica, studying its environment and animals, but especially the charming Adelie Penguin.  However, most of his recent research has been documenting the Adelie's decline in the face of changing Antarctic climate.  In his new book, Fraser's Penguins - A Journey to the Future in Antarctica, journalist Fen Montaigne tells the story of the Adelie Penguin and Dr. Fraser's work.  Mr. Montaigne chronicles the five months he spent at the Palmer Station, a U.S. research facility on the Antarctic Peninsula.  He details the effect global warming is having on the Adelie penguin. The classic tuxedoed penguin depends on sea ice to survive.  But the rapid melting of ice is resulting in a shocking decline in the number of Adelie penguins.  They have already disappeared completely from some Antarctic islands, and are on the way out on several more.   

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