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Past Episodes: February 2011 Archives

Saturday February 26, 2011

* The Benefit of a Bilingual Brain * Hibernating Bears * World's Oldest Water * Strange New Worlds * Lambs and Longevity *
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The Benefit of a Bilingual Brain


Bilingualstopsign.jpg
It is well known that stimulating activities, including crossword puzzles or learning to play the piano, are beneficial to the brain's cognitive ability.  One of the areas of cognition that benefits is executive function, which is key to thought processes like memory.  But a new study by Dr. Ellen Bialystok, Distinguished Research Professor of Psychology at York University in Toronto, has determined that being bilingual also boosts the brain's performance and can even delay the onset of Alzheimer's disease.  The study involved over 400 patients - divided into bilingual and monolingual groups  - and all at equal stages of probable Alzheimer's disease.  The study showed that bilingual patients had been diagnosed 4.3 years later on average, and had reported the onset of symptoms over 5 years later than the monolingual patients.  Being able to speak a second language will not prevent Alzheimer's, but it can help patients cope with the disease for longer.

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Hibernating Bears

black_bear.jpg Courtesy Øivind Tøien
One of the main reasons animals hibernate is to shut down and conserve energy in periods when there is no food available, such as winter.  During the 5 to 7 months that black bears hibernate, their body temperature decreases and metabolism slows.  But new research by Dr. Craig Heller, a Professor of Biology and Human Biology at Stanford University in California, has found a few surprises.  One is that bears regulate their body temperature over a cycle of a few days.  It drops to as low as 30 degrees then rises to 35 or 36 degrees, just below normal.  But the big surprise was that the bear's metabolism dropped to 25% of normal, much lower than previously thought.  This study in Alaska was the first to monitor black bear's body temperature, heart rate, muscle activity and metabolism throughout their entire hibernation period.  It is hoped that understanding bear hibernation could be applied to many human ailments, such as inducing similar hypothermic conditions immediately following a stroke to reduce the loss of brain function.  

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World's Oldest Water

oldest_water.jpg Finding the Earth's oldest water in a South African gold mine, courtesy Dr. Barbara Sherwood Lollar
Water found three kilometres down in the gold mines of South Africa's Witwatersrand Basin are believed to be the oldest on Earth.  The water is found in fractures in the two-to-three billion-year-old rock and has been isolated from the surface for a long period of time, possibly tens of millions of years.  New research by Dr. Barbara Sherwood Lollar, from the Department of Geology at the University of Toronto, suggests the key to the water's age is the presence of neon.  The neon's specific isotope signature tells them that it was trapped within this rock at least two billion years ago.   Another element of this study was that one of the fracture systems in the rock contained the deepest known microbial ecosystems on Earth.  These are organisms that exist without sunlight and thrive on the chemical energy that originates from rock.  Because the rock that comprises the Canadian Shield is the same age, it is reasonable to believe that similar findings could be made here in Canada.  

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Strange New Worlds


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Over the last 15 years, the hunt for planets around other stars has bagged a lot of big game.  Using new technology and innovative methods, astronomers have detected hundreds of planets, and have unconfirmed observations of more than a thousand others.  Dr. Ray Jayawardhana, Canada Research Chair in Observational Astrophysics at the University of Toronto, has been at the forefront of what has become the hottest field in astronomy.  His group was the first to directly image an extra-solar planet.  In his new book, Strange New Worlds: The Search for Alien Planets and Life Beyond our Solar System, he explores the past, present and future of our search for alien planets, and our progress to the ultimate goal of finding Earth-like planets and, perhaps, life elsewhere in our galaxy.   

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Lambs or Longevity


soay_sheep.jpgSoay Sheep, courtesy Arpat Ozgul/University of Edinburgh
Soay sheep live on remote islands off the coast of Scotland.  They're untroubled by predators, but lack of food, harsh weather and disease take a heavy toll.  Dr. Andrea Graham, an immunologist and evolutionary biologist at Princeton University and the University of Edinburgh, and her colleagues have been investigating the relationship between immunity, fertility and longevity in these animals.  It appears that the sheep that live the longest have the strongest immune systems, but pay a price for that with reduced fertility.  This is a classic evolutionary trade-off that might also cast light on questions of human immunity and fertility.

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

Saturday February 19, 2011

* Getting a Toe-hold on Early Prosthetics * Artificial Intelligence wins Gold * Leaf-cutters, When they Can't Cut It * Spit Out Your Genes *
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Getting a Toe-hold on Early Prosthetics


mummy_toe.jpgAn ancient Egyptian false toe. Courtesy, Jacky Finch, with permission from the Egyptian Museum, Cairo, Egypt
Two false toes, dating back to ancient Egypt, are believed to be the oldest known prosthetic devices.  Both are big toes from the right foot, and both were found near present-day Luxor.  One toe, found in the 19th century, is thought to have been made in about 600 BC. It is crafted from one piece of cartonnage - a linen and animal glue version of papier-mache.  The other toe dates back to between 950 and 710 BC.  It was found attached to the foot of a mummy in a tomb just over ten years ago.  This toe is comprised of three pieces, two are wood, the other possibly leather.  It had been suggested that because ancient Egyptians believed the body should be prepared for the afterlife in a complete state, the toes were purely decorative.  But new research by Dr. Jacky Finch at the KHN Centre for Biomedical Egyptology at the University of Manchester, England, proves otherwise.  The toes were recreated to fit amputee volunteers and tested for flex, pressure, gait and comfort.  Both performed remarkably well as functioning prosthetic toes.

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Artificial Intelligence wins Gold

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Canada's highest prize for science and engineering, the Gerhard Herzberg Canada Gold Medal, was awarded this week to Professor Geoffrey Hinton for his pioneering work on Artificial Intelligence and Neural Networks.  Dr. Hinton, a professor at the University of Toronto and fellow of the Canadian Institute for Advanced Research, has worked to develop computers that can respond intelligently to the complexities of the real world, by developing techniques that help computers learn in ways similar to the human brain.  It's an interesting coincidence that Dr. Hinton was recognized for this work in the same week that IBM's Watson computer won on the game show, Jeopardy

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Leaf-cutters, When they Can't Cut It

Leaf-cutter ants use their razor-sharp mandibles for slicing leaves into small disc-like shapes, which are then carried back to underground nests and turned into food.  The ants doing the actual cutting are usually members of the generalized forager caste; one of four size-based behavioural castes of workers.  Such division of labour is well known in social insects like ants.  But new research by Dr. Robert Schofield, a Senior Research Scientist in the Department of Bio-Physics at the University of Oregon, has found that the mandibles of those ants doing the cutting become dull over time.  Even though the blades are made of a zinc-rich material that is wear-resistant, it is not wear-proof.  The study shows that when leaf cutting starts to take about three times longer than normal, those ants are re-assigned.  Similar to humans who experience declining skills due to age, the ants take on more age-appropriate tasks.  In this case, they stop cutting and become carriers. 

Related Links
  • Paper in Behavioral Ecology and Sociobiology
  • News from University of Oregon
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Spit Out Your Genes


DNA_kits.jpg DNA testing kits


This month marks the 10th anniversary of the sequencing of the Human Genome.  The project marked the beginning of a new age of genetic research - and promises of new remedies and cures for genetic diseases. One byproduct of the new world of genomics is already a reality: the direct-to-consumer, home genetic test.  You can now get your DNA analysed from the safety and comfort of your own home.  And while it may not be cheap, it is relatively quick, convenient, and easy.  But the tests come with a fair bit of controversy. So we asked Quirks contributor, and freelance science journalist Alison Motluk, to be our guinea pig, and submit her own DNA for home genetic testing. She sent her spit and cheek swab samples to 2 companies: 23andMe, and DeCode Genetics.

Chris Trevors is a genetic counselor at Sick Kids Hospital in Toronto and secretary of the Canadian Association of Genetic Counselors. He thinks people shouldn't do these tests without thinking very carefully about them. There are a lot of implications and they can go beyond just your own personal health, such as whether to share bad news with siblings who share your genes.

Dr. Joanna Mountain is a geneticist and Senior Director of Research at 23andMe. She says we may know a bit about our family's health history, but genetics can fill in the gaps and provide valuable information - especially for adopted persons. And she feels home testing kits can make it easy and accessible.

Dr. Timothy Caulfield is a lawyer and bioethicist at the University of Alberta in Edmonton. He says  the average person doesn't know how to interpret the test results, especially when they involve degrees of risk for developing a particular disease. Dr. Mountain disagrees. He also fears that people will over-react to an increased genetic risk, by either seeking unproven therapies or becoming fatalistic.

In Canada, Direct-to-Consumer genetic testing is unregulated, as it falls outside the scope of both the Food and Drug Act, as well as the Medical Devices Regulations from Health Canada. In the US, the FDA has recently warned companies that sell laboratory-to-consumer genetic testing that their products cannot be marketed without FDA approval.   

Related Links
  • 23andMe
  • deCODEme
  • Dr. Caulfield's paper in Science: Regulating Direct-to-Consumer Personal Genome Testing
  • CBC news story
  • TEDMED Talk by 23andMe founder Anne Wojcicki on benefits of genetic testing
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Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0

Saturday February 12, 2011

* Playing Footsie with Lucy * Give a Fox a Bone * A Killer Diet * Kissing a Comet * Explaining the Seahorse * Dark Matter Detection? *
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Playing Footsie with Lucy


aa_foot.jpgA. afarensis foot bone and human foot. Courtesy K Cogndon, C WArd and E Harman
Australopithecus afarensis, the 3.2 million-year-old fossil, is best known from the fossil skeleton called Lucy, and represents an important transitional form between our ape-like ancestors and modern humans.  But Lucy, and other A. afarensis fossils, were missing critical bones in their feet that would tell scientists whether this creature had an ape-like or human-like foot.  Now Dr. Carol Ward, a professor of anatomy at the University of Missouri College of Medicine, and her colleagues, have found a critical foot bone that tells the story.  It confirms that Lucy and her species had a modern human-like arched foot, well suited to walking and running, but not so useful for grasping and climbing trees.

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Give a Fox a Bone

fox_skull.jpg The red fox skull from cemetery in Jordan, courtesy Lisa Maher
The earliest cemeteries in the Middle East were thought to have existed in the Natufian period, 15 thousand to 12 thousand years ago.  But Dr. Ted Banning, an anthropologist at the University of Toronto, and his colleague Dr. Lisa Maher, (also from U of Toronto, and the lead author and director of the excavations), have found an older one - the earliest cemetery in the region.  It is located in northern Jordan and dates back over 16 thousand years to a period called the Geometric Kebaran; a period not previously known for the use of cemeteries.  But of eleven human remains found at this site, two were buried along with red fox remains in a ritualistic manner.  A single fox skeleton was distributed between the two human graves.  This discovery suggests foxes may have been regarded in a similar way to that of dogs in later time periods; either as pets or hunting companions. 

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A Killer Diet

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 Killer whale attacking a gray whale calf, Photo: John Durban
Every Spring, gray whales migrate north from the Pacific Ocean, off the coast of southern California, to the Bering Sea.  But their journey is slowed by the awkward trip around Unimak Island, in Alaska.  Dr. Lance Barrett-Lennard, a research scientist at the Vancouver Aquarium, has found that, at this point in the gray whale journey, a population of about 150 transient killer whales lays in wait for them.  For about one month, these killer whales feed exclusively on gray whale calves by, first, separating them from their mothers, then driving them into water at a desirable depth of 20 to 40 metres, where the calves are then attacked, drowned and eaten.  But surprisingly, the killer whales return a day later to continue feeding on the gray whale carcass.  This marks the first time such food storage behavior has been reported in whales. 

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Kissing a Comet


tempel 1.jpg Comet Tempel 1 after Deep Impact, courtesy NASA/JPL-Caltech/UMD


In 2005, NASA's Deep Impact Spacecraft delivered an impactor to the surface of the comet Tempel 1.  The idea was to study the 6-kilometre-wide comet's composition and photograph the crater resulting from the impact.  But dust particles raised by the impact prevented the spacecraft from capturing a clear image of the crater.  That is why the Stardust-Next spacecraft will take another look at Tempel 1 as they come within 200 kilometres of each other next week; the rendezvous will take place appropriately on Valentine's Day.  Dr. Joe Veverka, a Professor of Astronomy at Cornell University and the Principal Investigator on NASA's Stardust-Next Mission, is especially excited by the prospect of - for the very first time - having a second look at a comet, and in particular, the 'fresh' five-year-old crater on Tempel 1.  New images and analysis of dust particles will provide valuable information about the composition of Tempel 1 and comets in general.   

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Explaining the Seahorse

The seahorse seems like a creature more suited to fantasy than reality.  It's an attractive fish, but seems to have made many sacrifices for beauty.  Its belly-first posture makes it a terrible swimmer, and not well suited for pursuing prey or avoiding predators.  Dr. Lara Ferry, a biologist at Arizona State University, and her colleagues, have found one explanation for the seahorse's shape.  Its tilted head gives it a real advantage in closing the distance on the tiny crustaceans it eats.  When its prey are close, the seahorse can snap its head up remarkably quickly, and suck them in through its tube-like mouth..
   

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Dark Matter Detection?

dark matter.pngDark Matter - artist's impression
Dark Matter, thought to represent more than 3/4 of the matter in the universe, has never been seen or felt, since it is invisible and doesn't interact with normal matter.  Its presence has only been inferred from the gravitation pull it seems to exert.  But Dr. Dan Hooper, Associate Scientist at the Fermi Laboratory in Chicago, and an assistant professor of Astronomy and Astrophysics at the University of Chicago, thinks he's now seen another, more direct trace of dark matter: a glow of radiation from the centre of our galaxy that he thinks is the radiation from dark matter particles colliding and annihilating each other.
   

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