Category Archives: Biological Sciences

Why don’t Zebras get ulcers?

  Imagine living on the African plains, spending most of your day finding food to fill your daily calorie load. In addition, there are predators in the shadows, not far away; you have to always watch your back.  Sounds like stressful life, doesn’t it?

  In a way, we all know being stressed is bad for the health. Nevertheless, stress response is an evolutionary trait with benefits—exhibited by numerous members of the animal kingdom. Becoming stressed generates a series of physiological changes that prepare animals for the Fight-or-Flight behaviour. The level of stress hormone, corticosteroids rises and activates the body: the heart start racing, breathing is faster, and the muscles become tensed. So, for the 30 seconds that you find a lion chasing after you, stress is very helpful and essential to your survival. Continue reading

Tree Rings Give Scientists Insight to Earthquake History

It’s something we’ve all probably heard through the grapevine – the ‘looming’ earthquake that is going to hit the Vancouver region. After the recent devastation on Japan, one may be led to wonder, how are the effects seen down the road? Will the anguish still be prevalent hundreds, or even thousands of years from now?

In a recent conversation with Tom Balakshin (a friend and avid geologist) about the earthquake history in the Pacific Northwest, he enlightened me on how scientists track the history of seismic activity – specifically noting an earthquake that occurred in Northwest Washington approximately 1000 years ago. Though physical traits such as an abrupt uplift in shorelines, and evidence of a deposition from a tsunami, one of the most fascinating discoveries looks past the land formations, and to the vegetation of the surrounding land.

Prehistoric rock avalanches (believed to be the product of forceful seismic activity) in the Olympic Mountains between 1000 and 1300 years ago caused surrounding trees and plants to be completely submerged in water – trapping them in by rock dams. Scientists were able to determine the trees that drowned during the avalanche by observing tree rings. Trees that were underwater showed patterns uncharacteristic of those in normal conditions, such as diminished wood quality and varying ring spacing due to the death of outer layers. Analysis of the dead wood allowed scientists to determine that the avalanche predated the last ring about 100 years, as well as also indicating which season the trees died in.

Who would’ve thought that the rings of a tree could not only tell age, but also the environmental conditions that were present at that time? Even though the memories of those victimized through these devastations never fade, this just goes to show the Earth itself has its own way of keeping track of these natural catastrophes.

Check out this brief video on how scientists actually use the rings to reveal the tree’s history!

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Musical Microbes

A study recently done which was published in the journal General Dentistry yielded surprising results, which make me wonder how many nasty things I was exposing myself to in band class once upon a time… A shocking 442 different types of bacteria were found to be growing on 13 different instruments which were swabbed in 117 different places.

It wasn’t only bacteria which they found though. Also present on these instruments were 58 types of mold and 19 types of yeast. What’s worse (besides the fact that woodwind instruments had the highest number of microbes) is that the the species that were found were highly resistant to most of the antibiotics which are generally used.

Among the bacteria, many species of Staphylococcus were found, which are known to cause a variety of different things ranging from minor skin infections such as pimples to more serious conditions such as pneumonia and toxic shock syndrome. This youtube video shows the different places in which Staphylococcus can also be found, and why it’s important to be careful.

Not surprisingly, it was shown that mouthpieces tended to have more contamination than the other parts of the instruments studied, which included the cases. The instrument which was found to have the highest number of contaminants was the clarinet, and brass instruments generally had lower numbers of microbes present.

An easy way to prevent these instruments from getting so filthy is to sterilize them on a regular basis using ethylene oxide. However, it is worth noting that it should not be overused. Ethylene oxide has narcotic effects, and chronic exposure may lead to the induction of mutagenic effects, and it has been proven to be a carcinogen by the International Agency for Research on Cancer.

As with any situation involving microbes, the best solution is to keep to yourself, wash your hands, and keep clean!

Carnivorous Furniture Powered by Bacteria

Robert Krulwich, in his blog ‘Krulwich Wonders’, recently  wrote about the fascinating and morbid creations of designers James Auger and Jimmy Loizeau. These creations are typical furniture such as a clock, lamp, and table, but are built to have a carnivorous streak.

James Auger and Dr. Chris Melhuish speak about their creations:

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During the development of a digital wall clock powered by flies, Auger and Loizeau drew inspiration from carnivorous plants that trapped insects and consumed them for nutrients. A trap mechanism, which consisted of a slowly rolling sticky conveyor belt, deposited any unfortunate flies into a microbial fuel cell sitting below the belt. The display of the clock was powered entirely by the energy obtained from the digestion of the flies. However, the conveyor belt motor was powered by battery or through an outlet, since the trap did not catch enough flies to power the motor.

A microbial fuel cell is a chamber that contains bacteria, which consume organic material. During consumption, the bacteria release electrons that the fuel cell channels to generate electricity and power whatever is connected to the cell. Microbial fuel cells have also been used to generate power from algae.

A dirt-based microbial fuel cell (MFC) - By: Engineering for Change via Flickr

Dr. Chris Melhuish and his team at the Bristol Robotic Laboratory have utilized microbial fuel cells to power robots called ‘EcoBots’. These robots are outfitted with microbial fuel cells that created a system, similar to digestion, which effectively extracted and used energy from the environment. For example, dead flies fed to the robot were digested by bacteria in the microbial fuel cells, the ‘gut’ of the robot, to provide energy for motion. Presently, the fuel cells are only capable of powering short spurts of movement. The research team aims to develop microbial fuel cells that are able to power continuous movement.

With the prices of oil rising, this technology is definitely important in the development of an alternative and renewable fuel source. Personally, I would not mind a fly powered clock, but I would steer clear of a mouse consuming coffee table.