Skip to main content

Posts

Showing posts from October, 2013

The curious case of the antechinus

Semelparity is one of those words you choose when you’re playing Balderdash. When you see it you immediately know that no one at the table knows the definition or even has a clue about its place in the English language. That is unless you have an absurd number of animal behaviorist friends.  Semelparous organisms are those that have one chance to mate before they die. There are more of these types of organisms that I would have expected (salmon, some spiders, grain plants) but I never would have guessed that a mammal would be semelparous. If you know anything about evolution then semelparity sounds completely ridiculous! Reproductive success is the key to species’ survival. So then why would evolution favor an animal which dies after a single mating event?  This is the question many behaviorists have been asking about animals like the brown antechinus (an-tee-kine-us). The antechinus is a marsupial mammal found in Australia whose male counterparts have only one opportunit

Wrinkle, Wrinkle

“I just love the feeling of paralyzed muscles in the morning.” This is what I imagine people are saying to themselves as they willingly, nay, enthusiastically receive Botox injections. The rumors you’ve heard are true; Botox does in fact contain a deadly neurotoxin that is more potent than any snake or spider venom you’ll come across. The same neurotoxin that causes botulism and consequently kills about 145 people a year in the states. The Botox injections that are used for various cosmetic and medical procedures are a derivative of a botulinum toxin (hence the creative name Bo-Tox). The toxin is produced by Clostridium botulinum, a bacterium commonly found in food products like poorly packaged meat and canned foods. When I say it’s potent what I really mean is POTENT—think LD50 around 1ng/kg in rats. That means that a 150 pound person would only need to receive about .000000068 grams of the stuff in order to give him a 50% chance of dying. This toxin is so potent that the DN

One more reason to eat your vegetables

Scarfing down broccoli in elephantine portions doesn’t sound like the best way to treat radiation exposure. However, recent research has isolated a compound found in broccoli and other so called cruciferous vegetables which may do just that. The molecule looks like this and is called 3,3’-diindolylmethane, or DIM for short. In a paper published in Proceedings of the National Academy of Sciences scientists treated rats that had undergone total body irradiation with doses of DIM and observed increased survival rates compared to rats that had not received the treatment. While administering DIM before total body irradiation required a smaller dose to elicit the same effect, administering DIM after total body irradiation also resulted in better survival rates for the rats. You can imagine that this treatment could be useful in many situations, like to help chemotherapy patients recover more quickly or to treat people who have been accidentally exposed to radiation. How does

Sensing the senseless: Dizziness in the brain

Getting dizzy used to be fun. Tire swings and merry-go-rounds offered endless entertainment for my young friends and me. We would spin and spin and spin until we could no longer walk and we just collapsed into a pile of giggling goons. Not so these days. It is rarer and rarer that I find myself getting dizzy on purpose and more and more common for me to get dizzy without doing any spinning at all. Dizziness is one of those weird phenomena that everyone experiences, whether you’re a hyper kid or plagued with bouts of vertigo. But how do we get dizzy anyways? Imagine yourself in your car with a full mug of piping hot coffee in the cup holder next to you. You know that you have to drive really carefully to keep all the coffee in the cup, because the motion of the coffee is directly affected by changes in your car’s acceleration. If you brake too hard or take a curve too fast the coffee sloshes out of the cup. Similar movements are happening in your vestibular orga