Tuesday, November 27, 2012

Rise of the Zombie Ants

Image source: Flickr. Xenomurphy.

America has gone crazy for zombies. In the past few years there has been a huge rise in media portraying zombies, whether they take the form of video games, TV shows, books, or movies. The only thing that can console people terrified of zombies is the fact that zombies don’t exist. At least the public thought zombies did not actually exist until a discovery was made in 2011.

Zombie Ground Zero
Image source: Flickr. Armed Forces Pest Management Board.
Carpenter ants (technically Camponotus leonardi) in Thailand are being “zombified” by a unique fungus in the genus Ophiocordyceps. The “zombification”process starts when an ant comes into contact with one of the fungus’ microscopic spores. In the beginning, right after exposure, the ant behaves normally as if nothing happened. During this time, the fungus grows within the ant and slowly degrades muscles and other internal organs. Eventually the fungus takes over the brain, gaining complete control of the ant’s body and movement.

Spreading the Undead Love
Image source: National Geographic. David P. Hughes.
Once the fungus is in charge the zombie ant moves to a moist area of the forest and bites down on the vein of a leaf. At this point, the fungus moves into the ant’s mouth and breaks apart muscles so that the ant can never let go of the leaf. After a few days the fungus bursts out of the ant in the form of a fruiting body that releases spores. These spores are then (unfortunately) picked up by other ants, causing the cycle of life and “undeath” to repeat itself.


Finding a Cure
This fungus might be a little disturbing to think about, but so far there have been no instances of it affecting any other organisms aside from carpenter ants. According to entomologist David Hughes, there is also a glimmer of hope and salvation for infected ants. Even if an ant picks up a Ophiocordyceps spore, it can still lead a normal life so long as it encounters another, mystery fungus. This fungus is unique in that it can efficiently kill off Ophiocordyceps without harming the host ant, stopping the "zombification" before it’s too late. Thankfully, for now, the threat of a zombie apocalypse is only real in the movies.

Friday, November 23, 2012

A Mythbusters Thanksgiving


Image Source: Flickr. Joits.
Even if there were dozens of casseroles, potato concoctions, and pies, Thanksgiving dinner just wouldn’t be complete without turkey. It’s a prime American tradition to meet family, watch football, eat massive amounts of turkey (among other things), and then fall into a sort of food coma. But why does the food coma occur in the first place?

Image Source: HowStuffWorks.
Turkeys and Tryptophan
The most common reasoning for the Thanksgiving food coma is that it is the result of massive tryptophan intake. Tryptophan is an amino acid (or building block for proteins) commonly found in turkey that is used in the production of serotonin, a hormone that triggers sleepiness and relaxation in people. Since people eat a lot of turkey on Thanksgiving, it’s assumed that they also process a lot of tryptophan and serotonin. The combination of these two compounds allegedly results in the infamous food coma.




Debunking Tryptophan
Image Source: Flickr. Hectichousehold.
Other studies have debunked the tryptophan-sleep hypothesis based on two different reasons.

1) Tryptophan is abundant not only in turkey, but all poultry.
Following this factoid, it would be logical to assume that a person should fall into a similar food coma after eating a lot of chicken. However, that chicken-induced sleep event never occurs.

2) Tryptophan only triggers serotonin production in an empty stomach
When tryptophan is present in a stomach full of other foods and amino acids, it essentially has to compete with those other molecules to induce some sort of effect on the body. As a result, the serotonin production from tryptophan in someone with a full stomach is much more reduced in comparison to that of someone with an empty stomach. Since Thanksgiving is one of the few days it’s socially acceptable (and encouraged) to eat a lot, there is no way someone would have an empty stomach so tryptophan could function properly.

A Smorgasbord of Possibilities
While there is proof that tryptophan may not be the sleep-inducing agent, some researchers believe that a mix of carbohydrates (from essentially everything on the Thanksgiving menu) and tryptophan can result in sleepiness. Other scientists think that the process of digesting all of the food from the day takes a greater toll on the body, resulting in the food coma. There are a lot of ideas about the situation, but no concrete explanation for why it happens just yet.

Tuesday, November 20, 2012

An Aid to HIV


Image Source: Flickr. Kristian Hay



In recent years there has been a strong push toward safe sex in order to prevent the spread of STDs, or sexually transmitted diseases. However, when Americans from ages 18 to 64 were asked about STDs most could list a few major diseases but 12% could not list even one. Only 23% mentioned chlamydia, the most prevalent STD in the nation. It turns out that Americans may realize that they should use condoms and other tools for safe sex, but they don’t exactly know the reasons why.



Image Source: Kaiser Family Foundation.
Sexually Transmitted What Now?
These misconceptions even transfer to HIV, one of the most publicized STDs in the world. 34% of the same set of Americans thought that HIV could be transmitted via sharing a drinking glass, touching a toilet seat, or being in a pool with someone who is HIV+. Most don’t even realize there is a difference between HIV and AIDS.





The Facts
Image Source: Reuters.
So what are HIV and AIDS? HIV stands for Human Immunodeficiency Virus, a condition that be spread only through sexual contact or exposure to infected blood. This virus infects and kills the immune system’s CD4+ T cells that normally deal with infections, making it so that a body has trouble responding to viruses or bacteria. Once HIV kills enough T cells, it turns into AIDS, the Acquired Immune Deficiency Syndrome. At this stage, so many T cells have been destroyed that it is impossible for the body to fight any other infections, making even the common cold a deadly illness.

Looking to the Future
HIV works slowly, so it can take years for it to destroy enough of the immune system to be problematic or even noticeable. There are a lot of symptoms that can indicate HIV infection, but they can be easily mistaken for other diseases. The only real way for people to know if they have the disease is to get tested for it. As of now there is no cure for HIV, only a concoction of medicines that can slow down its progression to AIDS from years to decades. There is ongoing global research for a vaccine, though, and one group of South African scientists recently discovered a potential wayto target the virus itself. For now, though, all people can do is to be safe (and knowledgeable) when having sex.