Friday, May 3, 2013

The Honey Trap

Most of us have been prescribed antibiotics at some point in our lives. The simple reality of communal species, such as humans, is that bacteria will thrive on our need for social interaction, and thus antibiotics are a common occurrence in modern life. The growing problem of antibiotic resistant bacteria has gained a lot of attention, and rightly so, since widespread use of antibiotics has given rise to deadly strains like MRSA. Scientists across the globe are focusing on the interactions between bacteria and antibiotics to figure out how drugs are causing bacterial genomes to evolve.
But how does antibiotic use affect the people taking them? A study out of Japan made an interesting connection between antibiotic use and human behavior. Minocycline, a tetracycline, was shown to alter male behavior by reducing their risk to fall into the “honey trap” The “honey trap” is when males tend to trust a physically attractive female without evaluating her trustworthiness. Males who were not taking minocycline were found to be increasingly trusting of women as attractiveness of the women increased.  Males on minocycline seemed to be immune to the females’ attractiveness; they did not become more trusting of more attractive women.
Since minocycline inhibits microglial activities, the role of these cells in behavior has been given further weight, but the reason for the behavioral effects of minocycline are not yet clear. The drug may be interacting with glutamate and dopamine neurotransmission, for example, or the suppression of microglial cells may reduce stress response. It may have effects on the amygdala, which is activated during judgments of trustworthiness in human faces and also appears to be one of the most affect regions during minocycline use.
It’s amazing how commonly prescribed drugs can have side effects that we are only now discovering.  You can’t help but wonder how many decisions or actions or any type of behavior has been affected by antibiotics or some other commonly used drug, without the knowledge of the user!

Posted by Joseph Starrett(3)

All images used under creative commons license:

Antibiotics: Flickr user michaelll (
Honey: Wikimedia (Commons

Thursday, May 2, 2013

Killer Whales are Causing a Trophic Cascade

Killer whales are causing a tropic cascade in the Northern Pacific ocean. A tropic cascade is when a top carnivore decreases the abundance of a lower carnivore, which leads to an increase in herbivores and then a decrease in primary producers.  

Over the past two decades, Alaskan Sea Otter populations have been steadily declining.  This decline is caused by killer whales.  Normally killer whales feed on fish, seals, sea lions, and walruses.  In the past two decades, sea otters have been added to the list of killer whale prey.

Sea otters live among the kelp forests in the North Pacific. They are considered a keystone species in kelp forests. They prey on sea urchins.  Sea urchins are herbivores and eat kelp, but the presence of sea otters control the sea urchin populations, which allows the kelp forests to grow. Now since sea otters are declining, it is allowing an overgrowth of sea urchins, which is causing the destruction of kelp forests.  The destruction of the kelp forests is also affecting bald eagles, as they feed on kelp forest fish.

Scientists are unsure what is causing killer whales to prey on sea otters. There are many different theories about the cause. Some scientists have speculated that killer whales used to feed on whales, but stopped because of overexploitation cause be commercial whalers.  With whale populations low, killer whales turned to smaller mammals such as seals and sea lions. However, seal and sea lion populations have decreased. They believe that this decrease has led to sea otters becoming prey to killer whales. Other scientists believe that killer whales would eat the harpooned whales left by commercial whalers, but did not actively seek out live whales. When commercial whaling stopped, they believe that killer whales turned to smaller mammals as food, which in turn started the tropic cascade.

Sarah Tebo (3)

Pepper Spray - Like Seasoning For Your Face!

                Pepper spray is a common tool used for defense by millions of people in this country, but how does it work? Massachusetts' heavy regulation on the item, requiring a license, and the university campuses outright ban (for innocent people only) would lead one to believe this a is a dangerous mysterious substance, but that is far from the case. Most pepper spray on the market is merely a highly concentrated mixture of capsaicin, or the chemical in peppers that makes them taste hot, though there are some other variants on the market which use synthetic active ingredients.
                So how do these mysterious substances work on the human body as a deterrent? Most people I know say getting pepper sprayed was one of the worst experiences of their lives, though none of them bear any lasting effects. In fact all of these people were exposed to the agent as a regular part of law enforcement or military training. Capsaicin based defensive sprays work by immediately agitating  exposed skin and membrane through activation of the TRPV1 channel, intended for thermoregulation and temperature sensing. Plants likely evolved capsaicin to take advantage of this channel as a defense mechanism… and it clearly does that quite well.

                Once these channels are activated the body responds as it would if there were an actual burn to the affected area through swelling and mucous production. This results in a perpetrators eyes swelling shut, as well as difficulty breathing, all in addition to a good amount of pain and discomfort. The effects usually begin to subside within 5 minutes to an hour. Pepper spray is used very frequently both in real life situations and training with no lasting effects. There are, however, a handful of cases where a death has had pepper spray listed as a contributing factor, this is often in the case of someone already under respiratory distress, or with a pre-existing heart condition that is not able to withstand the additional stress.  Generally speaking, however, it is a safe substance with no known lasting effects after a single exposure.
                                                                (language warning)

                So next time you are at a Umass party that gets broken up by the police, and you find yourself getting sprayed with pepper spray, just remember no actual damage has been done to your body, and make sure you ask them to pass the nachos, as you've got some prime seasoning right there!

Michael Ball (1)