Better Insect Repellent Discovered

May 25, 2011

Unlocking Word Meanings
Read the following words/expressions found in today’s article.

1. repellent (n.) – a substance that keeps or drives away something
Example: The strong smell of insect repellents drives away mosquitoes.
2. compound (n.) – in chemistry, it is a substance made from two or more elements
Example: H2O is a compound composed of hydrogen and oxygen.

3. mammal (n.) – an animal that has the following characteristics: (1) body covered with some hair; (2) its young fed with milk from its breast (or mammary glands); (3) gives birth to a live young
Example: Most mammals do not lay eggs.
4. odor (n.) – the quality of a substance that can be identified by the sense of smell
Example: Acids release unpleasant odor.

5. confuse (v.) – to cause the inability to think clearly
Example:  I got confused in the exam because the instructions were unclear.  

Read the text below.

Scientists from Vanderbilt University discovered a better formula which can replace DEET, a common ingredient used in insect repellents. The newly discovered compound is called VUAA1 and it works against all insects.

Scientists found out its effectiveness after studying the unique smelling process of mosquitoes. At first, scientists thought mosquitoes use their sense of smell the same way mammals do. Mammals have odor receptors (ORs) which are activated when particles of substances hit their smelling organs. Once the receptors are activated, these receptors tell the brain what kind of substance it is.

But, the research shows that mosquitoes have a different way of smelling. Their ORs do not communicate directly to the brain, but depend instead on another receptor called Orco which acts as a switch. Once mosquitoes smell a substance, Orco identifies which OR is activated and tells the brain what substance is smelled.

Scientists discovered that VUAA1 directly affects Orco unlike DEET which affects individual ORs. When Orco is stimulated, all ORs are activated confusing mosquitoes with different odors being smelled at the same time. In this way, mosquitoes cannot smell anything, not even blood.

The discovery of mosquitoes’ unique smelling process makes it possible to produce more effective repellents which can prevent diseases such as malaria.

Currently, scientists at Vanderbilt are studying the VUAA1 compound further to make sure that it is safe for consumers and the environment.

Viewpoint Discussion
Enjoy a discussion with your tutor. 

Discussion A
·         Why do you think companies continue to make products that are harmful to the environment?
·         Why do you think is it important to consider the effect of a certain product to the environment?

Discussion B

·         What do you think are the advantages and disadvantages of using insect repellants?
·         In what situations do you think should we make use of insect repellants?

May 25, 2011