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.
Article
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?
