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Archive for the ‘science’ Category

Simple Test

No one wants to eat pesticides, but testing food and water takes time and money. Scientists in Hamilton, Ontario have developed a test for pesticides that is as simple as dipping a small strip of paper in a sample of food or water and waiting for a few minutes. Most pesticides affect the nervous system by interfering with the enzyme acetylcholinesterase, so the strips have this enzyme on one end and IPA on the other. IPA is a compound that turns blue when acetylcholinesterase breaks it down.

Here’s how it works: the enzyme end is dipped into a sample, and the IPA end is dipped into water. Capillary action causes the moisture from the two ends to flow into each other, and the resulting colour tells you if you have pesticides or not. If it turns blue, there are no pesticides and the acetylcholinesterase was able to break down the IPA. If there are pesticides present they will not allow as much of the acetylcholinesterase to work, so the shade of blue will be lighter. It will vary depending on the amount of pesticides present.

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Article condensed from:  The New York Times, Tuesday, December 29, 2009

“A Simple Paper Test May Detect Pesticides”

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Here’s a simple activity that illustrates this process: First find a coffee filter, some markers, and a cup of water. Next, cut the coffee filter into strips about an inch wide. Then, choose two different coloured markers and draw a tiny circle on each end of the coffee filter strip. Colour them in. Finally, dip each end of the strip into water for 2 seconds and lay it flat. Watch and wait. What happens to the colours as the water moves in the strip? This movement of water is called capillary action, the key mechanism in these pesticide-testing strips.

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Plants That Conserve Water

Scientists are hoping to engineer plants so they require less water to grow. Plants need carbon dioxide to survive and flourish, and they need water to take in the carbon dioxide. They have openings on their leaves, called stoma, which take in carbon dioxide and release water. If there are lower levels of carbon dioxide in the air, their stoma will need to be open wider. In the case of the elevated carbon dioxide levels today – about 40% higher than in the preindustrial era – it may be possible for plants to decrease the opening of their stoma and still gain enough carbon dioxide. The smaller opening would also mean that less water was lost, which means those taking care of the plants could give them less water.

Some plants are not sensitive enough to carbon dioxide levels, so scientists are hoping to genetically alter the plants with more carbon dioxide sensors. Being able to sense the increased carbon dioxide levels will enable the plants to conserve water better. This will be useful in areas where water is more scarce.

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Article condensed from: The New York Times, Tuesday, December 29, 2009

“Findings on How Plants Breathe May Save Water”

Picture from Flickr:

Stoma

Originally uploaded by Ian Geldard

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Transparent Fish

In Japan, researchers have bred certain goldfish to be transparent. If you look closely enough, you can see the brains, heart, and other organs inside one of these fish without dissecting it. The researchers selected goldfish with paler skin and scales and bred them together to create this new line of goldfish they can see through. The albino goldfish, when bred together over generations, became more and more translucent, allowing scientists to see their organs. Breeding them together, rather than genetically altering their DNA, was the method of choice. They are natural organisms, although their parents were selected specifically for breeding together. These goldfish should live for 20 years, if all goes well, and weigh 2 kilograms or more. It will be interesting to see how the organs grow and develop over time – many people will be watching the insides of these fish.

Snow White

Originally uploaded by Elinesca on Flickr

This post was summarized from an article in The Globe and Mail, Wednesday, December 30, 2009: Japanese Researchers Develop World’s First See-Through Goldfish

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