ScienceIQ.com

What Are The Dangers Of Lightning?

Lightning is the underrated killer. In the United States, there are an estimated 25 million cloud-to-ground lightning flashes each year. While lightning can be fascinating to watch, it is also extremely dangerous. During the past 30 years, lightning killed an average of 73 people per year in the United States based on documented cases. This is more ...

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DangersOfLightning
Biology

Brain Waves

Your brainwaves normally vary from a low vibrational state of about one Hz ('Hertz,' or vibrations per second) to a high of about 30 Hz. The highest-frequency vibrations, ranging from about 13 to 30 ... Continue reading

BrainWaves
Chemistry

Hydrogen Reaction Experiment Reaps a Surprise

Scientists got a surprise recently when a team of physical chemists at Stanford University studied a common hydrogen reaction. Scientists got a surprise recently when a team of physical chemists at ... Continue reading

HydrogenReactionExperiment
Medicine

What is Headache?

When a person has a headache, several areas of the head can hurt, including a network of nerves that extends over the scalp and certain nerves in the face, mouth, and throat. The muscles of the head ... Continue reading

WhatisHeadache
Biology

Did You Smell Something?

There's not a moment of our lives when smells -- or, more precisely, odor molecules -- aren't impacting our brain. It's been estimated that it takes at least 40 molecules of a given odor for us to be ... Continue reading

Smell

Yes! We Have New Bananas

YesWeHaveNewBananasDid you know that a plant disease determined what banana variety is in your market? Bananas, which originated in Africa and are now grown in every tropical region, are perhaps the most popular fruit in the world. It is the most popular fruit in the U.S. even though we import nearly all of them. In addition to dessert bananas, the banana family also includes plantains, cooking bananas and abaca, a fiber plant called Manilla hemp. For many years the most popular banana sold in the United States was the variety 'Gros Michel', a preferred banana for shipping. However, 'Gros Michel' is very susceptible to Panama disease, a vascular wilt caused by a soil fungus, Fusarium oxysporum f. sp. cubense. It kills the banana plants by infecting the xylem (the water-conducting tissue) and destroying the plant's ability to distribute water and minerals to its tissues.

For a long time, banana growers moved their plantations to new fields to escape the disease, but as these new plantations became infected the growers eventually ran out of new ground. As a result many 'Gros Michel' plantings were converted to the more resistant 'Cavendish' varieties, even though in time these bananas also became diseased. So this disease has determined what banana you can buy.

Panama disease, also known as Fusarium wilt, is believed to have originated in Asia but gets it name from the damage it caused to banana plantations in Panama, as well as in other Central American countries, in the early 1900s. Bananas must be replanted after fruit production. They are not perennial trees. Since bananas are propagated vegetatively by suckers from the base of the plant, the fungus rapidly spread throughout banana growing areas. Once in the soil, the fungus can survive for many years and is spread further by machinery, contaminated soil and water, and by other physical means.