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Author Question: In an investigation of the effects of caffeine on concentration, half the participants were given ... (Read 27 times) |
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
Fungal nail infections account for up to 30% of all skin infections. They affect 5% of the general population—mostly people over the age of 70.
Blastomycosis is often misdiagnosed, resulting in tragic outcomes. It is caused by a fungus living in moist soil, in wooded areas of the United States and Canada. If inhaled, the fungus can cause mild breathing problems that may worsen and cause serious illness and even death.
Every 10 seconds, a person in the United States goes to the emergency room complaining of head pain. About 1.2 million visits are for acute migraine attacks.