Ask Mr Brain...all will be explained

PUBLISHED : Wednesday, 16 May, 2001, 12:00am
UPDATED : Wednesday, 16 May, 2001, 12:00am

What is athlete's foot?

Athlete's foot is a very common skin problem that usually affects teenage and young adult men, but almost everyone will get it once in their lifetime.

It is a fungal infection that grows and multiplies on the skin. Many people have the fungus on the skin but do not develop infections.

The fungus multiples in warm, moist conditions - sweaty feet in socks and shoes provide the ideal environment for the fungus to grow.

Most sufferers will have peeling, cracked and blistered skin between the toes and along the sides of the feet. Usually the affected areas are itchy, and if left untreated, may become painful.

The condition can usually be treated with powders, sprays and creams, and in more severe cases, medication may be needed. The best way to prevent athlete's foot is to wash the feet frequently and avoid wet footwear.

How do gun silencers work?

The proper name of silencers is sound moderators or suppressors. They are widely used by hunters to reduce noise from the discharge of firearms, particularly sporting rifles and air weapons.

A sound moderator is in fact a series of baffles coupled to an expansion chamber, contained within a tubular attachment which screws on to the end of the firearm's barrel.

The noise of the discharge of firearms is made up of two components. The first comes from the rapid expansion of propellant gases as they leave the muzzle. The second is the supersonic crack of the bullet. The sound level of a supersonic bullet cannot be reduced, but a sound moderator can significantly reduce the noise signature because it controls the rate of expansion of the propelling gases.

A sound moderator must be used with ammunition whose projectiles travel at less than the speed of sound in order to be really effective. In such cases, the noise of the discharge is significantly reduced and may not even be recognisable as a gun.

What is a surrogate mother?

A surrogate mother is a woman who bears a child for a couple unable to produce children. Normally, the surrogate mother gives up all parental rights, but this has been subject to legal challenge.

Surrogate mothers were not unknown in previous times. But they came to international attention in the mid-1970s. At that time there was a decline in children available for adoption. Also, the development of modern techniques in human embryology made surrogate motherhood possible. Childless couples who had to undergo uncertain and lengthy adoption procedures preferred to obtain the services of a surrogate mother.