j

ecological dictionary

J

Japanese encephalitis

A viral disease found in South East Asia, and an example of a zoonosis – a disease which can be passed from animals to humans. The virus, of the family Flaviviridae, naturally occurs in birds. When it infects humans, it often has no ill effects, but sometimes can cause a very serious illness. The disease can be prevented and controlled by vaccination. (See also Vaccine and Zoonosis.)

Jade

A type of stone consisting of a mixture of silicon compounds. Usually green in colour, it can be very delicately sculpted into ornaments and jewellery, and can be very valuable.

Jaguar

Orange-brown and black-spotted ‘big cat’ of the Panthera family, which includes leopards, lions and tigers. Found in South and Central America, e.g. the Brazilian rain forests. Used to be found all over South America, but is now extirpated (wiped out) in many regions, and continues to be threatened as man destroys its natural habitat.

Jargon

Words, like slang, that you wouldn’t necessarily find in a dictionary but are frequently used and understood by people with the same interests. Sometimes they are technical terms used in science or technology, but they can also, for example, be words used by people who follow the same sport. Some words start out as jargon and get used so often that they enter into the language and get included in dictionaries. Good examples of these are a lot of the words used on the internet, such as surfing, hacking, and hyperspace.

Jaundice

Derived from the French word ‘jaune’ meaning yellow. Bilirubin is a naturally occurring yellow-coloured substance in the human body, created when old red blood cells are broken down. The liver removes this substance from the body so that it can be excreted. Sometimes, when the liver doesn’t function well due to a disease, there is a build-up of bilirubin in the body, which causes the eyes and skin to look yellow, which is referred to as jaundice.

Jellyfish

An invertebrate (lacking a backbone) sea creature with a body like an umbrella and dangling tentacles. Actually, not a fish at all, but a very ancient member of the Scyphozoa family, which have a jelly-like appearance. Often very beautiful and highly coloured.

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