Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution.

Pragmatism is a philosophical tradition that began in the United States around 1870. Pragmatism is a rejection of the idea that the function of thought is to describe, represent, or mirror reality. Instead, pragmatists develop their philosophy around the idea that the function of thought is as a instrument or tool for prediction, action, and problem solving. Pragmatists contend that most philosophical topics - such as the nature of knowledge, language, concepts, meaning, belief, and science - are all best viewed in terms of their practical uses and successes rather than in terms of representative accuracy.

The Los Angeles County Tobacco Control Program (TCP) is part of the Division of Chronic Disease Prevention and Health Promotion in the Department of Health Services. It was established as a result of the tobacco tax initiative of 1988, Proposition 99/AB75, in December of 1989. The goal of TCP is to establish policies, health services, public education, and media conditions that support the reduction of tobacco use in Los Angeles County and the associated disease, disability, and mortality.

A perennial stream or perennial river is a stream or river (channel) that has continuous flow in parts of its stream bed all year round during years of normal rainfall. "Perennial" streams are contrasted with "intermittent" streams which normally cease flowing for weeks or months each year, and with "ephemeral" channels that flow only for hours or days following rainfall.

The Los Angeles County Department of Animal Care and Control (ACC) is one of the largest and most progressive animal control agencies in the United States. The ACC operates six animal shelters serving all unincorporated County areas and 50 contract cities. The ACC covers more than 3,200 square miles of cities, deserts, beaches, and mountains; from the Antelope Valley in the north to the Palos Verdes Peninsula in the south; as far east as the border of San Bernardino County and west all the way to Thousand Oaks. The ACC provides animal control and rescue services 24 hours a day, seven days a week in our service area.