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.

Water polo, or water ball, is a team water sport. The playing team consists of six field players and one goalkeeper. The winner of the game is the team that scores the most goals. Game play involves swimming, treading water (using a sort of kicking motion known as "eggbeater kick"), players passing the ball while being defended by opponents, and scoring by throwing the ball into a net defended by a goalie. "Man-up" (or "power play") situations occur frequently. Water polo, therefore, has strong similarities to the land-based game of team handball.

Volunteer hosts went to the airport, picked up assigned students, fed them dinner, took them to the opening lecture at the Clay Center, put them in spare bedrooms for the night, then fed them breakfast this morning and will deliver the outstanding teens to buses that convey them to the mountain retreat where they undergo a month of intensive science training and outdoor fun.

Luckily, this year, enough local families volunteered to host all the brilliant youths. In the past, the number of guest homes sometimes fell short, and some of the visitors slept on cots and sleeping bags at local churches. They're adventurous teens and don't mind this makeshift camp-in but it's better if friendly hosts give them a more personal welcome for their stay.

Los Angeles County Immunization Program efforts are targeted primarily toward pediatric and adolescent immunizations , with some adult immunization activities. Although this Program serves the entire County population, many activities are specifically directed toward communities with children at high risk of under-immunization. The Immunization Program partners with other organizations to provide outreach and immunization services in pockets of need areas , which are defined as those areas with large numbers of un-immunized and under-immunized children.

"In the land of the blind, the one-eyed man is king." - Desiderius Erasmus