The Doppler effect (or Doppler shift), named after the Austrian physicist Christian Doppler, who proposed it in 1842 in Prague, is the change in frequency of a wave (or other periodic event) for an observer moving relative to its source. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession.

Reserve Deputy Probation Officers are deputized volunteers who have received special training in order to assist Probation staff in a wide range of supervised responsibilities, that include direct involvement with juvenile an d adult probationers. Reserve Deputies are highly motivated, skilled, and caring people who want to serve their community as a part of the Los Angeles County Probation Department. Reserve Deputies are not a replacement for or an alternative to paid staff, but are intended to be an enhancement to existing resources.

USS Gilliam (APA-57), named for Gilliam County in Oregon, was the lead ship in the her class of attack transports serving in the United States Navy during World War II. She was launched 28 March 1944 under a Maritime Commission contract by the Consolidated Steel Corporation, Wilmington, California; sponsored by Mrs. A. O. Williams of Wilmington; acquired 31 July 1944; and commissioned 1 August 1944, Comdr. H. B. Olsen in command.

Speed skating is a competitive form of ice skating in which the competitors race each other in traveling a certain distance on skates. Types of speed skating are long track speed skating, short track speed skating, and marathon speed skating. Short track speed skating takes place on a smaller rink, normally the size of an ice hockey rink. Distances are shorter than in long track racing, with the longest Olympic race being 3000 meters. Races are usually held as knockouts, with the best two in heats of four or five qualifying for the final race, where medals are awarded. Disqualifications and falls are not uncommon. The sport originates from pack-style events held in North America and was officially sanctioned in the 1970s, becoming an Olympic sport in 1992. Although this form of speed skating is newer, it is growing faster than long track speed skating, largely because short track can be done on an ice hockey rink rather than a long-track oval.

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.