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.

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.

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.

The Criminal Grand Jury of Los Angeles County attends hearings brought by the District Attorney’s Office . The objective of this jury is to determine, on the basis of evidence presented by the District Attorney’s Office, whether certain persons should be charged with crimes an d required to stand trial in Superior Court. The Criminal Grand Jury is an accusatory body and not a trial jury; therefore, the burden of proof is much lower. Specifically, the Criminal Grand Jury must decide if there is a strong suspicion the individual committed the alleged crime.

The Vikings were seafaring north Germanic people who raided, traded, explored, and settled in wide areas of Europe, Asia, and the North Atlantic islands from the late 8th to the mid-11th centuries. The Vikings employed wooden longships with wide, shallow-draft hulls, allowing navigation in rough seas or in shallow river waters. The ships could be landed on beaches, and their light weight enabled them to be hauled over portages. These versatile ships allowed the Vikings to travel as far east as Constantinople and the Volga River in Russia, as far west as Iceland, Greenland, and Newfoundland, and as far south as Nekor. This period of Viking expansion, known as the Viking Age, constitutes an important element of the medieval history of Scandinavia, Great Britain, Ireland, Russia, and the rest of Europe.