Acoustic microscopy acoustic microscope (CSAM), and C-mode scanning acoustic microscope (C-SAM). More recently acoustic microscopes based around picosecond ultrasonics systems have demonstrated acoustic imaging in cells using sub-optical wavelengths working with ultrasonic frequencies into the multi-GHz. Since the vast majority of acoustic microscopes in use today are C-SAM type instruments, this discussion will be limited to these instruments. Ultrasound is broadly defined as any sound having a frequency above 20 kHz, which is approximately the highest frequency that can be detected by the human ear. However, the acoustic microscopes emit ultrasound ranging from 5 MHz to beyond 400 MHz so that micrometre
Above the Influence funding and oversight of Above the Influence ceased, and it transitioned to become a program of the not-for-profit Partnership for Drug-Free Kids. In 2006, the Government Accountability Office released the results of a five-year study, concluding that the previous "My Anti-Drug" campaign was ineffective, and likely counterproductive, leading those exposed to an increased perception that others use marijuana, stating, "analysis also indicated that among current, non-drug-using youth, exposure to the campaign had unfavorable effects on their anti-drug norms and perceptions of other youths’ use of marijuana — that is, greater exposure to the campaign was associated with weaker anti-drug norms