Triple test Triple test The triple test, also called triple screen, the Kettering test or the Bart's test, is an investigation performed during pregnancy in the second trimester to classify a patient as either high-risk or low-risk for chromosomal abnormalities (and neural tube defects). The term "multiple-marker screening test" is sometimes used instead. This term can encompass the "double test" and "quadruple test" (described below). The Triple screen measures serum levels of AFP, estriol, and beta-hCG, with a 70% sensitivity and 5% false-positive rate. It is complemented in some regions of the United States, as the "Quad screen" (adding inhibin A to
Owned-and-operated television stations in the United States opened up a new spectrum of frequencies on the UHF dial (channels 14–83) for terrestrial television. As an incentive for companies to operate UHF stations, the FCC relaxed the ownership limit for a given entity from five to seven stations, provided that no more than five were on the VHF dial. With this opportunity to expand its roster of O&Os, NBC bought WBUF-TV (channel 17) in Buffalo in 1955 and WKNB-TV (channel 30) in New Britain, Connecticut (near Hartford) in 1957, and changed WKNB's call letters to WNBC-TV (the present-day WNBC in New York City used the WRCA-TV callsign from