Context and question: The central oscillator generates a self-sustaining rhythm and is driven by two interacting feedback loops that are active at different times of day. The morning loop consists of CCA1 (Circadian and Clock-Associated 1) and LHY (Late Elongated Hypocotyl), which encode closely related MYB transcription factors that regulate circadian rhythms in Arabidopsis, as well as PRR 7 and 9 (Pseudo-Response Regulators.) The evening loop consists of GI (Gigantea) and ELF4, both involved in regulation of flowering time genes. When CCA1 and LHY are overexpressed (under constant light or dark conditions), plants become arrhythmic, and mRNA signals reduce, contributing to a negative feedback loop. Gene expression of CCA1 and LHY oscillates and peaks in the early morning, whereas TOC1 gene expression oscillates and peaks in the early evening. While it was previously hypothesised that these three genes model a negative feedback loop in which over-expressed CCA1 and LHY repress TOC1 and over-expressed TOC1 is a positive regulator of CCA1 and LHY, it was shown in 2012 by Andrew Millar and others that TOC1 in fact serves as a repressor not only of CCA1, LHY, and PRR7 and 9 in the morning loop but also of GI and ELF4 in the evening loop. This finding and further computational modeling of TOC1 gene functions and interactions suggest a reframing of the plant circadian clock as a triple negative-component repressilator model rather than the positive/negative-element feedback loop characterizing the clock in mammals.
When do the CCA1 and LHY function?
Answer: morning
Context and question: Lighthouse Point Park, a public beach run by the city, was a popular tourist destination during the Roaring Twenties, attracting luminaries of the period such as Babe Ruth and Ty Cobb. The park remains popular among New Haveners, and is home to the Five Mile Point Lighthouse, constructed in 1847, and the Lighthouse Point Carousel, constructed in 1916. Five Mile Point Light was decommissioned in 1877 following the construction of Southwest Ledge Light at the entrance of the harbor, which remains in service to this day. Both of the lighthouses and the carousel are listed on the National Register of Historic Places.
What popular tourist site was particularly active during the 20s?
Answer: Lighthouse Point Park
Context and question: Television transmissions resumed from Alexandra Palace in 1946. The BBC Television Service (renamed "BBC tv" in 1960) showed popular programming, including drama, comedies, documentaries, game shows, and soap operas, covering a wide range of genres and regularly competed with ITV to become the channel with the highest ratings for that week. The channel also introduced the science fiction show Doctor Who on 23 November 1963 - at 17:16 - which went on to become one of Britain's most iconic and beloved television programmes.
What did the BBC do with the network, IVT?
Answer:
unanswerable