SACs are those genes with expression up-regulated during leaf senescence. Class I SACs are expressed only during senescence (senescence-specific). Class II SAGs have a basal level of expression during early leaf development, but this level increases during senescence.
Which Sample Rate to use. 44.1 kHz. 44.1 kHz (44100 Hz) is the sampling rate of audio CDs giving a 20 kHz maximum frequency. 20 kHz is the highest frequency generally audible by humans, so making 44.1 kHz the logical choice for most audio material.
Linux: It is often best to choose the default recording and playback device. Recording sources can be chosen if necessary in either alsamixer or pulseaudio volume control (on machines where pulseaudio is the default audio system).