The response clock started at the onset of the stimulus.
Joni Ernst gave an unbelievably short "official" Republican response (clocking in at a mere nine minutes), spending most of the time competing for the "I was born in a log cabin" modest-beginnings prize.
By identifying the clock frequency range from the core circadian clock genes, we separate the frequency spectrum to different sections containing treatment-frequency (representing up- or down-regulation by an adaptive treatment response), clock-frequency (representing the circadian clock-disruption response) and noise-frequency components.
However, doll faces did not elicit a significantly different response from clocks (t(18) = .20, p>.80; critical p-value = .02 for three comparisons), suggesting that the later positivity uniquely distinguished human faces.
Differences in the response of clock genes to entrainment signals in different tissues have also been observed in mammals, where e.g. per2 responds differently to glucocorticoid changes in certain brain regions (reviewed in [2]).
Since its discovery in the 1950s, the sun compass has been central to our understanding of avian navigation, with the concept of time compensation at its heart, and a response to clock shift its axiomatic test.
It will be of considerable interest to see if the radiation response of Clock −/− mice is similarly intermediate between these other two mouse lines with disruption of the circadian transcriptional activation complex.
We conclude that clock shift experiments alone are neither necessary nor sufficient to identify the occurrence of all conceivable uses of solar information in animal orientation, so that a predictable response to clock shift should not be regarded as an acid test of the use of solar information in navigation.
At the regulatory level, we propose light box (LB, or light response element) and/or clock box (CB, or clock response element) promoters may drive the rhythmic expression of particular gene(s) [ 68] (see below for a discussion on this mechanism).
Thus, in the case of zebrafish peripheral tissues, changes in clock gene transcription appear to contribute to the response of the clock to temperature changes.
