Sentence examples for clock is difficult from inspiring English sources
Since there is no fossil record for N. taihuensis to analyze their cartilage character, the genetic time clock is difficult to calibrate.
A solution to this problem would be to start the GA with several local clocks, but determining an appropriate number of local clocks is difficult.
Precise estimation of the age of separation using a molecular clock approach is difficult due to the lack of reliable calibration points.
Although this model predicts many properties of real circadian clocks, it is difficult to avoid thinking that processes other than gene repression must also be involved.
The Grande Sonnerie, a musical timepiece that sounds the passing hours and quarters like a miniature tower clock, is so difficult to assemble and adjust that only a few watchmakers have mastered the art.
Whereas simplicity of the study design presumably improved acceptability and feasibility, we cannot rule out that patients could be missed because making clinical research around the clock is sometimes difficult in busy EDs.
In the absence of reliable universal molecular clock in bacteria [39], it is difficult to infer divergence times for the different evolutionary steps.
This apparent independence of clock period and wavefront velocity is difficult to reconcile with any model of somitogenesis in which the wavefront arises from coupling between oscillators and in which the period is strictly dependent on the wavefront velocity (Murray et al., 2011).
Finally, though conceptually very elegant, behavioral patterns predicted by SET through pharmacological manipulations are not so evident when analyzing patients' timing behavior and in practice it is difficult to separate clock from memory variance.
However, calibrating the molecular clock can be difficult when the data set involves deep coalescence events [ 42- 44].
In a culture that defines itself in terms of clocks and dollars and duty, it is difficult to allow ourselves to claim the time and mental space to devote to an occupation that results in no visible product.
