Atomic clocks already serve a number of practical purposes: standards bodies like the NIST depend on cesium-based clocks to set international definitions of the second and the hertz (a measure of frequency), and global positioning systems use cesium or rubidium clocks for calibration purposes.
# Time service is used for clock synchronization.
It was important to determine the original colour of the clock face for restoration purposes.
Despite the fact that auto-correlated models of clock relaxation have been shown to provide a significantly better fit than uncorrelated models on phylogenomic datasets [ 56, 57], all analyses were conducted under both models of molecular clock relaxation for comparison purposes.
Incense seal clocks were used for similar occasions and events as the stick clock; while religious purposes were of primary importance, these clocks were also popular at social gatherings, and were used by Chinese scholars and intellectuals.
For all practical purposes, the clocks of the world's markets -- with the exception in some ways of those in Japan -- are set to 9 30 a.m. on Wall Street, when the day's trading begins on the New York Stock Exchange.
Although we have succeeded in recording locomotor activity rhythms in individual nematodes, the high variability between periods and acrophases is indeed a challenge and supports the need of populational studies for screening purposes of circadian clock mutants.
In Arabidopsis, SFPs have been used for several purposes such as mapping clock mutations through bulked segregant analysis (Hazen et al. 2005), the identification of genes for flowering QTLs (Werner et al. 2005), high-density haplotyping of recombinant inbred lines (RILs) (West et al. 2006), and natural variation in genome-wide DNA polymorphism (Borevitz et al. 2007).
During the Middle Ages, clocks were primarily used for religious purposes; the first employed for secular timekeeping emerged around the 15th century.
For example, the fixation of amino acid replacements does not support well any clock, even for the purpose of comparing divergences of different genes within the same organism [ 37].
Kantrowitz created the student loan debt clock, above, which he cautions is for entertainment purposes.
