Jianzhong Gu | PubMed Health

PubMed2006

Nonlinear modelling approach to human promoter sequences.

By means of the nonlinear modelling technique, we find the nonlinear deterministic structures in the totally 4737 human promoter sequences. These deterministic structures prefer to occur much more outside of a special region around the transcriptional start site. The number and positions of the deterministic structures are basically different for different promoter sequences. Generally, they do not coincide with the CpG islands, the simple repetitive sequences and the low-complexity sequences, which tell us that they should be special structures with biological functions rather than these special segments.

CpG Islands↗

PubMed2002

Fluctuation of the strength function.

We consider a single state stochastically coupled to its stochastic background states. The fluctuation of the strength function of the single state is systematically studied. We find that the upper and lower deviations of the strength function only depend on the ratio of the spreading width over the decay width of the single state and on the ratio of the common decay width over the mean level spacing of the background states. Based on the two fit formulas for the upper and lower deviations, the uncertainties of the full width at half maximum (FWHM) and lifetime of a single state are estimated. They predict the experimental error bars of the FWHM and lifetime. A comparison of the uncertainties with the experimental error bars is made for nuclear giant dipole resonance, which illuminates our theoretical predictions.

Journal Article↗