Abstracts Keynote & Plenary
Abstracts Keynote & Plenary
Abstracts Keynote & Plenary
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essential for mammalian development and health, Perturbation of its dynamics contributes to all<br />
the major disease, including cancer. The discovery by the latestcutting-edging methylomic<br />
approaches and following validation of the epigenetic biomarkers (DNA methylation) in the quality<br />
clinic setting are essential to better stratify the disease and rationale use of therapeutics. In this<br />
presentation, the vital importance of the epigenetic researches to the today’s life science will be<br />
discussed with our own works as paradigms: 1, The potential of DNA methylation biomarker in bodily<br />
fluids for cancer detection and prediction (bladder cancer and lung cancer); 2, the MBD affinity<br />
approaches/the 2nd generation technologies for both low and the sequence resolution methylome in<br />
both health and disease of human; and 3, the first high resolution methylome of the human peripheral<br />
blood mononuclear cells by bisulphite sequencing.<br />
PL-017<br />
Signatures of low-dimensional chaos in the human heartbeat dynamics<br />
Alexander V. Glushkov<br />
ox 24a, Odessa-9, SE, 65009, Ukraine<br />
1,2<br />
1Odessa University, P.O.B<br />
2Russian Academy Sciences, Troitsk, Moscow reg., 142090, Russia<br />
E-mail: glushkov@paco.net<br />
This paper investigates the existence of chaotic behaviour in the human heartbeat dynamics. The<br />
mutual information approach, the correlation integral analysis, the false nearest neighbour algorithm,<br />
the Lyapunov exponents analysis, and the surrogate data method were used in the analysis (the details<br />
of our versions are presented in refs.[1]). In ref. [2] we will firstly adapt the cited methods in the<br />
computational biology and physiology.<br />
The mutual information approach provided<br />
a time lag which is needed to reconstruct phase space. Such<br />
an approach allowed concluding the possible nonlinear nature of process resulting in the heartbeat<br />
amplitudes variations. The correlation dimension method provided a low fractal-dimensional attractor<br />
thus suggesting a possibility of the existence of chaotic behaviour. Based on the attractor dimensions,<br />
the minimum number of variables essential to model the heartbeat amplitudes dynamics for two kinds<br />
of people (absolutely healthy and hypertonic carrier). Significant improvement can be achieved when<br />
additional variables, up to the number of variables sufficient (6), are included in the model. The method<br />
of surrogate data, for detecting nonlinearity, provided significant differences in the correlation<br />
exponents between the original data series and the surrogate data sets. This finding indicates that the<br />
null hypothesis (linear stochastic process) can be rejected. The results from the aforementioned<br />
methods indicate that the heartbeat amplitudes variations exhibits (and hypertonic carrier) a nonlinear<br />
behaviour and possibly low-dimensional chaos. Thus, a short-term prediction based on nonlinear<br />
dynamics is possible. The Lyapunov exponents analysis supported this conclusion. It can be noted that<br />
the nonleading exponents are notoriously difficult to estimate from time series data. Moreover, the<br />
interpretation of inverse Lyapunov exponents as predictability times can results in ambiguous<br />
conclusions. In fact, the degree of instability and predictability can vary considerably throughout phase<br />
space. Though a large number of studies employed the ideas gained from the science of chaos, there<br />
have also been widespread criticisms on the application of chaos theory. Important reasons for this are:<br />
(1) the assumptions with which the chaos identification methods have been developed, i.e. infinite and<br />
noise-free time series; and (2) the inability of the investigative methods to provide irrefutable proof<br />
regarding the existence of chaos. On the one hand, the basis for the criticisms of studies investigating<br />
and reporting existence of chaos in the heartbeat dynamics is our strong belief that they are influenced<br />
by a large number of variables and, therefore, are stochastic. On the other hand, the outcomes of the