Previous

Instituto di Fisica

Next

Introduction Material and Methods Experimental Results and Discussion Experimental Results and Discussion (cont.) Experimental Results and Discussion (cont.) Conclusion References

Page 1 of 7

In every investigation of a real physical system one is always forced to simplify and idealise the true properties of the system. This process of idealisation of the problem can never be avoided and constitutes the real essence of the physical transaction of a real problem.

In fact, in order to construct a mathematical model of the system under observation, one have to choose the basic factors governing just those features of the behaviour of the system which are of his interest neglecting all the others.

An attempt of trick this procedure by now consolidated from the different centuries of the physical experience doesn't bring in general that to a featureless bulk of information that should be treated by means of the mathematical formalisms whose solution would be extremely cumberstone, if not altogether impossible.

On the other side often the schematization of a simple real system allows to obtain of the useful models to explain the behaviour of more complex systems.

An important aspect to hold in account is that the nature of the idealisation permissible in the analysis of a problem is determined by the whole problem and therefore depends not only on the properties of the analysed system but also from the questions which we will to answer with our analysis.

Since an idealisation of the problem is in any case inevitable the question arise of how far is possible to idealise the properties of the system still obtaining good results.

Only experiments are able to give an answer to this question and to legitimate the idealisation of the real system.

The idealisation of the problem seem to be particularly difficult to make in the case of the study, by means of physical formalisms, of the biological systems and this difficulty is not probably extraneous to the scrubby growth of the biophysics that often appear as a mere application of physical measurement techniques to the biological systems.

In this paper we will expose some characteristic of a biophysical phenomenon which seems to be particularly proper for begin an analysis of the biological systems departing from a physical point of view.

In 1950 B Strehler observed a totally unaspected light emission from green plants some seconds after illumination that at the moment was interpreted as energy remitted from the pigment systems associated to PSII

Starting from 1980 some papers appeared in literature [1,2,3] demonstrating that this light emission was more general and that also cell cultures without any photosystem after illumination exhibit a relaxation dynamics approximated by a hyperbolic decay law .

In the last few years a lots of experimental works [4,13] on several biological systems have shown that there is a close connection between the biological state of the system and the parameters of this phenomenon, referred in literature as delayed fluorescence, delayed luminescence (D.L.), delayed light emission or induced photon emission.

The study of this phenomenon seems to be particularly proper for begin an analysis of the biological systems departing from a physical point of view.

D.L. is in fact a phenomenon relatively simple to measure but able to furnish, by means of a measure of the electromagnetic fields received and emitted by the biological system, important information on the fields and the structures inside to the same system.

Previous

Instituto di Fisica

Next