第７３回「非線形・統計力学とその周辺」セミナーのご案内

日時：平成１８年３月１４日（火）１７：００−１８：３０

場所：京都大学工学部総合校舎２１３室（吉田キャンパス）

講演者： 松下 貢（中央大学理工学部教授）

講演題目： Long-tailed Distributions of Duration of Life for Disability in Aged People - Revisit to Log-normal Distribution

講演要旨：

       Disability and the resulting lowered quality of life are serious issues
       accompanying increased longevity.  
       Curiously, despite its potential contribution to aging theory, complete
       statistical and etiological structures of this common and unwelcome aging
       phenotype before death have not been well studied.
       Here we analyze characteristic long tails of the duration distributions for
       disabilities in the aged.  
       Log-normal distribution (LND) shows excellent fit with various data on the
       durations of disabilities, irrespective of their severity.  
       The robust long-tailed LND for various phases of disability validates the fact
       that patients in disability undergo series of stochastic subprocesses of many
       independent endogenous diseases, i.e., multiple pathology, until death.  
       A declining force of natural selection after reproduction and trade-off of
       life history through pleiotropy of the genes are considered to be the roots
       of aging.  
       The attenuated selection pressure and the resulting decrease of genetic
       constraints produce an increased opportunity for chance and stochastics.  
 
       Now that we found surprizingly good application of LND above, we decided to
       revisit LND and its new applications.  
       We would like to show several interesting datasets from various disciplines
       which are shown to fit excellently to LND, and then discuss the
       implication.